diff --git a/.prettierignore b/.prettierignore
index 7095e7b34d..4edd8069bb 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -7,7 +7,4 @@ packages/react-refresh-utils/**/*.js
 packages/react-refresh-utils/**/*.d.ts
 packages/react-dev-overlay/lib/**
 **/__tmp__/**
-# prettier can't handle the `import type {} from ''` syntax yet
-test/integration/typescript-only-remove-type-imports/**/*.ts
-test/integration/typescript-only-remove-type-imports/**/*.tsx
 lerna.json
diff --git a/.prettierignore_staged b/.prettierignore_staged
index d41a43ad66..3e87a0d626 100644
--- a/.prettierignore_staged
+++ b/.prettierignore_staged
@@ -2,7 +2,4 @@
 **/_next/**
 **/dist/**
 packages/next/compiled/**/*
-# prettier can't handle the `import type {} from ''` syntax yet
-test/integration/typescript-only-remove-type-imports/**/*.ts
-test/integration/typescript-only-remove-type-imports/**/*.tsx
 lerna.json
diff --git a/bench/recursive-copy/run.js b/bench/recursive-copy/run.js
index adff8be65a..c4bad36c88 100644
--- a/bench/recursive-copy/run.js
+++ b/bench/recursive-copy/run.js
@@ -20,7 +20,7 @@ const createSrcFolder = async () => {
       join(srcDir, `folder${i % 5}`, `folder${i + (1 % 5)}`, `file${i}`)
     )
 
-  await Promise.all(files.map(file => fs.outputFile(file, 'hello')))
+  await Promise.all(files.map((file) => fs.outputFile(file, 'hello')))
 }
 
 async function run(fn) {
diff --git a/docs/advanced-features/custom-document.md b/docs/advanced-features/custom-document.md
index f748a0eb8c..f9e60d9797 100644
--- a/docs/advanced-features/custom-document.md
+++ b/docs/advanced-features/custom-document.md
@@ -71,9 +71,9 @@ class MyDocument extends Document {
     ctx.renderPage = () =>
       originalRenderPage({
         // useful for wrapping the whole react tree
-        enhanceApp: App => App,
+        enhanceApp: (App) => App,
         // useful for wrapping in a per-page basis
-        enhanceComponent: Component => Component,
+        enhanceComponent: (Component) => Component,
       })
 
     // Run the parent `getInitialProps`, it now includes the custom `renderPage`
diff --git a/docs/advanced-features/custom-server.md b/docs/advanced-features/custom-server.md
index e1c8f91661..a9a5c89a5a 100644
--- a/docs/advanced-features/custom-server.md
+++ b/docs/advanced-features/custom-server.md
@@ -45,7 +45,7 @@ app.prepare().then(() => {
     } else {
       handle(req, res, parsedUrl)
     }
-  }).listen(3000, err => {
+  }).listen(3000, (err) => {
     if (err) throw err
     console.log('> Ready on http://localhost:3000')
   })
diff --git a/docs/advanced-features/dynamic-import.md b/docs/advanced-features/dynamic-import.md
index 62a9f0241e..bfab9f15ea 100644
--- a/docs/advanced-features/dynamic-import.md
+++ b/docs/advanced-features/dynamic-import.md
@@ -55,7 +55,7 @@ To dynamically import the `Hello` component, you can return it from the [Promise
 import dynamic from 'next/dynamic'
 
 const DynamicComponent = dynamic(() =>
-  import('../components/hello').then(mod => mod.Hello)
+  import('../components/hello').then((mod) => mod.Hello)
 )
 
 function Home() {
diff --git a/docs/api-reference/data-fetching/getInitialProps.md b/docs/api-reference/data-fetching/getInitialProps.md
index 7965c7d0a6..651a8c5cdc 100644
--- a/docs/api-reference/data-fetching/getInitialProps.md
+++ b/docs/api-reference/data-fetching/getInitialProps.md
@@ -29,7 +29,7 @@ function Page({ stars }) {
   return <div>Next stars: {stars}</div>
 }
 
-Page.getInitialProps = async ctx => {
+Page.getInitialProps = async (ctx) => {
   const res = await fetch('https://api.github.com/repos/zeit/next.js')
   const json = await res.json()
   return { stars: json.stargazers_count }
diff --git a/docs/api-reference/next.config.js/custom-webpack-config.md b/docs/api-reference/next.config.js/custom-webpack-config.md
index 5e0f74a565..b4d0f2f393 100644
--- a/docs/api-reference/next.config.js/custom-webpack-config.md
+++ b/docs/api-reference/next.config.js/custom-webpack-config.md
@@ -24,7 +24,7 @@ module.exports = {
     config.plugins.push(new webpack.IgnorePlugin(/\/__tests__\//))
     return config
   },
-  webpackDevMiddleware: config => {
+  webpackDevMiddleware: (config) => {
     // Perform customizations to webpack dev middleware config
     // Important: return the modified config
     return config
diff --git a/docs/api-reference/next.config.js/exportPathMap.md b/docs/api-reference/next.config.js/exportPathMap.md
index 449f00e038..b8f560c786 100644
--- a/docs/api-reference/next.config.js/exportPathMap.md
+++ b/docs/api-reference/next.config.js/exportPathMap.md
@@ -23,7 +23,7 @@ Open `next.config.js` and add the following `exportPathMap` config:
 
 ```js
 module.exports = {
-  exportPathMap: async function(
+  exportPathMap: async function (
     defaultPathMap,
     { dev, dir, outDir, distDir, buildId }
   ) {
diff --git a/docs/api-reference/next/link.md b/docs/api-reference/next/link.md
index e8c6647c18..1f13e4cf57 100644
--- a/docs/api-reference/next/link.md
+++ b/docs/api-reference/next/link.md
@@ -67,7 +67,7 @@ A `Link` to a dynamic route is a combination of the `href` and `as` props. A lin
 ```jsx
 const pids = ['id1', 'id2', 'id3']
 {
-  pids.map(pid => (
+  pids.map((pid) => (
     <Link href="/post/[pid]" as={`/post/${pid}`}>
       <a>Post {pid}</a>
     </Link>
diff --git a/docs/api-reference/next/router.md b/docs/api-reference/next/router.md
index 5f6d63fa25..7648cd35be 100644
--- a/docs/api-reference/next/router.md
+++ b/docs/api-reference/next/router.md
@@ -20,7 +20,7 @@ function ActiveLink({ children, href }) {
     color: router.pathname === href ? 'red' : 'black',
   }
 
-  const handleClick = e => {
+  const handleClick = (e) => {
     e.preventDefault()
     router.push(href)
   }
@@ -178,7 +178,7 @@ import { useCallback, useEffect } from 'react'
 import Router from 'next/router'
 
 export default function Login() {
-  const handleSubmit = useCallback(e => {
+  const handleSubmit = useCallback((e) => {
     e.preventDefault()
 
     fetch('/api/login', {
@@ -187,7 +187,7 @@ export default function Login() {
       body: JSON.stringify({
         /* Form data */
       }),
-    }).then(res => {
+    }).then((res) => {
       // Do a fast client-side transition to the already prefetched dashboard page
       if (res.ok) Router.push('/dashboard')
     })
@@ -283,7 +283,7 @@ For example, to listen to the router event `routeChangeStart`, do the following:
 ```jsx
 import Router from 'next/router'
 
-const handleRouteChange = url => {
+const handleRouteChange = (url) => {
   console.log('App is changing to: ', url)
 }
 
@@ -316,7 +316,7 @@ Router events should be registered when a component mounts ([useEffect](https://
 import Router from 'next/router'
 
 useEffect(() => {
-  const handleRouteChange = url => {
+  const handleRouteChange = (url) => {
     console.log('App is changing to: ', url)
   }
 
diff --git a/docs/api-routes/api-middlewares.md b/docs/api-routes/api-middlewares.md
index 0c172c6eab..3c7cfe92f1 100644
--- a/docs/api-routes/api-middlewares.md
+++ b/docs/api-routes/api-middlewares.md
@@ -94,7 +94,7 @@ const cors = Cors({
 // And to throw an error when an error happens in a middleware
 function runMiddleware(req, res, fn) {
   return new Promise((resolve, reject) => {
-    fn(req, res, result => {
+    fn(req, res, (result) => {
       if (result instanceof Error) {
         return reject(result)
       }
diff --git a/docs/basic-features/data-fetching.md b/docs/basic-features/data-fetching.md
index cfbbe07fc8..f38f802eca 100644
--- a/docs/basic-features/data-fetching.md
+++ b/docs/basic-features/data-fetching.md
@@ -56,7 +56,7 @@ Here’s an example which uses `getStaticProps` to fetch a list of blog posts fr
 function Blog({ posts }) {
   return (
     <ul>
-      {posts.map(post => (
+      {posts.map((post) => (
         <li>{post.title}</li>
       ))}
     </ul>
@@ -100,7 +100,7 @@ For TypeScript, you can use the `GetStaticProps` type from `next`:
 ```ts
 import { GetStaticProps } from 'next'
 
-export const getStaticProps: GetStaticProps = async context => {
+export const getStaticProps: GetStaticProps = async (context) => {
   // ...
 }
 ```
@@ -123,7 +123,7 @@ import path from 'path'
 function Blog({ posts }) {
   return (
     <ul>
-      {posts.map(post => (
+      {posts.map((post) => (
         <li>
           <h3>{post.filename}</h3>
           <p>{post.content}</p>
@@ -140,7 +140,7 @@ export async function getStaticProps() {
   const postsDirectory = path.join(process.cwd(), 'posts')
   const filenames = fs.readdirSync(postsDirectory)
 
-  const posts = filenames.map(filename => {
+  const posts = filenames.map((filename) => {
     const filePath = path.join(postsDirectory, filename)
     const fileContents = fs.readFileSync(filePath, 'utf8')
 
@@ -260,7 +260,7 @@ export async function getStaticPaths() {
   const posts = await res.json()
 
   // Get the paths we want to pre-render based on posts
-  const paths = posts.map(post => ({
+  const paths = posts.map((post) => ({
     params: { id: post.id },
   }))
 
@@ -445,7 +445,7 @@ For TypeScript, you can use the `GetServerSideProps` type from `next`:
 ```ts
 import { GetServerSideProps } from 'next'
 
-export const getServerSideProps: GetServerSideProps = async context => {
+export const getServerSideProps: GetServerSideProps = async (context) => {
   // ...
 }
 ```
diff --git a/docs/basic-features/pages.md b/docs/basic-features/pages.md
index 384a2fb713..17e9ae3f57 100644
--- a/docs/basic-features/pages.md
+++ b/docs/basic-features/pages.md
@@ -93,7 +93,7 @@ Some pages require fetching external data for pre-rendering. There are two scena
 function Blog({ posts }) {
   return (
     <ul>
-      {posts.map(post => (
+      {posts.map((post) => (
         <li>{post.title}</li>
       ))}
     </ul>
@@ -152,7 +152,7 @@ export async function getStaticPaths() {
   const posts = await res.json()
 
   // Get the paths we want to pre-render based on posts
-  const paths = posts.map(post => `/posts/${post.id}`)
+  const paths = posts.map((post) => `/posts/${post.id}`)
 
   // We'll pre-render only these paths at build time.
   // { fallback: false } means other routes should 404.
diff --git a/docs/basic-features/typescript.md b/docs/basic-features/typescript.md
index 072d6f99ac..29e3945878 100644
--- a/docs/basic-features/typescript.md
+++ b/docs/basic-features/typescript.md
@@ -54,7 +54,7 @@ For `getStaticProps`, `getStaticPaths`, and `getServerSideProps`, you can use th
 ```ts
 import { GetStaticProps, GetStaticPaths, GetServerSideProps } from 'next'
 
-export const getStaticProps: GetStaticProps = async context => {
+export const getStaticProps: GetStaticProps = async (context) => {
   // ...
 }
 
@@ -62,7 +62,7 @@ export const getStaticPaths: GetStaticPaths = async () => {
   // ...
 }
 
-export const getServerSideProps: GetServerSideProps = async context => {
+export const getServerSideProps: GetServerSideProps = async (context) => {
   // ...
 }
 ```
diff --git a/docs/routing/introduction.md b/docs/routing/introduction.md
index 68451fd3e4..9fa8c94dca 100644
--- a/docs/routing/introduction.md
+++ b/docs/routing/introduction.md
@@ -90,7 +90,7 @@ The `as` prop can also be generated dynamically. For example, to show a list of
 function Home({ posts }) {
   return (
     <ul>
-      {posts.map(post => (
+      {posts.map((post) => (
         <li key={post.id}>
           <Link href="/blog/[slug]" as={`/blog/${post.slug}`}>
             <a>{post.title}</a>
diff --git a/docs/upgrading.md b/docs/upgrading.md
index e231c1bb56..9b3b16fa9d 100644
--- a/docs/upgrading.md
+++ b/docs/upgrading.md
@@ -171,8 +171,8 @@ import dynamic from 'next/dynamic'
 const HelloBundle = dynamic({
   modules: () => {
     const components = {
-      Hello1: () => import('../components/hello1').then(m => m.default),
-      Hello2: () => import('../components/hello2').then(m => m.default),
+      Hello1: () => import('../components/hello1').then((m) => m.default),
+      Hello2: () => import('../components/hello2').then((m) => m.default),
     }
 
     return components
diff --git a/errors/export-path-mismatch.md b/errors/export-path-mismatch.md
index ecf3a75faf..bbd0abdbca 100644
--- a/errors/export-path-mismatch.md
+++ b/errors/export-path-mismatch.md
@@ -11,7 +11,7 @@ Change your `exportPathMap` function in `next.config.js` to have a path that mat
 
 ```js
 module.exports = {
-  exportPathMap: function() {
+  exportPathMap: function () {
     return {
       '/': { page: '/' },
       // '/blog/nextjs': { page: '/blog/[post]/comment/[id]' },        // wrong
diff --git a/errors/get-initial-props-as-an-instance-method.md b/errors/get-initial-props-as-an-instance-method.md
index fb67e95bea..115882f4b9 100644
--- a/errors/get-initial-props-as-an-instance-method.md
+++ b/errors/get-initial-props-as-an-instance-method.md
@@ -23,7 +23,7 @@ export default class YourEntryComponent extends React.Component {
 or
 
 ```js
-const YourEntryComponent = function() {
+const YourEntryComponent = function () {
   return 'foo'
 }
 
diff --git a/errors/next-dynamic-modules.md b/errors/next-dynamic-modules.md
index 74838f3029..a5fa9a1c98 100644
--- a/errors/next-dynamic-modules.md
+++ b/errors/next-dynamic-modules.md
@@ -18,8 +18,8 @@ import dynamic from 'next/dynamic'
 const HelloBundle = dynamic({
   modules: () => {
     const components = {
-      Hello1: () => import('../components/hello1').then(m => m.default),
-      Hello2: () => import('../components/hello2').then(m => m.default),
+      Hello1: () => import('../components/hello1').then((m) => m.default),
+      Hello2: () => import('../components/hello2').then((m) => m.default),
     }
 
     return components
diff --git a/errors/no-on-app-updated-hook.md b/errors/no-on-app-updated-hook.md
index c2ce7c5d7e..4b6463b0ff 100644
--- a/errors/no-on-app-updated-hook.md
+++ b/errors/no-on-app-updated-hook.md
@@ -5,7 +5,7 @@ Due to [this bug fix](https://github.com/zeit/next.js/pull/3849), we had to remo
 We use this hook to detect a new app deployment when switching pages and act accordingly. Although there are many things you can do in this hook, it's often used to navigate the page via the server as shown below:
 
 ```js
-Router.onAppUpdated = function(nextRoute) {
+Router.onAppUpdated = function (nextRoute) {
   location.href = nextRoute
 }
 ```
@@ -17,7 +17,7 @@ One real use of this hook is to persist your application state to local-storage
 This is code for that:
 
 ```js
-window.onbeforeunload = function(e) {
+window.onbeforeunload = function (e) {
   // Get the application state (usually from a store like Redux)
   const appState = {}
   localStorage.setItem('app-state', JSON.stringify(appState))
diff --git a/errors/promise-in-next-config.md b/errors/promise-in-next-config.md
index 7fb48b3b00..f39ce7786f 100644
--- a/errors/promise-in-next-config.md
+++ b/errors/promise-in-next-config.md
@@ -6,7 +6,7 @@ The webpack function in `next.config.js` returned a promise which is not support
 
 ```js
 module.exports = {
-  webpack: async function(config) {
+  webpack: async function (config) {
     return config
   },
 }
diff --git a/examples/amp-first/components/Layout.js b/examples/amp-first/components/Layout.js
index 6abebffa4d..8653c88488 100644
--- a/examples/amp-first/components/Layout.js
+++ b/examples/amp-first/components/Layout.js
@@ -10,7 +10,7 @@ const THEME_COLOR = '#005af0'
  *
  * @param {Props} props
  */
-const Layout = props => (
+const Layout = (props) => (
   <>
     <NextHead>
       <title>{props.title || ''}</title>
diff --git a/examples/amp-first/pages/index.js b/examples/amp-first/pages/index.js
index ceff4b62e3..f0c9ca2603 100644
--- a/examples/amp-first/pages/index.js
+++ b/examples/amp-first/pages/index.js
@@ -9,7 +9,7 @@ import {
 
 export const config = { amp: true }
 
-const Home = props => (
+const Home = (props) => (
   <>
     <Layout
       title="Welcome to AMP"
diff --git a/examples/api-routes-apollo-server-and-client-auth/apollo/client.js b/examples/api-routes-apollo-server-and-client-auth/apollo/client.js
index 55135ad4eb..b679f430ce 100644
--- a/examples/api-routes-apollo-server-and-client-auth/apollo/client.js
+++ b/examples/api-routes-apollo-server-and-client-auth/apollo/client.js
@@ -37,7 +37,7 @@ export function withApollo(PageComponent, { ssr = true } = {}) {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithApollo.getInitialProps = async ctx => {
+    WithApollo.getInitialProps = async (ctx) => {
       const { AppTree } = ctx
 
       // Initialize ApolloClient, add it to the ctx object so
diff --git a/examples/api-routes-apollo-server-and-client-auth/apollo/resolvers.js b/examples/api-routes-apollo-server-and-client-auth/apollo/resolvers.js
index 76e6d851cd..50fe47ea0c 100644
--- a/examples/api-routes-apollo-server-and-client-auth/apollo/resolvers.js
+++ b/examples/api-routes-apollo-server-and-client-auth/apollo/resolvers.js
@@ -31,7 +31,7 @@ export const resolvers = {
         try {
           const { id, email } = jwt.verify(token, JWT_SECRET)
 
-          return users.find(user => user.id === id && user.email === email)
+          return users.find((user) => user.id === id && user.email === email)
         } catch {
           throw new AuthenticationError(
             'Authentication token is invalid, please log in'
@@ -50,7 +50,7 @@ export const resolvers = {
     },
 
     async signIn(_parent, args, context, _info) {
-      const user = users.find(user => user.email === args.input.email)
+      const user = users.find((user) => user.email === args.input.email)
 
       if (user && validPassword(user, args.input.password)) {
         const token = jwt.sign(
diff --git a/examples/api-routes-apollo-server-and-client/apollo/client.js b/examples/api-routes-apollo-server-and-client/apollo/client.js
index d39cf04f04..908471d634 100644
--- a/examples/api-routes-apollo-server-and-client/apollo/client.js
+++ b/examples/api-routes-apollo-server-and-client/apollo/client.js
@@ -37,7 +37,7 @@ export function withApollo(PageComponent, { ssr = true } = {}) {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithApollo.getInitialProps = async ctx => {
+    WithApollo.getInitialProps = async (ctx) => {
       const { AppTree } = ctx
 
       // Initialize ApolloClient, add it to the ctx object so
diff --git a/examples/api-routes-cors/lib/init-middleware.js b/examples/api-routes-cors/lib/init-middleware.js
index 9b7dfdab4d..8af0a8fe7b 100644
--- a/examples/api-routes-cors/lib/init-middleware.js
+++ b/examples/api-routes-cors/lib/init-middleware.js
@@ -3,7 +3,7 @@
 export default function initMiddleware(middleware) {
   return (req, res) =>
     new Promise((resolve, reject) => {
-      middleware(req, res, result => {
+      middleware(req, res, (result) => {
         if (result instanceof Error) {
           return reject(result)
         }
diff --git a/examples/api-routes-graphql/pages/index.js b/examples/api-routes-graphql/pages/index.js
index e62fb7bc24..9a0bbc3b79 100644
--- a/examples/api-routes-graphql/pages/index.js
+++ b/examples/api-routes-graphql/pages/index.js
@@ -1,6 +1,6 @@
 import useSWR from 'swr'
 
-const fetcher = query =>
+const fetcher = (query) =>
   fetch('/api/graphql', {
     method: 'POST',
     headers: {
@@ -8,8 +8,8 @@ const fetcher = query =>
     },
     body: JSON.stringify({ query }),
   })
-    .then(res => res.json())
-    .then(json => json.data)
+    .then((res) => res.json())
+    .then((json) => json.data)
 
 export default function Index() {
   const { data, error } = useSWR('{ users { name } }', fetcher)
diff --git a/examples/api-routes-middleware/pages/index.js b/examples/api-routes-middleware/pages/index.js
index 9f745a0198..51c784cc10 100644
--- a/examples/api-routes-middleware/pages/index.js
+++ b/examples/api-routes-middleware/pages/index.js
@@ -1,6 +1,6 @@
 import useSWR from 'swr'
 
-const fetcher = url => fetch(url).then(res => res.text())
+const fetcher = (url) => fetch(url).then((res) => res.text())
 
 export default function Index() {
   const { data, error } = useSWR('/api/cookies', fetcher)
diff --git a/examples/api-routes-middleware/utils/cookies.js b/examples/api-routes-middleware/utils/cookies.js
index 6409c73617..9e48b0405d 100644
--- a/examples/api-routes-middleware/utils/cookies.js
+++ b/examples/api-routes-middleware/utils/cookies.js
@@ -18,7 +18,7 @@ const cookie = (res, name, value, options = {}) => {
 /**
  * Adds `cookie` function on `res.cookie` to set cookies for response
  */
-const cookies = handler => (req, res) => {
+const cookies = (handler) => (req, res) => {
   res.cookie = (name, value, options) => cookie(res, name, value, options)
 
   return handler(req, res)
diff --git a/examples/api-routes-rest/pages/index.js b/examples/api-routes-rest/pages/index.js
index 861919c5e3..eb16fb1d47 100644
--- a/examples/api-routes-rest/pages/index.js
+++ b/examples/api-routes-rest/pages/index.js
@@ -1,7 +1,7 @@
 import useSwr from 'swr'
 import Link from 'next/link'
 
-const fetcher = url => fetch(url).then(res => res.json())
+const fetcher = (url) => fetch(url).then((res) => res.json())
 
 export default function Index() {
   const { data, error } = useSwr('/api/users', fetcher)
@@ -11,7 +11,7 @@ export default function Index() {
 
   return (
     <ul>
-      {data.map(user => (
+      {data.map((user) => (
         <li key={user.id}>
           <Link href="/user/[id]" as={`/user/${user.id}`}>
             <a>{`User ${user.id}`}</a>
diff --git a/examples/api-routes-rest/pages/user/[id].js b/examples/api-routes-rest/pages/user/[id].js
index ab8bcfde79..007875c358 100644
--- a/examples/api-routes-rest/pages/user/[id].js
+++ b/examples/api-routes-rest/pages/user/[id].js
@@ -1,7 +1,7 @@
 import { useRouter } from 'next/router'
 import useSwr from 'swr'
 
-const fetcher = url => fetch(url).then(res => res.json())
+const fetcher = (url) => fetch(url).then((res) => res.json())
 
 export default function User() {
   const router = useRouter()
diff --git a/examples/api-routes/pages/api/people/[id].js b/examples/api-routes/pages/api/people/[id].js
index a118dc41a4..d114988e59 100644
--- a/examples/api-routes/pages/api/people/[id].js
+++ b/examples/api-routes/pages/api/people/[id].js
@@ -1,7 +1,7 @@
 import { people } from '../../../data'
 
 export default ({ query: { id } }, res) => {
-  const filtered = people.filter(p => p.id === id)
+  const filtered = people.filter((p) => p.id === id)
 
   // User with id exists
   if (filtered.length > 0) {
diff --git a/examples/api-routes/pages/index.js b/examples/api-routes/pages/index.js
index c619a471c7..2043d223ae 100644
--- a/examples/api-routes/pages/index.js
+++ b/examples/api-routes/pages/index.js
@@ -1,7 +1,7 @@
 import useSWR from 'swr'
 import Person from '../components/Person'
 
-const fetcher = url => fetch(url).then(res => res.json())
+const fetcher = (url) => fetch(url).then((res) => res.json())
 
 export default function Index() {
   const { data, error } = useSWR('/api/people', fetcher)
diff --git a/examples/api-routes/pages/person/[id].js b/examples/api-routes/pages/person/[id].js
index 7e9add5e61..0ff5e77edf 100644
--- a/examples/api-routes/pages/person/[id].js
+++ b/examples/api-routes/pages/person/[id].js
@@ -1,7 +1,7 @@
 import { useRouter } from 'next/router'
 import useSWR from 'swr'
 
-const fetcher = async url => {
+const fetcher = async (url) => {
   const res = await fetch(url)
   const data = await res.json()
 
diff --git a/examples/auth0/lib/user.js b/examples/auth0/lib/user.js
index 76c3397bda..8ff0e58610 100644
--- a/examples/auth0/lib/user.js
+++ b/examples/auth0/lib/user.js
@@ -48,7 +48,7 @@ export function useFetchUser({ required } = {}) {
       setLoading(true)
       let isMounted = true
 
-      fetchUser().then(user => {
+      fetchUser().then((user) => {
         // Only set the user if the component is still mounted
         if (isMounted) {
           // When the user is not logged in but login is required
diff --git a/examples/blog-starter/components/more-stories.js b/examples/blog-starter/components/more-stories.js
index c4c1bf7dfa..dcdd9b4e6a 100644
--- a/examples/blog-starter/components/more-stories.js
+++ b/examples/blog-starter/components/more-stories.js
@@ -7,7 +7,7 @@ export default function MoreStories({ posts }) {
         More Stories
       </h2>
       <div className="grid grid-cols-1 md:grid-cols-2 md:col-gap-16 lg:col-gap-32 row-gap-20 md:row-gap-32 mb-32">
-        {posts.map(post => (
+        {posts.map((post) => (
           <PostPreview
             key={post.slug}
             title={post.title}
diff --git a/examples/blog-starter/lib/api.js b/examples/blog-starter/lib/api.js
index 550b604707..f684833c7c 100644
--- a/examples/blog-starter/lib/api.js
+++ b/examples/blog-starter/lib/api.js
@@ -17,7 +17,7 @@ export function getPostBySlug(slug, fields = []) {
   const items = {}
 
   // Ensure only the minimal needed data is exposed
-  fields.forEach(field => {
+  fields.forEach((field) => {
     if (field === 'slug') {
       items[field] = realSlug
     }
@@ -36,7 +36,7 @@ export function getPostBySlug(slug, fields = []) {
 export function getAllPosts(fields = []) {
   const slugs = getPostSlugs()
   const posts = slugs
-    .map(slug => getPostBySlug(slug, fields))
+    .map((slug) => getPostBySlug(slug, fields))
     // sort posts by date in descending order
     .sort((post1, post2) => (post1.date > post2.date ? '-1' : '1'))
   return posts
diff --git a/examples/blog-starter/lib/markdownToHtml.js b/examples/blog-starter/lib/markdownToHtml.js
index e12b916d5d..aebc42164b 100644
--- a/examples/blog-starter/lib/markdownToHtml.js
+++ b/examples/blog-starter/lib/markdownToHtml.js
@@ -2,8 +2,6 @@ import remark from 'remark'
 import html from 'remark-html'
 
 export default async function markdownToHtml(markdown) {
-  const result = await remark()
-    .use(html)
-    .process(markdown)
+  const result = await remark().use(html).process(markdown)
   return result.toString()
 }
diff --git a/examples/blog-starter/pages/posts/[slug].js b/examples/blog-starter/pages/posts/[slug].js
index a5cc1f2549..efad32b7dd 100644
--- a/examples/blog-starter/pages/posts/[slug].js
+++ b/examples/blog-starter/pages/posts/[slug].js
@@ -72,7 +72,7 @@ export async function getStaticPaths() {
   const posts = getAllPosts(['slug'])
 
   return {
-    paths: posts.map(posts => {
+    paths: posts.map((posts) => {
       return {
         params: {
           slug: posts.slug,
diff --git a/examples/cms-contentful/components/more-stories.js b/examples/cms-contentful/components/more-stories.js
index c4c1bf7dfa..dcdd9b4e6a 100644
--- a/examples/cms-contentful/components/more-stories.js
+++ b/examples/cms-contentful/components/more-stories.js
@@ -7,7 +7,7 @@ export default function MoreStories({ posts }) {
         More Stories
       </h2>
       <div className="grid grid-cols-1 md:grid-cols-2 md:col-gap-16 lg:col-gap-32 row-gap-20 md:row-gap-32 mb-32">
-        {posts.map(post => (
+        {posts.map((post) => (
           <PostPreview
             key={post.slug}
             title={post.title}
diff --git a/examples/cms-contentful/contentful/setup.js b/examples/cms-contentful/contentful/setup.js
index 944d05a79b..e3791b8967 100644
--- a/examples/cms-contentful/contentful/setup.js
+++ b/examples/cms-contentful/contentful/setup.js
@@ -19,4 +19,4 @@ spaceImport({
   content: exportFile,
 })
   .then(() => console.log('The content model of your space is set up!'))
-  .catch(e => console.error(e))
+  .catch((e) => console.error(e))
diff --git a/examples/cms-contentful/lib/api.js b/examples/cms-contentful/lib/api.js
index 6105e19790..9b4b6893fa 100644
--- a/examples/cms-contentful/lib/api.js
+++ b/examples/cms-contentful/lib/api.js
@@ -11,7 +11,7 @@ const previewClient = createClient({
   host: 'preview.contentful.com',
 })
 
-const getClient = preview => (preview ? previewClient : client)
+const getClient = (preview) => (preview ? previewClient : client)
 
 function parseAuthor({ fields }) {
   return {
@@ -50,7 +50,7 @@ export async function getAllPostsWithSlug() {
     content_type: 'post',
     select: 'fields.slug',
   })
-  return parsePostEntries(entries, post => post.fields)
+  return parsePostEntries(entries, (post) => post.fields)
 }
 
 export async function getAllPostsForHome(preview) {
diff --git a/examples/cms-contentful/postcss.config.js b/examples/cms-contentful/postcss.config.js
index 0daed9b073..72eae8d0fe 100644
--- a/examples/cms-contentful/postcss.config.js
+++ b/examples/cms-contentful/postcss.config.js
@@ -9,7 +9,8 @@ module.exports = {
               './pages/**/*.{js,jsx,ts,tsx}',
               './components/**/*.{js,jsx,ts,tsx}',
             ],
-            defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
+            defaultExtractor: (content) =>
+              content.match(/[\w-/:]+(?<!:)/g) || [],
           },
         ]
       : undefined,
diff --git a/examples/cms-datocms/components/more-stories.js b/examples/cms-datocms/components/more-stories.js
index c4c1bf7dfa..dcdd9b4e6a 100644
--- a/examples/cms-datocms/components/more-stories.js
+++ b/examples/cms-datocms/components/more-stories.js
@@ -7,7 +7,7 @@ export default function MoreStories({ posts }) {
         More Stories
       </h2>
       <div className="grid grid-cols-1 md:grid-cols-2 md:col-gap-16 lg:col-gap-32 row-gap-20 md:row-gap-32 mb-32">
-        {posts.map(post => (
+        {posts.map((post) => (
           <PostPreview
             key={post.slug}
             title={post.title}
diff --git a/examples/cms-datocms/lib/markdownToHtml.js b/examples/cms-datocms/lib/markdownToHtml.js
index cc1fe05777..45577d599f 100644
--- a/examples/cms-datocms/lib/markdownToHtml.js
+++ b/examples/cms-datocms/lib/markdownToHtml.js
@@ -2,8 +2,6 @@ import remark from 'remark'
 import html from 'remark-html'
 
 export default async function markdownToHtml(markdown) {
-  const result = await remark()
-    .use(html)
-    .processSync(markdown)
+  const result = await remark().use(html).processSync(markdown)
   return result.toString()
 }
diff --git a/examples/cms-datocms/pages/posts/[slug].js b/examples/cms-datocms/pages/posts/[slug].js
index 2741ad30c0..62ebd17053 100644
--- a/examples/cms-datocms/pages/posts/[slug].js
+++ b/examples/cms-datocms/pages/posts/[slug].js
@@ -69,7 +69,7 @@ export async function getStaticProps({ params, preview = false }) {
 export async function getStaticPaths() {
   const allPosts = await getAllPostsWithSlug()
   return {
-    paths: allPosts?.map(post => `/posts/${post.slug}`) || [],
+    paths: allPosts?.map((post) => `/posts/${post.slug}`) || [],
     fallback: true,
   }
 }
diff --git a/examples/cms-datocms/postcss.config.js b/examples/cms-datocms/postcss.config.js
index 0daed9b073..72eae8d0fe 100644
--- a/examples/cms-datocms/postcss.config.js
+++ b/examples/cms-datocms/postcss.config.js
@@ -9,7 +9,8 @@ module.exports = {
               './pages/**/*.{js,jsx,ts,tsx}',
               './components/**/*.{js,jsx,ts,tsx}',
             ],
-            defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
+            defaultExtractor: (content) =>
+              content.match(/[\w-/:]+(?<!:)/g) || [],
           },
         ]
       : undefined,
diff --git a/examples/cms-prismic/postcss.config.js b/examples/cms-prismic/postcss.config.js
index 0daed9b073..72eae8d0fe 100644
--- a/examples/cms-prismic/postcss.config.js
+++ b/examples/cms-prismic/postcss.config.js
@@ -9,7 +9,8 @@ module.exports = {
               './pages/**/*.{js,jsx,ts,tsx}',
               './components/**/*.{js,jsx,ts,tsx}',
             ],
-            defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
+            defaultExtractor: (content) =>
+              content.match(/[\w-/:]+(?<!:)/g) || [],
           },
         ]
       : undefined,
diff --git a/examples/cms-sanity/components/cover-image.js b/examples/cms-sanity/components/cover-image.js
index 91a4a56c01..e6e25ae781 100644
--- a/examples/cms-sanity/components/cover-image.js
+++ b/examples/cms-sanity/components/cover-image.js
@@ -11,11 +11,7 @@ export default function CoverImage({ title, url, slug }) {
       className={cn('shadow-small', {
         'hover:shadow-medium transition-shadow duration-200': slug,
       })}
-      src={imageBuilder
-        .image(url)
-        .height(1000)
-        .width(2000)
-        .url()}
+      src={imageBuilder.image(url).height(1000).width(2000).url()}
     />
   )
 
diff --git a/examples/cms-sanity/components/more-stories.js b/examples/cms-sanity/components/more-stories.js
index c4c1bf7dfa..dcdd9b4e6a 100644
--- a/examples/cms-sanity/components/more-stories.js
+++ b/examples/cms-sanity/components/more-stories.js
@@ -7,7 +7,7 @@ export default function MoreStories({ posts }) {
         More Stories
       </h2>
       <div className="grid grid-cols-1 md:grid-cols-2 md:col-gap-16 lg:col-gap-32 row-gap-20 md:row-gap-32 mb-32">
-        {posts.map(post => (
+        {posts.map((post) => (
           <PostPreview
             key={post.slug}
             title={post.title}
diff --git a/examples/cms-sanity/lib/api.js b/examples/cms-sanity/lib/api.js
index 8dc7aa19ad..11211c2694 100644
--- a/examples/cms-sanity/lib/api.js
+++ b/examples/cms-sanity/lib/api.js
@@ -1,9 +1,9 @@
 import client, { previewClient } from './sanity'
 import sanityImage from '@sanity/image-url'
 
-const getUniquePosts = posts => {
+const getUniquePosts = (posts) => {
   const slugs = new Set()
-  return posts.filter(post => {
+  return posts.filter((post) => {
     if (slugs.has(post.slug)) {
       return false
     } else {
@@ -23,7 +23,7 @@ const postFields = `
   'author': author->{name, 'picture': picture.asset->url},
 `
 
-const getClient = preview => (preview ? previewClient : client)
+const getClient = (preview) => (preview ? previewClient : client)
 
 export const imageBuilder = sanityImage(client)
 
@@ -62,7 +62,7 @@ export async function getPostAndMorePosts(slug, preview) {
       }`,
         { slug }
       )
-      .then(res => res?.[0]),
+      .then((res) => res?.[0]),
     curClient.fetch(
       `*[_type == "post" && slug.current != $slug] | order(date desc, _updatedAt desc){
         ${postFields}
diff --git a/examples/cms-sanity/pages/posts/[slug].js b/examples/cms-sanity/pages/posts/[slug].js
index cc72e87df3..fc235ad7c8 100644
--- a/examples/cms-sanity/pages/posts/[slug].js
+++ b/examples/cms-sanity/pages/posts/[slug].js
@@ -64,7 +64,7 @@ export async function getStaticPaths() {
   const allPosts = await getAllPostsWithSlug()
   return {
     paths:
-      allPosts?.map(post => ({
+      allPosts?.map((post) => ({
         params: {
           slug: post.slug,
         },
diff --git a/examples/cms-sanity/postcss.config.js b/examples/cms-sanity/postcss.config.js
index 23ffee56ff..f9328b6f35 100644
--- a/examples/cms-sanity/postcss.config.js
+++ b/examples/cms-sanity/postcss.config.js
@@ -10,7 +10,7 @@ module.exports = {
                 './pages/**/*.{js,jsx,ts,tsx}',
                 './components/**/*.{js,jsx,ts,tsx}',
               ],
-              defaultExtractor: content =>
+              defaultExtractor: (content) =>
                 content.match(/[\w-/:]+(?<!:)/g) || [],
             },
           ],
diff --git a/examples/cms-takeshape/components/more-stories.js b/examples/cms-takeshape/components/more-stories.js
index c4c1bf7dfa..dcdd9b4e6a 100644
--- a/examples/cms-takeshape/components/more-stories.js
+++ b/examples/cms-takeshape/components/more-stories.js
@@ -7,7 +7,7 @@ export default function MoreStories({ posts }) {
         More Stories
       </h2>
       <div className="grid grid-cols-1 md:grid-cols-2 md:col-gap-16 lg:col-gap-32 row-gap-20 md:row-gap-32 mb-32">
-        {posts.map(post => (
+        {posts.map((post) => (
           <PostPreview
             key={post.slug}
             title={post.title}
diff --git a/examples/cms-takeshape/lib/markdownToHtml.js b/examples/cms-takeshape/lib/markdownToHtml.js
index cc1fe05777..45577d599f 100644
--- a/examples/cms-takeshape/lib/markdownToHtml.js
+++ b/examples/cms-takeshape/lib/markdownToHtml.js
@@ -2,8 +2,6 @@ import remark from 'remark'
 import html from 'remark-html'
 
 export default async function markdownToHtml(markdown) {
-  const result = await remark()
-    .use(html)
-    .processSync(markdown)
+  const result = await remark().use(html).processSync(markdown)
   return result.toString()
 }
diff --git a/examples/cms-takeshape/pages/posts/[slug].js b/examples/cms-takeshape/pages/posts/[slug].js
index 185c406273..b546d4e918 100644
--- a/examples/cms-takeshape/pages/posts/[slug].js
+++ b/examples/cms-takeshape/pages/posts/[slug].js
@@ -80,7 +80,7 @@ export async function getStaticProps({ params, preview = false }) {
 export async function getStaticPaths() {
   const allPosts = await getAllPostsWithSlug()
   return {
-    paths: allPosts?.map(post => `/posts/${post.slug}`) || [],
+    paths: allPosts?.map((post) => `/posts/${post.slug}`) || [],
     fallback: true,
   }
 }
diff --git a/examples/cms-takeshape/postcss.config.js b/examples/cms-takeshape/postcss.config.js
index 0daed9b073..72eae8d0fe 100644
--- a/examples/cms-takeshape/postcss.config.js
+++ b/examples/cms-takeshape/postcss.config.js
@@ -9,7 +9,8 @@ module.exports = {
               './pages/**/*.{js,jsx,ts,tsx}',
               './components/**/*.{js,jsx,ts,tsx}',
             ],
-            defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
+            defaultExtractor: (content) =>
+              content.match(/[\w-/:]+(?<!:)/g) || [],
           },
         ]
       : undefined,
diff --git a/examples/custom-server-actionhero/README.md b/examples/custom-server-actionhero/README.md
index e67268f48a..9d8c4baf6c 100644
--- a/examples/custom-server-actionhero/README.md
+++ b/examples/custom-server-actionhero/README.md
@@ -54,7 +54,7 @@ module.exports = class NextInitializer extends Initializer {
 
   async initialize() {
     api.next = {
-      render: async connection => {
+      render: async (connection) => {
         if (connection.type !== 'web') {
           throw new Error('Connections for NEXT apps must be of type "web"')
         }
@@ -111,7 +111,7 @@ Note that this is where the websocket server, if you enable it, will place the `
 // config/routes.js
 
 exports['default'] = {
-  routes: api => {
+  routes: (api) => {
     return {
       get: [
         { path: '/time', action: 'time' },
diff --git a/examples/custom-server-actionhero/config/api.js b/examples/custom-server-actionhero/config/api.js
index 56d1fb0ed9..ce0cc0b76a 100644
--- a/examples/custom-server-actionhero/config/api.js
+++ b/examples/custom-server-actionhero/config/api.js
@@ -1,7 +1,7 @@
 const path = require('path')
 
 exports['default'] = {
-  general: api => {
+  general: (api) => {
     const packageJSON = require(api.projectRoot + path.sep + 'package.json')
 
     return {
@@ -65,7 +65,7 @@ exports['default'] = {
 }
 
 exports.test = {
-  general: api => {
+  general: (api) => {
     return {
       id: 'test-server-' + process.pid,
       serverToken: 'serverToken-' + process.pid,
@@ -86,7 +86,7 @@ exports.test = {
 }
 
 exports.production = {
-  general: api => {
+  general: (api) => {
     return {
       fileRequestLogLevel: 'debug',
       developmentMode: false,
diff --git a/examples/custom-server-actionhero/config/errors.js b/examples/custom-server-actionhero/config/errors.js
index f801f3a6f4..247a5a5c6b 100644
--- a/examples/custom-server-actionhero/config/errors.js
+++ b/examples/custom-server-actionhero/config/errors.js
@@ -1,6 +1,6 @@
 // error messages can be strings of objects
 exports['default'] = {
-  errors: api => {
+  errors: (api) => {
     return {
       _toExpand: false,
 
@@ -10,28 +10,28 @@ exports['default'] = {
 
       serializers: {
         servers: {
-          web: error => {
+          web: (error) => {
             if (error.message) {
               return String(error.message)
             } else {
               return error
             }
           },
-          websocket: error => {
+          websocket: (error) => {
             if (error.message) {
               return String(error.message)
             } else {
               return error
             }
           },
-          socket: error => {
+          socket: (error) => {
             if (error.message) {
               return String(error.message)
             } else {
               return error
             }
           },
-          specHelper: error => {
+          specHelper: (error) => {
             if (error.message) {
               return 'Error: ' + String(error.message)
             } else {
@@ -62,12 +62,12 @@ exports['default'] = {
       },
 
       // user requested an unknown action
-      unknownAction: data => {
+      unknownAction: (data) => {
         return data.connection.localize('actionhero.errors.unknownAction')
       },
 
       // action not useable by this client/server type
-      unsupportedServerType: data => {
+      unsupportedServerType: (data) => {
         return data.connection.localize([
           'actionhero.errors.unsupportedServerType',
           { type: data.connection.type },
@@ -75,13 +75,13 @@ exports['default'] = {
       },
 
       // action failed because server is mid-shutdown
-      serverShuttingDown: data => {
+      serverShuttingDown: (data) => {
         return data.connection.localize('actionhero.errors.serverShuttingDown')
       },
 
       // action failed because this client already has too many pending acitons
       // limit defined in api.config.general.simultaneousActions
-      tooManyPendingActions: data => {
+      tooManyPendingActions: (data) => {
         return data.connection.localize(
           'actionhero.errors.tooManyPendingActions'
         )
@@ -100,12 +100,12 @@ exports['default'] = {
 
       // The body message to accompany 404 (file not found) errors regarding flat files
       // You may want to load in the contnet of 404.html or similar
-      fileNotFound: connection => {
+      fileNotFound: (connection) => {
         return connection.localize(['actionhero.errors.fileNotFound'])
       },
 
       // user didn't request a file
-      fileNotProvided: connection => {
+      fileNotProvided: (connection) => {
         return connection.localize('actionhero.errors.fileNotProvided')
       },
 
@@ -135,7 +135,7 @@ exports['default'] = {
         ])
       },
 
-      connectionRoomAndMessage: connection => {
+      connectionRoomAndMessage: (connection) => {
         return connection.localize('actionhero.errors.connectionRoomAndMessage')
       },
 
@@ -153,21 +153,21 @@ exports['default'] = {
         ])
       },
 
-      connectionRoomHasBeenDeleted: room => {
+      connectionRoomHasBeenDeleted: (room) => {
         return api.i18n.localize(
           'actionhero.errors.connectionRoomHasBeenDeleted'
         )
       },
 
-      connectionRoomNotExist: room => {
+      connectionRoomNotExist: (room) => {
         return api.i18n.localize('actionhero.errors.connectionRoomNotExist')
       },
 
-      connectionRoomExists: room => {
+      connectionRoomExists: (room) => {
         return api.i18n.localize('actionhero.errors.connectionRoomExists')
       },
 
-      connectionRoomRequired: room => {
+      connectionRoomRequired: (room) => {
         return api.i18n.localize('actionhero.errors.connectionRoomRequired')
       },
     }
diff --git a/examples/custom-server-actionhero/config/i18n.js b/examples/custom-server-actionhero/config/i18n.js
index 49ecd6c614..c0bb5daf44 100644
--- a/examples/custom-server-actionhero/config/i18n.js
+++ b/examples/custom-server-actionhero/config/i18n.js
@@ -1,5 +1,5 @@
 exports['default'] = {
-  i18n: api => {
+  i18n: (api) => {
     return {
       // visit https://github.com/mashpie/i18n-node to see all configuration options
       // locale path can be configired from within ./config/api.js
@@ -28,7 +28,7 @@ exports['default'] = {
 }
 
 exports.test = {
-  i18n: api => {
+  i18n: (api) => {
     return {
       updateFiles: true,
     }
diff --git a/examples/custom-server-actionhero/config/logger.js b/examples/custom-server-actionhero/config/logger.js
index db9018a2be..5740c6bfaa 100644
--- a/examples/custom-server-actionhero/config/logger.js
+++ b/examples/custom-server-actionhero/config/logger.js
@@ -2,16 +2,16 @@ const fs = require('fs')
 const cluster = require('cluster')
 
 exports['default'] = {
-  logger: api => {
+  logger: (api) => {
     let logger = { transports: [] }
 
     // console logger
     if (cluster.isMaster) {
-      logger.transports.push(function(api, winston) {
+      logger.transports.push(function (api, winston) {
         return new winston.transports.Console({
           colorize: true,
           level: 'info',
-          timestamp: function() {
+          timestamp: function () {
             return api.id + ' @ ' + new Date().toISOString()
           },
         })
@@ -19,7 +19,7 @@ exports['default'] = {
     }
 
     // file logger
-    logger.transports.push(function(api, winston) {
+    logger.transports.push(function (api, winston) {
       if (api.config.general.paths.log.length === 1) {
         const logDirectory = api.config.general.paths.log[0]
         try {
@@ -35,7 +35,7 @@ exports['default'] = {
         filename:
           api.config.general.paths.log[0] + '/' + api.pids.title + '.log',
         level: 'info',
-        timestamp: function() {
+        timestamp: function () {
           return api.id + ' @ ' + new Date().toISOString()
         },
       })
@@ -55,7 +55,7 @@ exports['default'] = {
 }
 
 exports.test = {
-  logger: api => {
+  logger: (api) => {
     return {
       transports: null,
     }
diff --git a/examples/custom-server-actionhero/config/plugins.js b/examples/custom-server-actionhero/config/plugins.js
index 6b7c9b1c59..09aae2955c 100644
--- a/examples/custom-server-actionhero/config/plugins.js
+++ b/examples/custom-server-actionhero/config/plugins.js
@@ -1,5 +1,5 @@
 exports['default'] = {
-  plugins: api => {
+  plugins: (api) => {
     /*
     If you want to use plugins in your application, include them here:
 
diff --git a/examples/custom-server-actionhero/config/redis.js b/examples/custom-server-actionhero/config/redis.js
index 3e7da36baa..a5ace1cbed 100644
--- a/examples/custom-server-actionhero/config/redis.js
+++ b/examples/custom-server-actionhero/config/redis.js
@@ -11,7 +11,7 @@ if (process.env.REDIS_URL) {
 }
 
 exports['default'] = {
-  redis: api => {
+  redis: (api) => {
     // konstructor: The redis client constructor method.  All redis methods must be promises
     // args: The arguments to pass to the constructor
     // buildNew: is it `new konstructor()` or just `konstructor()`?
diff --git a/examples/custom-server-actionhero/config/routes.js b/examples/custom-server-actionhero/config/routes.js
index 717e9948bf..3999d268a5 100644
--- a/examples/custom-server-actionhero/config/routes.js
+++ b/examples/custom-server-actionhero/config/routes.js
@@ -1,5 +1,5 @@
 exports['default'] = {
-  routes: api => {
+  routes: (api) => {
     return {
       get: [{ path: '/', matchTrailingPathParts: true, action: 'render' }],
     }
diff --git a/examples/custom-server-actionhero/config/servers/socket.js b/examples/custom-server-actionhero/config/servers/socket.js
index dbc74d2b71..d3b43a8a59 100644
--- a/examples/custom-server-actionhero/config/servers/socket.js
+++ b/examples/custom-server-actionhero/config/servers/socket.js
@@ -1,6 +1,6 @@
 exports['default'] = {
   servers: {
-    socket: api => {
+    socket: (api) => {
       return {
         enabled: process.env.ENABLE_TCP_SERVER !== undefined,
         // TCP or TLS?
@@ -24,7 +24,7 @@ exports['default'] = {
 
 exports.test = {
   servers: {
-    socket: api => {
+    socket: (api) => {
       return {
         enabled: true,
         port: 1001 + (process.pid % 64535),
diff --git a/examples/custom-server-actionhero/config/servers/web.js b/examples/custom-server-actionhero/config/servers/web.js
index 08d2e4fe10..366377985b 100644
--- a/examples/custom-server-actionhero/config/servers/web.js
+++ b/examples/custom-server-actionhero/config/servers/web.js
@@ -2,7 +2,7 @@ const os = require('os')
 
 exports['default'] = {
   servers: {
-    web: api => {
+    web: (api) => {
       return {
         enabled: true,
         // HTTP or HTTPS?
@@ -93,7 +93,7 @@ exports['default'] = {
 
 exports.production = {
   servers: {
-    web: api => {
+    web: (api) => {
       return {
         padding: null,
         metadataOptions: {
@@ -107,7 +107,7 @@ exports.production = {
 
 exports.test = {
   servers: {
-    web: api => {
+    web: (api) => {
       return {
         secure: false,
         port: process.env.PORT || 1000 + (process.pid % 64535),
diff --git a/examples/custom-server-actionhero/config/servers/websocket.js b/examples/custom-server-actionhero/config/servers/websocket.js
index fb159ef0b0..182808619b 100644
--- a/examples/custom-server-actionhero/config/servers/websocket.js
+++ b/examples/custom-server-actionhero/config/servers/websocket.js
@@ -2,7 +2,7 @@
 
 exports['default'] = {
   servers: {
-    websocket: api => {
+    websocket: (api) => {
       return {
         enabled: true,
         // you can pass a FQDN (string) here or 'window.location.origin'
@@ -53,7 +53,7 @@ exports['default'] = {
 
 exports['test'] = {
   servers: {
-    websocket: api => {
+    websocket: (api) => {
       return { clientUrl: null }
     },
   },
diff --git a/examples/custom-server-actionhero/config/tasks.js b/examples/custom-server-actionhero/config/tasks.js
index c2b7a55f9a..1fdecb0aef 100644
--- a/examples/custom-server-actionhero/config/tasks.js
+++ b/examples/custom-server-actionhero/config/tasks.js
@@ -1,5 +1,5 @@
 exports['default'] = {
-  tasks: api => {
+  tasks: (api) => {
     return {
       // Should this node run a scheduler to promote delayed tasks?
       scheduler: false,
@@ -52,7 +52,7 @@ exports['default'] = {
 }
 
 exports.test = {
-  tasks: api => {
+  tasks: (api) => {
     return {
       timeout: 100,
       checkTimeout: 50,
diff --git a/examples/custom-server-actionhero/initializers/next.js b/examples/custom-server-actionhero/initializers/next.js
index a352fb78a5..7d24aa6155 100644
--- a/examples/custom-server-actionhero/initializers/next.js
+++ b/examples/custom-server-actionhero/initializers/next.js
@@ -9,7 +9,7 @@ module.exports = class NextInitializer extends Initializer {
 
   async initialize() {
     api.next = {
-      render: async connection => {
+      render: async (connection) => {
         if (connection.type !== 'web') {
           throw new Error('Connections for NEXT apps must be of type "web"')
         }
diff --git a/examples/custom-server-express/server.js b/examples/custom-server-express/server.js
index f5f4ac2026..d29a2b1f2c 100644
--- a/examples/custom-server-express/server.js
+++ b/examples/custom-server-express/server.js
@@ -21,7 +21,7 @@ app.prepare().then(() => {
     return handle(req, res)
   })
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/custom-server-fastify/server.js b/examples/custom-server-fastify/server.js
index 29e5049695..7eae77d652 100644
--- a/examples/custom-server-fastify/server.js
+++ b/examples/custom-server-fastify/server.js
@@ -44,10 +44,10 @@ fastify.register((fastify, opts, next) => {
 
       next()
     })
-    .catch(err => next(err))
+    .catch((err) => next(err))
 })
 
-fastify.listen(port, err => {
+fastify.listen(port, (err) => {
   if (err) throw err
   console.log(`> Ready on http://localhost:${port}`)
 })
diff --git a/examples/custom-server-hapi/next-wrapper.js b/examples/custom-server-hapi/next-wrapper.js
index 072a694512..864b957b81 100644
--- a/examples/custom-server-hapi/next-wrapper.js
+++ b/examples/custom-server-hapi/next-wrapper.js
@@ -1,11 +1,14 @@
-const nextHandlerWrapper = app => {
+const nextHandlerWrapper = (app) => {
   const handler = app.getRequestHandler()
   return async ({ raw, url }, h) => {
     await handler(raw.req, raw.res, url)
     return h.close
   }
 }
-const defaultHandlerWrapper = app => async ({ raw: { req, res }, url }, h) => {
+const defaultHandlerWrapper = (app) => async (
+  { raw: { req, res }, url },
+  h
+) => {
   const { pathname, query } = url
   const html = await app.renderToHTML(req, res, pathname, query)
   return h.response(html).code(res.statusCode)
diff --git a/examples/custom-server-koa/server.js b/examples/custom-server-koa/server.js
index 20ee2c0159..238fddbb13 100644
--- a/examples/custom-server-koa/server.js
+++ b/examples/custom-server-koa/server.js
@@ -11,17 +11,17 @@ app.prepare().then(() => {
   const server = new Koa()
   const router = new Router()
 
-  router.get('/a', async ctx => {
+  router.get('/a', async (ctx) => {
     await app.render(ctx.req, ctx.res, '/a', ctx.query)
     ctx.respond = false
   })
 
-  router.get('/b', async ctx => {
+  router.get('/b', async (ctx) => {
     await app.render(ctx.req, ctx.res, '/b', ctx.query)
     ctx.respond = false
   })
 
-  router.all('*', async ctx => {
+  router.all('*', async (ctx) => {
     await handle(ctx.req, ctx.res)
     ctx.respond = false
   })
diff --git a/examples/custom-server-polka/server.js b/examples/custom-server-polka/server.js
index c16380ccf0..95ef44b2bb 100644
--- a/examples/custom-server-polka/server.js
+++ b/examples/custom-server-polka/server.js
@@ -15,7 +15,7 @@ app.prepare().then(() => {
 
   server.all('*', (req, res) => handle(req, res))
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/custom-server/server.js b/examples/custom-server/server.js
index 442184f5c6..1ab3cd0283 100644
--- a/examples/custom-server/server.js
+++ b/examples/custom-server/server.js
@@ -18,7 +18,7 @@ app.prepare().then(() => {
     } else {
       handle(req, res, parsedUrl)
     }
-  }).listen(port, err => {
+  }).listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/ssr-caching/pages/blog/[id].js b/examples/ssr-caching/pages/blog/[id].js
index 44606a200e..eca5dcb51d 100644
--- a/examples/ssr-caching/pages/blog/[id].js
+++ b/examples/ssr-caching/pages/blog/[id].js
@@ -1,6 +1,6 @@
 import React from 'react'
 
-export default function(props) {
+export default function (props) {
   return (
     <div>
       <h1>My {props.id} blog post</h1>
diff --git a/examples/ssr-caching/server.js b/examples/ssr-caching/server.js
index 0fc217c8f4..6e309cab3d 100644
--- a/examples/ssr-caching/server.js
+++ b/examples/ssr-caching/server.js
@@ -38,7 +38,7 @@ app.prepare().then(() => {
 
   server.get('*', (req, res) => handle(req, res))
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/using-router/components/Header.js b/examples/using-router/components/Header.js
index 0c2299dff4..3de6f707ea 100644
--- a/examples/using-router/components/Header.js
+++ b/examples/using-router/components/Header.js
@@ -12,7 +12,7 @@ const Link = ({ children, href }) => {
   return (
     <a
       href="#"
-      onClick={e => {
+      onClick={(e) => {
         e.preventDefault()
         // typically you want to use `next/link` for this usecase
         // but this example shows how you can also access the router
diff --git a/examples/with-algolia-react-instantsearch/components/head.js b/examples/with-algolia-react-instantsearch/components/head.js
index e93e8d205b..59c6ef9b3e 100644
--- a/examples/with-algolia-react-instantsearch/components/head.js
+++ b/examples/with-algolia-react-instantsearch/components/head.js
@@ -6,7 +6,7 @@ const defaultDescription = ''
 const defaultOGURL = ''
 const defaultOGImage = ''
 
-export const Head = props => (
+export const Head = (props) => (
   <NextHead>
     <meta charSet="UTF-8" />
     <title>{props.title || ''}</title>
diff --git a/examples/with-algolia-react-instantsearch/next.config.js b/examples/with-algolia-react-instantsearch/next.config.js
index 671b8a880a..f960da5587 100644
--- a/examples/with-algolia-react-instantsearch/next.config.js
+++ b/examples/with-algolia-react-instantsearch/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: config => {
+  webpack: (config) => {
     // Fixes npm packages that depend on `fs` module
     config.node = {
       fs: 'empty',
diff --git a/examples/with-algolia-react-instantsearch/pages/index.js b/examples/with-algolia-react-instantsearch/pages/index.js
index 1d4def7574..1436be772d 100644
--- a/examples/with-algolia-react-instantsearch/pages/index.js
+++ b/examples/with-algolia-react-instantsearch/pages/index.js
@@ -6,7 +6,7 @@ import qs from 'qs'
 
 const updateAfter = 700
 
-const searchStateToUrl = searchState =>
+const searchStateToUrl = (searchState) =>
   searchState ? `${window.location.pathname}?${qs.stringify(searchState)}` : ''
 
 export default class extends React.Component {
@@ -33,7 +33,7 @@ export default class extends React.Component {
     return { resultsState, searchState }
   }
 
-  onSearchStateChange = searchState => {
+  onSearchStateChange = (searchState) => {
     clearTimeout(this.debouncedSetState)
     this.debouncedSetState = setTimeout(() => {
       const href = searchStateToUrl(searchState)
diff --git a/examples/with-ant-design/next.config.js b/examples/with-ant-design/next.config.js
index c98c6c7791..8188ce8128 100644
--- a/examples/with-ant-design/next.config.js
+++ b/examples/with-ant-design/next.config.js
@@ -1,4 +1,4 @@
-const compose = plugins => ({
+const compose = (plugins) => ({
   webpack(config, options) {
     return plugins.reduce((config, plugin) => {
       if (plugin instanceof Array) {
diff --git a/examples/with-apollo-and-redux/components/Clock.js b/examples/with-apollo-and-redux/components/Clock.js
index 4b478bf8a2..3f73635344 100644
--- a/examples/with-apollo-and-redux/components/Clock.js
+++ b/examples/with-apollo-and-redux/components/Clock.js
@@ -2,7 +2,7 @@ import { useSelector, shallowEqual } from 'react-redux'
 
 const useClock = () => {
   return useSelector(
-    state => ({
+    (state) => ({
       lastUpdate: state.lastUpdate,
       light: state.light,
     }),
@@ -10,7 +10,7 @@ const useClock = () => {
   )
 }
 
-const formatTime = time => {
+const formatTime = (time) => {
   // cut off except hh:mm:ss
   return new Date(time).toJSON().slice(11, 19)
 }
diff --git a/examples/with-apollo-and-redux/components/Counter.js b/examples/with-apollo-and-redux/components/Counter.js
index f2a06cca36..12cecc8861 100644
--- a/examples/with-apollo-and-redux/components/Counter.js
+++ b/examples/with-apollo-and-redux/components/Counter.js
@@ -1,7 +1,7 @@
 import { useSelector, useDispatch } from 'react-redux'
 
 const useCounter = () => {
-  const count = useSelector(state => state.count)
+  const count = useSelector((state) => state.count)
   const dispatch = useDispatch()
   const increment = () =>
     dispatch({
diff --git a/examples/with-apollo-and-redux/components/Submit.js b/examples/with-apollo-and-redux/components/Submit.js
index 0ff8f3887d..3fe13bd420 100644
--- a/examples/with-apollo-and-redux/components/Submit.js
+++ b/examples/with-apollo-and-redux/components/Submit.js
@@ -17,7 +17,7 @@ const CREATE_POST_MUTATION = gql`
 const Submit = () => {
   const [createPost, { loading }] = useMutation(CREATE_POST_MUTATION)
 
-  const handleSubmit = event => {
+  const handleSubmit = (event) => {
     event.preventDefault()
     const form = event.target
     const formData = new window.FormData(form)
diff --git a/examples/with-apollo-and-redux/lib/apollo.js b/examples/with-apollo-and-redux/lib/apollo.js
index b36f2cc2ae..d5ce5ace22 100644
--- a/examples/with-apollo-and-redux/lib/apollo.js
+++ b/examples/with-apollo-and-redux/lib/apollo.js
@@ -37,7 +37,7 @@ export function withApollo(PageComponent, { ssr = true } = {}) {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithApollo.getInitialProps = async ctx => {
+    WithApollo.getInitialProps = async (ctx) => {
       const { AppTree } = ctx
 
       // Initialize ApolloClient, add it to the ctx object so
diff --git a/examples/with-apollo-and-redux/lib/redux.js b/examples/with-apollo-and-redux/lib/redux.js
index 55587190b6..00c5f09a55 100644
--- a/examples/with-apollo-and-redux/lib/redux.js
+++ b/examples/with-apollo-and-redux/lib/redux.js
@@ -30,7 +30,7 @@ export const withRedux = (PageComponent, { ssr = true } = {}) => {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithRedux.getInitialProps = async context => {
+    WithRedux.getInitialProps = async (context) => {
       // Get or Create the store with `undefined` as initialState
       // This allows you to set a custom default initialState
       const reduxStore = getOrInitializeStore()
@@ -56,7 +56,7 @@ export const withRedux = (PageComponent, { ssr = true } = {}) => {
 }
 
 let reduxStore
-const getOrInitializeStore = initialState => {
+const getOrInitializeStore = (initialState) => {
   // Always make a new store if server, otherwise state is shared between requests
   if (typeof window === 'undefined') {
     return initializeStore(initialState)
diff --git a/examples/with-apollo/components/Submit.js b/examples/with-apollo/components/Submit.js
index 4d779577ec..1ca9352bf7 100644
--- a/examples/with-apollo/components/Submit.js
+++ b/examples/with-apollo/components/Submit.js
@@ -17,7 +17,7 @@ const CREATE_POST_MUTATION = gql`
 export default function Submit() {
   const [createPost, { loading }] = useMutation(CREATE_POST_MUTATION)
 
-  const handleSubmit = event => {
+  const handleSubmit = (event) => {
     event.preventDefault()
     const form = event.target
     const formData = new window.FormData(form)
diff --git a/examples/with-apollo/lib/apollo.js b/examples/with-apollo/lib/apollo.js
index 484591c62e..9294339cc7 100644
--- a/examples/with-apollo/lib/apollo.js
+++ b/examples/with-apollo/lib/apollo.js
@@ -13,7 +13,7 @@ let globalApolloClient = null
  * inside getStaticProps, getStaticPaths or getServerSideProps
  * @param {NextPageContext | NextAppContext} ctx
  */
-export const initOnContext = ctx => {
+export const initOnContext = (ctx) => {
   const inAppContext = Boolean(ctx.ctx)
 
   // We consider installing `withApollo({ ssr: true })` on global App level
@@ -78,7 +78,7 @@ const initApolloClient = (initialState, ctx) => {
  * @param  {Boolean} [withApolloOptions.ssr=false]
  * @returns {(PageComponent: ReactNode) => ReactNode}
  */
-export const withApollo = ({ ssr = false } = {}) => PageComponent => {
+export const withApollo = ({ ssr = false } = {}) => (PageComponent) => {
   const WithApollo = ({ apolloClient, apolloState, ...pageProps }) => {
     let client
     if (apolloClient) {
@@ -104,7 +104,7 @@ export const withApollo = ({ ssr = false } = {}) => PageComponent => {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithApollo.getInitialProps = async ctx => {
+    WithApollo.getInitialProps = async (ctx) => {
       const inAppContext = Boolean(ctx.ctx)
       const { apolloClient } = initOnContext(ctx)
 
diff --git a/examples/with-apollo/pages/client-only.js b/examples/with-apollo/pages/client-only.js
index 445e956d8d..86045b36ed 100644
--- a/examples/with-apollo/pages/client-only.js
+++ b/examples/with-apollo/pages/client-only.js
@@ -5,7 +5,7 @@ import Submit from '../components/Submit'
 import PostList from '../components/PostList'
 import { withApollo } from '../lib/apollo'
 
-const ClientOnlyPage = props => (
+const ClientOnlyPage = (props) => (
   <App>
     <Header />
     <InfoBox>
diff --git a/examples/with-astroturf/next.config.js b/examples/with-astroturf/next.config.js
index 0ab5ea323d..5bd75ab6cc 100644
--- a/examples/with-astroturf/next.config.js
+++ b/examples/with-astroturf/next.config.js
@@ -2,7 +2,7 @@ const withCSS = require('@zeit/next-css')
 
 module.exports = withCSS({
   cssModules: true,
-  webpack: config => {
+  webpack: (config) => {
     config.module.rules.push({
       test: /\.js$/,
       use: ['astroturf/loader'],
diff --git a/examples/with-atlaskit/pages/_document.js b/examples/with-atlaskit/pages/_document.js
index d43c7f5095..2a59afeb93 100644
--- a/examples/with-atlaskit/pages/_document.js
+++ b/examples/with-atlaskit/pages/_document.js
@@ -9,7 +9,8 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+          enhanceApp: (App) => (props) =>
+            sheet.collectStyles(<App {...props} />),
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-aws-amplify-typescript/pages/index.tsx b/examples/with-aws-amplify-typescript/pages/index.tsx
index 5326ca7904..b09c26b34a 100644
--- a/examples/with-aws-amplify-typescript/pages/index.tsx
+++ b/examples/with-aws-amplify-typescript/pages/index.tsx
@@ -46,24 +46,24 @@ type Action =
 const reducer: React.Reducer<State, Action> = (state, action) => {
   switch (action.type) {
     case 'add-todo': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.todos.push(action.payload)
       })
     }
     case 'delete-todo': {
       const index = state.todos.findIndex(({ id }) => action.payload === id)
       if (index === -1) return state
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.todos.splice(index, 1)
       })
     }
     case 'reset-current': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.currentName = ''
       })
     }
     case 'set-current': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.currentName = action.payload
       })
     }
@@ -111,14 +111,14 @@ const App = (props: Props) => {
     <div>
       <h3>Add a Todo</h3>
       <form
-        onSubmit={ev => {
+        onSubmit={(ev) => {
           ev.preventDefault()
           createToDo(dispatch, state.currentName)
         }}
       >
         <input
           value={state.currentName}
-          onChange={e => {
+          onChange={(e) => {
             dispatch({ type: 'set-current', payload: e.target.value })
           }}
         />
diff --git a/examples/with-aws-amplify-typescript/pages/todo/[id].tsx b/examples/with-aws-amplify-typescript/pages/todo/[id].tsx
index bb77874f10..1e7b58bb88 100644
--- a/examples/with-aws-amplify-typescript/pages/todo/[id].tsx
+++ b/examples/with-aws-amplify-typescript/pages/todo/[id].tsx
@@ -16,7 +16,7 @@ const TodoPage = (props: { todo: GetTodoQuery['getTodo'] }) => {
   )
 }
 
-TodoPage.getInitialProps = async context => {
+TodoPage.getInitialProps = async (context) => {
   const { id } = context.query
   try {
     const todo = (await API.graphql({
diff --git a/examples/with-aws-amplify/pages/index.js b/examples/with-aws-amplify/pages/index.js
index 7ae09a9548..e8faa27ab6 100644
--- a/examples/with-aws-amplify/pages/index.js
+++ b/examples/with-aws-amplify/pages/index.js
@@ -17,24 +17,24 @@ API.configure(config)
 const reducer = (state, action) => {
   switch (action.type) {
     case 'add-todo': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.todos.push(action.payload)
       })
     }
     case 'delete-todo': {
       const index = state.todos.findIndex(({ id }) => action.payload === id)
       if (index === -1) return state
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.todos.splice(index, 1)
       })
     }
     case 'reset-current': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.currentName = ''
       })
     }
     case 'set-current': {
-      return produce(state, draft => {
+      return produce(state, (draft) => {
         draft.currentName = action.payload
       })
     }
@@ -73,7 +73,7 @@ const deleteToDo = async (dispatch, id) => {
     console.warn('Error deleting to do ', err)
   }
 }
-const App = props => {
+const App = (props) => {
   const [state, dispatch] = React.useReducer(reducer, {
     todos: props.todos,
     currentName: '',
@@ -82,14 +82,14 @@ const App = props => {
     <div>
       <h3>Add a Todo</h3>
       <form
-        onSubmit={ev => {
+        onSubmit={(ev) => {
           ev.preventDefault()
           createToDo(dispatch, state.currentName)
         }}
       >
         <input
           value={state.currentName}
-          onChange={e => {
+          onChange={(e) => {
             dispatch({ type: 'set-current', payload: e.target.value })
           }}
         />
diff --git a/examples/with-aws-amplify/pages/todo/[id].js b/examples/with-aws-amplify/pages/todo/[id].js
index 24e7c00f65..1c2e07906e 100644
--- a/examples/with-aws-amplify/pages/todo/[id].js
+++ b/examples/with-aws-amplify/pages/todo/[id].js
@@ -6,7 +6,7 @@ import config from '../../src/aws-exports'
 
 API.configure(config)
 
-const TodoPage = props => {
+const TodoPage = (props) => {
   return (
     <div>
       <h2>Individual Todo {props.todo.id}</h2>
@@ -15,7 +15,7 @@ const TodoPage = props => {
   )
 }
 
-TodoPage.getInitialProps = async context => {
+TodoPage.getInitialProps = async (context) => {
   const { id } = context.query
   try {
     const todo = await API.graphql({
diff --git a/examples/with-cerebral/README.md b/examples/with-cerebral/README.md
index 0033797732..e8460c4202 100644
--- a/examples/with-cerebral/README.md
+++ b/examples/with-cerebral/README.md
@@ -23,11 +23,11 @@ function getUser() {
   this.isLoading = true
   ajax
     .get('/user')
-    .then(user => {
+    .then((user) => {
       this.data = user
       this.isLoading = false
     })
-    .catch(error => {
+    .catch((error) => {
       this.error = error
       this.isLoading = false
     })
diff --git a/examples/with-cerebral/components/Clock.js b/examples/with-cerebral/components/Clock.js
index c821ed3604..20da008b3c 100644
--- a/examples/with-cerebral/components/Clock.js
+++ b/examples/with-cerebral/components/Clock.js
@@ -1,4 +1,4 @@
-export default props => {
+export default (props) => {
   return (
     <div className={props.light ? 'light' : ''}>
       {format(new Date(props.lastUpdate))}
@@ -19,7 +19,7 @@ export default props => {
   )
 }
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
diff --git a/examples/with-cerebral/modules/clock/provider.js b/examples/with-cerebral/modules/clock/provider.js
index 32056db921..65dd58fe78 100644
--- a/examples/with-cerebral/modules/clock/provider.js
+++ b/examples/with-cerebral/modules/clock/provider.js
@@ -2,7 +2,7 @@
 const SECOND = 1000
 let timer = null
 
-export default context => {
+export default (context) => {
   context.clock = {
     start(signalPath) {
       const signal = context.controller.getSignal(signalPath)
diff --git a/examples/with-chakra-ui/src/components/Container.js b/examples/with-chakra-ui/src/components/Container.js
index 71a00de1e8..3d41c1c331 100644
--- a/examples/with-chakra-ui/src/components/Container.js
+++ b/examples/with-chakra-ui/src/components/Container.js
@@ -1,7 +1,7 @@
 import React from 'react'
 import { Flex, useColorMode } from '@chakra-ui/core'
 
-export const Container = props => {
+export const Container = (props) => {
   const { colorMode } = useColorMode()
 
   const bgColor = { light: 'gray.50', dark: 'gray.900' }
diff --git a/examples/with-chakra-ui/src/components/Footer.js b/examples/with-chakra-ui/src/components/Footer.js
index f9a127bae5..84810a52be 100644
--- a/examples/with-chakra-ui/src/components/Footer.js
+++ b/examples/with-chakra-ui/src/components/Footer.js
@@ -1,3 +1,3 @@
 import { Flex } from '@chakra-ui/core'
 
-export const Footer = props => <Flex as="footer" py="8rem" {...props} />
+export const Footer = (props) => <Flex as="footer" py="8rem" {...props} />
diff --git a/examples/with-chakra-ui/src/components/Main.js b/examples/with-chakra-ui/src/components/Main.js
index 1152088c9a..ad88b27666 100644
--- a/examples/with-chakra-ui/src/components/Main.js
+++ b/examples/with-chakra-ui/src/components/Main.js
@@ -1,6 +1,6 @@
 import { Stack } from '@chakra-ui/core'
 
-export const Main = props => (
+export const Main = (props) => (
   <Stack
     spacing="1.5rem"
     width="100%"
diff --git a/examples/with-context-api/pages/about.js b/examples/with-context-api/pages/about.js
index 58576e6e77..481c9c0481 100644
--- a/examples/with-context-api/pages/about.js
+++ b/examples/with-context-api/pages/about.js
@@ -5,11 +5,11 @@ const AboutPage = () => {
   const count = useCount()
   const dispatch = useDispatchCount()
 
-  const handleIncrease = event =>
+  const handleIncrease = (event) =>
     dispatch({
       type: 'INCREASE',
     })
-  const handleIncrease15 = event =>
+  const handleIncrease15 = (event) =>
     dispatch({
       type: 'INCREASE_BY',
       payload: 15,
diff --git a/examples/with-context-api/pages/index.js b/examples/with-context-api/pages/index.js
index 5f74e0ef14..7e26a78c30 100644
--- a/examples/with-context-api/pages/index.js
+++ b/examples/with-context-api/pages/index.js
@@ -5,11 +5,11 @@ const IndexPage = () => {
   const count = useCount()
   const dispatch = useDispatchCount()
 
-  const handleIncrease = event =>
+  const handleIncrease = (event) =>
     dispatch({
       type: 'INCREASE',
     })
-  const handleDecrease = event =>
+  const handleDecrease = (event) =>
     dispatch({
       type: 'DECREASE',
     })
diff --git a/examples/with-cookie-auth-fauna/components/header.js b/examples/with-cookie-auth-fauna/components/header.js
index 2cb89ca060..42408b448e 100644
--- a/examples/with-cookie-auth-fauna/components/header.js
+++ b/examples/with-cookie-auth-fauna/components/header.js
@@ -1,7 +1,7 @@
 import Link from 'next/link'
 import { logout } from '../utils/auth'
 
-const Header = props => (
+const Header = (props) => (
   <header>
     <nav>
       <ul>
diff --git a/examples/with-cookie-auth-fauna/components/layout.js b/examples/with-cookie-auth-fauna/components/layout.js
index 8442a255f7..df1a6f134e 100644
--- a/examples/with-cookie-auth-fauna/components/layout.js
+++ b/examples/with-cookie-auth-fauna/components/layout.js
@@ -1,7 +1,7 @@
 import Head from 'next/head'
 import Header from './header'
 
-const Layout = props => (
+const Layout = (props) => (
   <>
     <Head>
       <title>With Cookies</title>
diff --git a/examples/with-cookie-auth-fauna/pages/api/profile.js b/examples/with-cookie-auth-fauna/pages/api/profile.js
index 4f1510930b..2d5ef16108 100644
--- a/examples/with-cookie-auth-fauna/pages/api/profile.js
+++ b/examples/with-cookie-auth-fauna/pages/api/profile.js
@@ -2,7 +2,7 @@ import { query as q } from 'faunadb'
 import cookie from 'cookie'
 import { faunaClient, FAUNA_SECRET_COOKIE } from '../../utils/fauna-auth'
 
-export const profileApi = async faunaSecret => {
+export const profileApi = async (faunaSecret) => {
   const ref = await faunaClient(faunaSecret).query(q.Identity())
   return ref.id
 }
diff --git a/examples/with-cookie-auth-fauna/pages/login.js b/examples/with-cookie-auth-fauna/pages/login.js
index accf2cd5ae..eef8136f93 100644
--- a/examples/with-cookie-auth-fauna/pages/login.js
+++ b/examples/with-cookie-auth-fauna/pages/login.js
@@ -49,7 +49,7 @@ function Login() {
             id="email"
             name="email"
             value={userData.email}
-            onChange={event =>
+            onChange={(event) =>
               setUserData(
                 Object.assign({}, userData, { email: event.target.value })
               )
@@ -62,7 +62,7 @@ function Login() {
             id="password"
             name="password"
             value={userData.password}
-            onChange={event =>
+            onChange={(event) =>
               setUserData(
                 Object.assign({}, userData, { password: event.target.value })
               )
diff --git a/examples/with-cookie-auth-fauna/pages/profile.js b/examples/with-cookie-auth-fauna/pages/profile.js
index 2295b58494..6d7269702e 100644
--- a/examples/with-cookie-auth-fauna/pages/profile.js
+++ b/examples/with-cookie-auth-fauna/pages/profile.js
@@ -5,7 +5,7 @@ import { FAUNA_SECRET_COOKIE } from '../utils/fauna-auth'
 import { profileApi } from './api/profile'
 import Layout from '../components/layout'
 
-const Profile = props => {
+const Profile = (props) => {
   const { userId } = props
 
   return (
@@ -21,7 +21,7 @@ const Profile = props => {
   )
 }
 
-Profile.getInitialProps = async ctx => {
+Profile.getInitialProps = async (ctx) => {
   if (typeof window === 'undefined') {
     const { req, res } = ctx
     const cookies = cookie.parse(req.headers.cookie ?? '')
diff --git a/examples/with-cookie-auth-fauna/pages/signup.js b/examples/with-cookie-auth-fauna/pages/signup.js
index 302c7dabef..f278efcf95 100644
--- a/examples/with-cookie-auth-fauna/pages/signup.js
+++ b/examples/with-cookie-auth-fauna/pages/signup.js
@@ -45,7 +45,7 @@ function Signup() {
             id="email"
             name="email"
             value={userData.email}
-            onChange={event =>
+            onChange={(event) =>
               setUserData(
                 Object.assign({}, userData, { email: event.target.value })
               )
@@ -58,7 +58,7 @@ function Signup() {
             id="password"
             name="password"
             value={userData.password}
-            onChange={event =>
+            onChange={(event) =>
               setUserData(
                 Object.assign({}, userData, { password: event.target.value })
               )
diff --git a/examples/with-cookie-auth-fauna/utils/auth.js b/examples/with-cookie-auth-fauna/utils/auth.js
index a7a2c95135..7e72a1dddc 100644
--- a/examples/with-cookie-auth-fauna/utils/auth.js
+++ b/examples/with-cookie-auth-fauna/utils/auth.js
@@ -13,9 +13,9 @@ export const logout = async () => {
   Router.push('/login')
 }
 
-export const withAuthSync = Component => {
-  const Wrapper = props => {
-    const syncLogout = event => {
+export const withAuthSync = (Component) => {
+  const Wrapper = (props) => {
+    const syncLogout = (event) => {
       if (event.key === 'logout') {
         console.log('logged out from storage!')
         Router.push('/login')
diff --git a/examples/with-cookie-auth-fauna/utils/fauna-auth.js b/examples/with-cookie-auth-fauna/utils/fauna-auth.js
index 85ff891deb..d8f7abedd5 100644
--- a/examples/with-cookie-auth-fauna/utils/fauna-auth.js
+++ b/examples/with-cookie-auth-fauna/utils/fauna-auth.js
@@ -8,12 +8,12 @@ export const serverClient = new faunadb.Client({
 })
 
 // Used for any authed requests.
-export const faunaClient = secret =>
+export const faunaClient = (secret) =>
   new faunadb.Client({
     secret,
   })
 
-export const serializeFaunaCookie = userSecret => {
+export const serializeFaunaCookie = (userSecret) => {
   const cookieSerialized = cookie.serialize(FAUNA_SECRET_COOKIE, userSecret, {
     sameSite: 'lax',
     secure: process.env.NODE_ENV === 'production',
diff --git a/examples/with-custom-reverse-proxy/pages/index.js b/examples/with-custom-reverse-proxy/pages/index.js
index 5435dcb128..9c01f77fea 100644
--- a/examples/with-custom-reverse-proxy/pages/index.js
+++ b/examples/with-custom-reverse-proxy/pages/index.js
@@ -2,7 +2,7 @@ import { useState, useEffect } from 'react'
 import { useRouter } from 'next/router'
 import useSWR from 'swr'
 
-const fetcher = url => fetch(url).then(res => res.json())
+const fetcher = (url) => fetch(url).then((res) => res.json())
 
 const useMounted = () => {
   const [mounted, setMounted] = useState(false)
diff --git a/examples/with-custom-reverse-proxy/server.js b/examples/with-custom-reverse-proxy/server.js
index 411bd70d97..dfaf6f4487 100644
--- a/examples/with-custom-reverse-proxy/server.js
+++ b/examples/with-custom-reverse-proxy/server.js
@@ -29,7 +29,7 @@ app
     // Set up the proxy.
     if (dev && devProxy) {
       const proxyMiddleware = require('http-proxy-middleware')
-      Object.keys(devProxy).forEach(function(context) {
+      Object.keys(devProxy).forEach(function (context) {
         server.use(proxyMiddleware(context, devProxy[context]))
       })
     }
@@ -37,14 +37,14 @@ app
     // Default catch-all handler to allow Next.js to handle all other routes
     server.all('*', (req, res) => handle(req, res))
 
-    server.listen(port, err => {
+    server.listen(port, (err) => {
       if (err) {
         throw err
       }
       console.log(`> Ready on port ${port} [${env}]`)
     })
   })
-  .catch(err => {
+  .catch((err) => {
     console.log('An error occurred, unable to start the server')
     console.log(err)
   })
diff --git a/examples/with-draft-js/pages/index.js b/examples/with-draft-js/pages/index.js
index e7c367f246..6d71c3a3bb 100644
--- a/examples/with-draft-js/pages/index.js
+++ b/examples/with-draft-js/pages/index.js
@@ -34,7 +34,7 @@ export default class App extends React.Component {
     }
 
     this.focus = () => this.editor.focus()
-    this.onChange = editorState => this.setState({ editorState })
+    this.onChange = (editorState) => this.setState({ editorState })
   }
 
   onClickEditor = () => {
@@ -60,10 +60,7 @@ export default class App extends React.Component {
 
   // 2- Identify the selection coordinates
   setSelectionXY = () => {
-    var r = window
-      .getSelection()
-      .getRangeAt(0)
-      .getBoundingClientRect()
+    var r = window.getSelection().getRangeAt(0).getBoundingClientRect()
     var relative = document.body.parentNode.getBoundingClientRect()
     // 2-a Set the selection coordinates in the state
     this.setState(
@@ -149,7 +146,7 @@ export default class App extends React.Component {
     })
   }
 
-  handleKeyCommand = command => {
+  handleKeyCommand = (command) => {
     const { editorState } = this.state
     const newState = RichUtils.handleKeyCommand(editorState, command)
     if (newState) {
@@ -159,7 +156,7 @@ export default class App extends React.Component {
     return false
   }
 
-  toggleToolbar = inlineStyle => {
+  toggleToolbar = (inlineStyle) => {
     this.onChange(
       RichUtils.toggleInlineStyle(this.state.editorState, inlineStyle)
     )
@@ -187,7 +184,7 @@ export default class App extends React.Component {
     return (
       <div>
         <div
-          ref={elem => {
+          ref={(elem) => {
             this.elemWidth = elem ? elem.clientWidth : 0
             this.elemHeight = elem ? elem.clientHeight : 0
           }}
@@ -204,7 +201,7 @@ export default class App extends React.Component {
             placeholder="Tell a story..."
             editorKey="foobar"
             spellCheck={false}
-            ref={element => {
+            ref={(element) => {
               this.editor = element
             }}
           />
@@ -246,7 +243,7 @@ const styleMap = {
 class ToolbarButton extends React.Component {
   constructor() {
     super()
-    this.onToggle = e => {
+    this.onToggle = (e) => {
       e.preventDefault()
       this.props.onToggle(this.props.style)
     }
@@ -272,11 +269,11 @@ var toolbarItems = [
   { label: 'Surprise', style: 'ANYCUSTOMSTYLE' },
 ]
 
-const ToolBar = props => {
+const ToolBar = (props) => {
   var currentStyle = props.editorState.getCurrentInlineStyle()
   return (
     <div>
-      {toolbarItems.map(toolbarItem => (
+      {toolbarItems.map((toolbarItem) => (
         <ToolbarButton
           key={toolbarItem.label}
           active={currentStyle.has(toolbarItem.style)}
diff --git a/examples/with-electron-typescript/electron-src/electron-next.d.ts b/examples/with-electron-typescript/electron-src/electron-next.d.ts
index 04323b02b0..d12b291ece 100644
--- a/examples/with-electron-typescript/electron-src/electron-next.d.ts
+++ b/examples/with-electron-typescript/electron-src/electron-next.d.ts
@@ -4,7 +4,7 @@ declare module 'electron-next' {
     development: string
   }
 
-  export default function(
+  export default function (
     directories: Directories | string,
     port?: number
   ): Promise<void>
diff --git a/examples/with-electron-typescript/renderer/components/List.tsx b/examples/with-electron-typescript/renderer/components/List.tsx
index 679951d1ac..83183e7ba0 100644
--- a/examples/with-electron-typescript/renderer/components/List.tsx
+++ b/examples/with-electron-typescript/renderer/components/List.tsx
@@ -8,7 +8,7 @@ type Props = {
 
 const List: React.FunctionComponent<Props> = ({ items }) => (
   <ul>
-    {items.map(item => (
+    {items.map((item) => (
       <li key={item.id}>
         <ListItem data={item} />
       </li>
diff --git a/examples/with-electron-typescript/renderer/utils/sample-api.ts b/examples/with-electron-typescript/renderer/utils/sample-api.ts
index a326dfa976..cbdd8efd30 100644
--- a/examples/with-electron-typescript/renderer/utils/sample-api.ts
+++ b/examples/with-electron-typescript/renderer/utils/sample-api.ts
@@ -14,7 +14,7 @@ export const dataArray: User[] = [
  * Throws an error if not found.
  */
 export async function findData(id: number | string) {
-  const selected = dataArray.find(data => data.id === Number(id))
+  const selected = dataArray.find((data) => data.id === Number(id))
 
   if (!selected) {
     throw new Error('Cannot find user')
diff --git a/examples/with-electron/renderer/pages/index.js b/examples/with-electron/renderer/pages/index.js
index 5dc86a465d..b645f3f5e5 100644
--- a/examples/with-electron/renderer/pages/index.js
+++ b/examples/with-electron/renderer/pages/index.js
@@ -21,11 +21,11 @@ export default class extends Component {
     this.setState({ message })
   }
 
-  handleChange = event => {
+  handleChange = (event) => {
     this.setState({ input: event.target.value })
   }
 
-  handleSubmit = event => {
+  handleSubmit = (event) => {
     event.preventDefault()
     global.ipcRenderer.send('message', this.state.input)
     this.setState({ message: null })
diff --git a/examples/with-emotion-11/shared/styles.js b/examples/with-emotion-11/shared/styles.js
index 98c80f719d..9fca859055 100644
--- a/examples/with-emotion-11/shared/styles.js
+++ b/examples/with-emotion-11/shared/styles.js
@@ -63,5 +63,5 @@ export const Animated = styled('div')`
   & code {
     background-color: linen;
   }
-  animation: ${props => props.animation} 0.2s infinite ease-in-out alternate;
+  animation: ${(props) => props.animation} 0.2s infinite ease-in-out alternate;
 `
diff --git a/examples/with-emotion/shared/styles.js b/examples/with-emotion/shared/styles.js
index eb1879bf70..1a5a404776 100644
--- a/examples/with-emotion/shared/styles.js
+++ b/examples/with-emotion/shared/styles.js
@@ -63,5 +63,5 @@ export const Animated = styled('div')`
   & code {
     background-color: linen;
   }
-  animation: ${props => props.animation} 0.2s infinite ease-in-out alternate;
+  animation: ${(props) => props.animation} 0.2s infinite ease-in-out alternate;
 `
diff --git a/examples/with-env-from-next-config-js/next.config.js b/examples/with-env-from-next-config-js/next.config.js
index 26ec9926ff..cf0d96ee31 100644
--- a/examples/with-env-from-next-config-js/next.config.js
+++ b/examples/with-env-from-next-config-js/next.config.js
@@ -4,7 +4,7 @@ const {
 } = require('next/constants')
 
 // This uses phases as outlined here: https://nextjs.org/docs/#custom-configuration
-module.exports = phase => {
+module.exports = (phase) => {
   // when started in development mode `next dev` or `npm run dev` regardless of the value of STAGING environmental variable
   const isDev = phase === PHASE_DEVELOPMENT_SERVER
   // when `next build` or `npm run build` is used
diff --git a/examples/with-fela/pages/_document.js b/examples/with-fela/pages/_document.js
index 32f8ec8bc5..7eb6061ac7 100755
--- a/examples/with-fela/pages/_document.js
+++ b/examples/with-fela/pages/_document.js
@@ -10,7 +10,7 @@ export default class MyDocument extends Document {
 
     ctx.renderPage = () =>
       originalRenderPage({
-        enhanceApp: App => props => <App {...props} renderer={renderer} />,
+        enhanceApp: (App) => (props) => <App {...props} renderer={renderer} />,
       })
 
     const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-firebase-authentication/pages/_document.js b/examples/with-firebase-authentication/pages/_document.js
index cd6898a473..ebe5447f8d 100644
--- a/examples/with-firebase-authentication/pages/_document.js
+++ b/examples/with-firebase-authentication/pages/_document.js
@@ -32,7 +32,7 @@ class CustomDocument extends Document {
   }
 }
 
-CustomDocument.getInitialProps = async ctx => {
+CustomDocument.getInitialProps = async (ctx) => {
   // Get the AuthUserInfo object. This is set if the server-rendered page
   // is wrapped in the `withAuthUser` higher-order component.
   const AuthUserInfo = get(ctx, 'myCustomData.AuthUserInfo', null)
diff --git a/examples/with-firebase-authentication/pages/api/login.js b/examples/with-firebase-authentication/pages/api/login.js
index 4e0b9992ab..dad83c08f9 100644
--- a/examples/with-firebase-authentication/pages/api/login.js
+++ b/examples/with-firebase-authentication/pages/api/login.js
@@ -21,15 +21,15 @@ const handler = (req, res) => {
   // it's possible Firebase's `verifySessionCookie` will make frequent network
   // requests in a serverless context.
   return verifyIdToken(token)
-    .then(decodedToken => {
+    .then((decodedToken) => {
       req.session.decodedToken = decodedToken
       req.session.token = token
       return decodedToken
     })
-    .then(decodedToken => {
+    .then((decodedToken) => {
       return res.status(200).json({ status: true, decodedToken })
     })
-    .catch(error => {
+    .catch((error) => {
       return res.status(500).json({ error })
     })
 }
diff --git a/examples/with-firebase-authentication/pages/example.js b/examples/with-firebase-authentication/pages/example.js
index c643f9ca0c..866f452bf1 100644
--- a/examples/with-firebase-authentication/pages/example.js
+++ b/examples/with-firebase-authentication/pages/example.js
@@ -1,7 +1,7 @@
 import React from 'react'
 import Link from 'next/link'
 
-const Example = props => {
+const Example = (props) => {
   return (
     <div>
       <p>
diff --git a/examples/with-firebase-authentication/pages/index.js b/examples/with-firebase-authentication/pages/index.js
index b917e57561..69211f8a5c 100644
--- a/examples/with-firebase-authentication/pages/index.js
+++ b/examples/with-firebase-authentication/pages/index.js
@@ -7,7 +7,7 @@ import withAuthUser from '../utils/pageWrappers/withAuthUser'
 import withAuthUserInfo from '../utils/pageWrappers/withAuthUserInfo'
 import logout from '../utils/auth/logout'
 
-const Index = props => {
+const Index = (props) => {
   const { AuthUserInfo, data } = props
   const AuthUser = get(AuthUserInfo, 'AuthUser', null)
   const { favoriteFood } = data
@@ -58,7 +58,7 @@ const Index = props => {
 }
 
 // Just an example.
-const mockFetchData = async userId => ({
+const mockFetchData = async (userId) => ({
   user: {
     ...(userId && {
       id: userId,
@@ -67,7 +67,7 @@ const mockFetchData = async userId => ({
   favoriteFood: 'pizza',
 })
 
-Index.getInitialProps = async ctx => {
+Index.getInitialProps = async (ctx) => {
   // Get the AuthUserInfo object. This is set in `withAuthUser.js`.
   // The AuthUserInfo object is available on both the server and client.
   const AuthUserInfo = get(ctx, 'myCustomData.AuthUserInfo', null)
diff --git a/examples/with-firebase-authentication/utils/auth/firebaseAdmin.js b/examples/with-firebase-authentication/utils/auth/firebaseAdmin.js
index 89b13bb527..c2c8cf6610 100644
--- a/examples/with-firebase-authentication/utils/auth/firebaseAdmin.js
+++ b/examples/with-firebase-authentication/utils/auth/firebaseAdmin.js
@@ -1,6 +1,6 @@
 import * as admin from 'firebase-admin'
 
-export const verifyIdToken = token => {
+export const verifyIdToken = (token) => {
   const firebasePrivateKey = process.env.FIREBASE_PRIVATE_KEY
 
   if (!admin.apps.length) {
@@ -18,7 +18,7 @@ export const verifyIdToken = token => {
   return admin
     .auth()
     .verifyIdToken(token)
-    .catch(error => {
+    .catch((error) => {
       throw error
     })
 }
diff --git a/examples/with-firebase-authentication/utils/auth/firebaseSessionHandler.js b/examples/with-firebase-authentication/utils/auth/firebaseSessionHandler.js
index dce481ff34..cb1f3f87b3 100644
--- a/examples/with-firebase-authentication/utils/auth/firebaseSessionHandler.js
+++ b/examples/with-firebase-authentication/utils/auth/firebaseSessionHandler.js
@@ -1,10 +1,10 @@
 // From:
 // https://github.com/zeit/next.js/blob/canary/examples/with-firebase-authentication/pages/index.js
 
-export const setSession = user => {
+export const setSession = (user) => {
   // Log in.
   if (user) {
-    return user.getIdToken().then(token => {
+    return user.getIdToken().then((token) => {
       return fetch('/api/login', {
         method: 'POST',
         // eslint-disable-next-line no-undef
diff --git a/examples/with-firebase-authentication/utils/auth/logout.js b/examples/with-firebase-authentication/utils/auth/logout.js
index 9e64e7239b..f113d0ef30 100644
--- a/examples/with-firebase-authentication/utils/auth/logout.js
+++ b/examples/with-firebase-authentication/utils/auth/logout.js
@@ -20,7 +20,7 @@ export default async () => {
       }
       return true
     })
-    .catch(e => {
+    .catch((e) => {
       console.error(e)
       return false
     })
diff --git a/examples/with-firebase-authentication/utils/auth/user.js b/examples/with-firebase-authentication/utils/auth/user.js
index e143d08035..a6be82ce04 100644
--- a/examples/with-firebase-authentication/utils/auth/user.js
+++ b/examples/with-firebase-authentication/utils/auth/user.js
@@ -10,7 +10,7 @@ import { get, has } from 'lodash/object'
  * @return {String} AuthUser.email - The user's email
  * @return {Boolean} AuthUser.emailVerified - Whether the user has verified their email
  */
-export const createAuthUser = firebaseUser => {
+export const createAuthUser = (firebaseUser) => {
   if (!firebaseUser || !firebaseUser.uid) {
     return null
   }
diff --git a/examples/with-firebase-authentication/utils/middleware/commonMiddleware.js b/examples/with-firebase-authentication/utils/middleware/commonMiddleware.js
index 59c7a1d0a9..17f1de3d90 100644
--- a/examples/with-firebase-authentication/utils/middleware/commonMiddleware.js
+++ b/examples/with-firebase-authentication/utils/middleware/commonMiddleware.js
@@ -1,4 +1,4 @@
 import cookieSession from './cookieSession'
 import cookieSessionRefresh from './cookieSessionRefresh'
 
-export default handler => cookieSession(cookieSessionRefresh(handler))
+export default (handler) => cookieSession(cookieSessionRefresh(handler))
diff --git a/examples/with-firebase-authentication/utils/middleware/cookieSession.js b/examples/with-firebase-authentication/utils/middleware/cookieSession.js
index 44e2334624..01f5cf14a0 100644
--- a/examples/with-firebase-authentication/utils/middleware/cookieSession.js
+++ b/examples/with-firebase-authentication/utils/middleware/cookieSession.js
@@ -31,7 +31,7 @@ export const addSession = (req, res) => {
   includeSession(req, res, () => {})
 }
 
-export default handler => (req, res) => {
+export default (handler) => (req, res) => {
   try {
     addSession(req, res)
   } catch (e) {
diff --git a/examples/with-firebase-authentication/utils/middleware/cookieSessionRefresh.js b/examples/with-firebase-authentication/utils/middleware/cookieSessionRefresh.js
index 27109a78d0..9ff904d391 100644
--- a/examples/with-firebase-authentication/utils/middleware/cookieSessionRefresh.js
+++ b/examples/with-firebase-authentication/utils/middleware/cookieSessionRefresh.js
@@ -1,7 +1,7 @@
 // Update a value in the cookie so that the set-cookie will be sent.
 // Only changes every minute so that it's not sent with every request.
 // https://github.com/expressjs/cookie-session#extending-the-session-expiration
-export default handler => (req, res) => {
+export default (handler) => (req, res) => {
   if (req.session) {
     req.session.nowInMinutes = Math.floor(Date.now() / 60e3)
   }
diff --git a/examples/with-firebase-authentication/utils/pageWrappers/withAuthUser.js b/examples/with-firebase-authentication/utils/pageWrappers/withAuthUser.js
index 305642a8f1..7bb343aa64 100644
--- a/examples/with-firebase-authentication/utils/pageWrappers/withAuthUser.js
+++ b/examples/with-firebase-authentication/utils/pageWrappers/withAuthUser.js
@@ -9,8 +9,8 @@ import { createAuthUser, createAuthUserInfo } from '../auth/user'
 // Gets the authenticated user from the Firebase JS SDK, when client-side,
 // or from the request object, when server-side. Add the AuthUserInfo to
 // context.
-export default ComposedComponent => {
-  const WithAuthUserComp = props => {
+export default (ComposedComponent) => {
+  const WithAuthUserComp = (props) => {
     const { AuthUserInfo, ...otherProps } = props
 
     // We'll use the authed user from client-side auth (Firebase JS SDK)
@@ -29,7 +29,7 @@ export default ComposedComponent => {
     )
   }
 
-  WithAuthUserComp.getInitialProps = async ctx => {
+  WithAuthUserComp.getInitialProps = async (ctx) => {
     const { req, res } = ctx
 
     // Get the AuthUserInfo object.
diff --git a/examples/with-firebase-authentication/utils/pageWrappers/withAuthUserInfo.js b/examples/with-firebase-authentication/utils/pageWrappers/withAuthUserInfo.js
index 5701b5c88d..401807ddcb 100644
--- a/examples/with-firebase-authentication/utils/pageWrappers/withAuthUserInfo.js
+++ b/examples/with-firebase-authentication/utils/pageWrappers/withAuthUserInfo.js
@@ -6,12 +6,12 @@ import { get } from 'lodash/object'
 import { AuthUserInfoContext } from '../auth/hooks'
 
 // Provides an AuthUserInfo prop to the composed component.
-export default ComposedComponent => {
-  const WithAuthUserInfoComp = props => {
+export default (ComposedComponent) => {
+  const WithAuthUserInfoComp = (props) => {
     const { AuthUserInfo: AuthUserInfoFromSession, ...otherProps } = props
     return (
       <AuthUserInfoContext.Consumer>
-        {AuthUserInfo => (
+        {(AuthUserInfo) => (
           <ComposedComponent
             {...otherProps}
             AuthUserInfo={AuthUserInfo || AuthUserInfoFromSession}
@@ -21,7 +21,7 @@ export default ComposedComponent => {
     )
   }
 
-  WithAuthUserInfoComp.getInitialProps = async ctx => {
+  WithAuthUserInfoComp.getInitialProps = async (ctx) => {
     const AuthUserInfo = get(ctx, 'myCustomData.AuthUserInfo', null)
 
     // Evaluate the composed component's getInitialProps().
diff --git a/examples/with-firebase-cloud-messaging/server.js b/examples/with-firebase-cloud-messaging/server.js
index 5caff65ee3..12eb993dbc 100644
--- a/examples/with-firebase-cloud-messaging/server.js
+++ b/examples/with-firebase-cloud-messaging/server.js
@@ -34,7 +34,7 @@ app.prepare().then(() => {
     return handle(req, res)
   })
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/with-firebase-cloud-messaging/utils/webPush.js b/examples/with-firebase-cloud-messaging/utils/webPush.js
index 185a569b29..78177ee211 100644
--- a/examples/with-firebase-cloud-messaging/utils/webPush.js
+++ b/examples/with-firebase-cloud-messaging/utils/webPush.js
@@ -7,7 +7,7 @@ const firebaseCloudMessaging = {
     return localforage.getItem('fcm_token')
   },
 
-  init: async function() {
+  init: async function () {
     firebase.initializeApp({
       apiKey: 'YOUR-API-KEY',
       projectId: 'YOUR-PROJECT-ID',
diff --git a/examples/with-firebase/context/userContext.js b/examples/with-firebase/context/userContext.js
index dd82753f87..23f6f216c6 100644
--- a/examples/with-firebase/context/userContext.js
+++ b/examples/with-firebase/context/userContext.js
@@ -9,7 +9,7 @@ export default ({ children }) => {
 
   useEffect(() => {
     // Listen authenticated user
-    const unsubscriber = firebase.auth().onAuthStateChanged(async user => {
+    const unsubscriber = firebase.auth().onAuthStateChanged(async (user) => {
       try {
         if (user) {
           // User is signed in.
diff --git a/examples/with-google-analytics-amp/components/amp/AmpAnalytics.js b/examples/with-google-analytics-amp/components/amp/AmpAnalytics.js
index cfd7580be5..4c6c7183e3 100644
--- a/examples/with-google-analytics-amp/components/amp/AmpAnalytics.js
+++ b/examples/with-google-analytics-amp/components/amp/AmpAnalytics.js
@@ -2,7 +2,7 @@ import React from 'react'
 
 import AmpIncludeCustomElement from './AmpIncludeCustomElement'
 
-export default props => (
+export default (props) => (
   <>
     <AmpIncludeCustomElement name="amp-analytics" version="0.1" />
     <amp-analytics type={props.type}>
diff --git a/examples/with-google-analytics-amp/components/amp/AmpIncludeCustomElement.js b/examples/with-google-analytics-amp/components/amp/AmpIncludeCustomElement.js
index 6fa77501ad..b313087f9b 100644
--- a/examples/with-google-analytics-amp/components/amp/AmpIncludeCustomElement.js
+++ b/examples/with-google-analytics-amp/components/amp/AmpIncludeCustomElement.js
@@ -1,7 +1,7 @@
 import React from 'react'
 import Head from 'next/head'
 
-export default props => (
+export default (props) => (
   <Head>
     <script
       async
diff --git a/examples/with-google-analytics-amp/lib/gtag.js b/examples/with-google-analytics-amp/lib/gtag.js
index af7227c959..3ea8bf79c3 100644
--- a/examples/with-google-analytics-amp/lib/gtag.js
+++ b/examples/with-google-analytics-amp/lib/gtag.js
@@ -1,7 +1,7 @@
 export const GA_TRACKING_ID = '<YOUR_GA_TRACKING_ID>'
 
 // https://developers.google.com/analytics/devguides/collection/gtagjs/pages
-export const pageview = url => {
+export const pageview = (url) => {
   window.gtag('config', GA_TRACKING_ID, {
     page_path: url,
   })
diff --git a/examples/with-google-analytics-amp/pages/_app.js b/examples/with-google-analytics-amp/pages/_app.js
index 3232451a83..ff43bf82b5 100644
--- a/examples/with-google-analytics-amp/pages/_app.js
+++ b/examples/with-google-analytics-amp/pages/_app.js
@@ -3,6 +3,6 @@ import Router from 'next/router'
 
 import * as gtag from '../lib/gtag'
 
-Router.events.on('routeChangeComplete', url => gtag.pageview(url))
+Router.events.on('routeChangeComplete', (url) => gtag.pageview(url))
 
 export default App
diff --git a/examples/with-google-analytics-amp/pages/contact.js b/examples/with-google-analytics-amp/pages/contact.js
index 6b43aa833c..419e8d9a6d 100644
--- a/examples/with-google-analytics-amp/pages/contact.js
+++ b/examples/with-google-analytics-amp/pages/contact.js
@@ -6,11 +6,11 @@ import * as gtag from '../lib/gtag'
 export default class extends Component {
   state = { message: '' }
 
-  handleInput = e => {
+  handleInput = (e) => {
     this.setState({ message: e.target.value })
   }
 
-  handleSubmit = e => {
+  handleSubmit = (e) => {
     e.preventDefault()
 
     gtag.event({
diff --git a/examples/with-google-analytics/lib/gtag.js b/examples/with-google-analytics/lib/gtag.js
index af7227c959..3ea8bf79c3 100644
--- a/examples/with-google-analytics/lib/gtag.js
+++ b/examples/with-google-analytics/lib/gtag.js
@@ -1,7 +1,7 @@
 export const GA_TRACKING_ID = '<YOUR_GA_TRACKING_ID>'
 
 // https://developers.google.com/analytics/devguides/collection/gtagjs/pages
-export const pageview = url => {
+export const pageview = (url) => {
   window.gtag('config', GA_TRACKING_ID, {
     page_path: url,
   })
diff --git a/examples/with-google-analytics/pages/_app.js b/examples/with-google-analytics/pages/_app.js
index 3232451a83..ff43bf82b5 100644
--- a/examples/with-google-analytics/pages/_app.js
+++ b/examples/with-google-analytics/pages/_app.js
@@ -3,6 +3,6 @@ import Router from 'next/router'
 
 import * as gtag from '../lib/gtag'
 
-Router.events.on('routeChangeComplete', url => gtag.pageview(url))
+Router.events.on('routeChangeComplete', (url) => gtag.pageview(url))
 
 export default App
diff --git a/examples/with-google-analytics/pages/contact.js b/examples/with-google-analytics/pages/contact.js
index 6b43aa833c..419e8d9a6d 100644
--- a/examples/with-google-analytics/pages/contact.js
+++ b/examples/with-google-analytics/pages/contact.js
@@ -6,11 +6,11 @@ import * as gtag from '../lib/gtag'
 export default class extends Component {
   state = { message: '' }
 
-  handleInput = e => {
+  handleInput = (e) => {
     this.setState({ message: e.target.value })
   }
 
-  handleSubmit = e => {
+  handleSubmit = (e) => {
     e.preventDefault()
 
     gtag.event({
diff --git a/examples/with-graphql-faunadb/components/Footer.js b/examples/with-graphql-faunadb/components/Footer.js
index b71c3de37b..63e0e0908f 100644
--- a/examples/with-graphql-faunadb/components/Footer.js
+++ b/examples/with-graphql-faunadb/components/Footer.js
@@ -8,7 +8,7 @@ import {
   footerColumnListURL,
 } from '../styles/footer.js'
 
-export default props => (
+export default (props) => (
   <footer className={footer.className}>
     <div className={footerContent.className}>
       <div
diff --git a/examples/with-graphql-faunadb/components/GuestbookEntry.js b/examples/with-graphql-faunadb/components/GuestbookEntry.js
index 02120bb01d..71dd93522e 100644
--- a/examples/with-graphql-faunadb/components/GuestbookEntry.js
+++ b/examples/with-graphql-faunadb/components/GuestbookEntry.js
@@ -12,7 +12,7 @@ import {
   guestbookEntryShareTwitterButtonLogo2,
 } from '../styles/guestbookentry'
 
-export default props => (
+export default (props) => (
   <>
     <div className={guestbookEntry.className}>
       <div className={guestbookEntryUserDetail.className}>
diff --git a/examples/with-graphql-faunadb/components/Header.js b/examples/with-graphql-faunadb/components/Header.js
index b5ba165fa4..3b8925a9e9 100644
--- a/examples/with-graphql-faunadb/components/Header.js
+++ b/examples/with-graphql-faunadb/components/Header.js
@@ -1,6 +1,6 @@
 import { headerBanner, headerTitle } from '../styles/header'
 
-export default props => (
+export default (props) => (
   <>
     <a href="https://fauna.com" target="_blank" rel="noopener noreferrer">
       <img
diff --git a/examples/with-graphql-faunadb/components/Hero.js b/examples/with-graphql-faunadb/components/Hero.js
index 0fa9fb02f1..14361209a2 100644
--- a/examples/with-graphql-faunadb/components/Hero.js
+++ b/examples/with-graphql-faunadb/components/Hero.js
@@ -18,7 +18,7 @@ function getEntries(data) {
   return data ? data.entries.data.reverse() : []
 }
 
-export default props => {
+export default (props) => {
   const { data, errorMessage } = useGuestbookEntries()
   const [entries, setEntries] = useState([])
   const [twitterHandle, setTwitterHandle] = useState('')
@@ -43,14 +43,14 @@ export default props => {
     }
     setSubmitting(true)
     createGuestbookEntry(twitterHandle, story)
-      .then(data => {
+      .then((data) => {
         entries.unshift(data.data.createGuestbookEntry)
         setTwitterHandle('')
         setStory('')
         setEntries(entries)
         setSubmitting(false)
       })
-      .catch(error => {
+      .catch((error) => {
         console.log(`boo :( ${error}`)
         alert('🤷‍♀️')
         setSubmitting(false)
diff --git a/examples/with-graphql-faunadb/pages/index.js b/examples/with-graphql-faunadb/pages/index.js
index 7e1321c810..847ae7e382 100644
--- a/examples/with-graphql-faunadb/pages/index.js
+++ b/examples/with-graphql-faunadb/pages/index.js
@@ -2,7 +2,7 @@ import Head from 'next/head'
 import Footer from '../components/Footer'
 import Hero from '../components/Hero'
 
-const Guestbook = props => {
+const Guestbook = (props) => {
   return (
     <>
       <Head>
diff --git a/examples/with-graphql-faunadb/scripts/setup.js b/examples/with-graphql-faunadb/scripts/setup.js
index 8b1f65045e..517653fb23 100644
--- a/examples/with-graphql-faunadb/scripts/setup.js
+++ b/examples/with-graphql-faunadb/scripts/setup.js
@@ -12,7 +12,7 @@ const readline = require('readline').createInterface({
 })
 
 // In order to set up a database, we need an admin key, so let's ask the user for a key.
-readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
+readline.question(`Please provide the FaunaDB admin key\n`, (adminKey) => {
   // A graphql schema can be imported in override or merge mode: 'https://docs.fauna.com/fauna/current/api/graphql/endpoints#import'
   const options = {
     model: 'merge',
@@ -22,7 +22,7 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
   const stream = fs.createReadStream('./schema.gql').pipe(request.post(options))
 
   streamToPromise(stream)
-    .then(res => {
+    .then((res) => {
       const readableResult = res.toString()
       if (readableResult.startsWith('Invalid authorization header')) {
         console.error('You need to provide a secret, closing. Try again')
@@ -37,11 +37,11 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
         return readline.close()
       }
     })
-    .catch(err => {
+    .catch((err) => {
       console.error(err)
       console.error(`Could not import schema, closing`)
     })
-    .then(res => {
+    .then((res) => {
       // The GraphQL schema is important, this means that we now have a GuestbookEntry Collection and an entries index.
       // Then we create a token that can only read and write to that index and collection
       var client = new faunadb.Client({ secret: adminKey })
@@ -61,12 +61,12 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
             ],
           })
         )
-        .then(res => {
+        .then((res) => {
           console.log(
             '2. Successfully created role to read and write guestbook entries'
           )
         })
-        .catch(err => {
+        .catch((err) => {
           if (err.toString().includes('instance already exists')) {
             console.log('2. Role already exists.')
           } else {
@@ -74,11 +74,11 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
           }
         })
     })
-    .catch(err => {
+    .catch((err) => {
       console.error(err)
       console.error(`Failed to create role, closing`)
     })
-    .then(res => {
+    .then((res) => {
       // The GraphQL schema is important, this means that we now have a GuestbookEntry Collection and an entries index.
       // Then we create a token that can only read and write to that index and collection
       var client = new faunadb.Client({ secret: adminKey })
@@ -88,7 +88,7 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
             role: q.Role('GuestbookRole'),
           })
         )
-        .then(res => {
+        .then((res) => {
           console.log('3. Created key to use in client')
           console.log(
             'Replace the < GRAPHQL_SECRET > placehold in next.config.js with:'
@@ -96,7 +96,7 @@ readline.question(`Please provide the FaunaDB admin key\n`, adminKey => {
           console.log(res.secret)
         })
     })
-    .catch(err => {
+    .catch((err) => {
       console.error(err)
       console.error(`Failed to create key, closing`)
     })
diff --git a/examples/with-graphql-hooks/components/submit.js b/examples/with-graphql-hooks/components/submit.js
index 3b391fd8e4..71e7fb8395 100644
--- a/examples/with-graphql-hooks/components/submit.js
+++ b/examples/with-graphql-hooks/components/submit.js
@@ -16,7 +16,7 @@ export default function Submit({ onSubmission }) {
   const [createPost, state] = useMutation(CREATE_POST)
 
   return (
-    <form onSubmit={event => handleSubmit(event, onSubmission, createPost)}>
+    <form onSubmit={(event) => handleSubmit(event, onSubmission, createPost)}>
       <h1>Submit</h1>
       <input placeholder="title" name="title" type="text" required />
       <input placeholder="url" name="url" type="url" required />
diff --git a/examples/with-graphql-hooks/lib/with-graphql-client.js b/examples/with-graphql-hooks/lib/with-graphql-client.js
index b9be751934..a65130b69e 100644
--- a/examples/with-graphql-hooks/lib/with-graphql-client.js
+++ b/examples/with-graphql-hooks/lib/with-graphql-client.js
@@ -3,7 +3,7 @@ import initGraphQL from './init-graphql'
 import Head from 'next/head'
 import { getInitialState } from 'graphql-hooks-ssr'
 
-export default App => {
+export default (App) => {
   return class GraphQLHooks extends React.Component {
     static displayName = 'GraphQLHooks(App)'
     static async getInitialProps(ctx) {
diff --git a/examples/with-grommet/pages/_document.js b/examples/with-grommet/pages/_document.js
index d43c7f5095..2a59afeb93 100644
--- a/examples/with-grommet/pages/_document.js
+++ b/examples/with-grommet/pages/_document.js
@@ -9,7 +9,8 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+          enhanceApp: (App) => (props) =>
+            sheet.collectStyles(<App {...props} />),
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-http2/server.js b/examples/with-http2/server.js
index ee872d61b1..5ec52af1a7 100644
--- a/examples/with-http2/server.js
+++ b/examples/with-http2/server.js
@@ -16,7 +16,7 @@ const server = http2.createSecureServer({
 })
 
 app.prepare().then(() => {
-  server.on('error', err => console.error(err))
+  server.on('error', (err) => console.error(err))
 
   // Process the various routes based on `req`
   // `/`      -> Render index.js
diff --git a/examples/with-i18n-rosetta/lib/i18n.js b/examples/with-i18n-rosetta/lib/i18n.js
index 6353c0d6a4..be7f3fa08a 100644
--- a/examples/with-i18n-rosetta/lib/i18n.js
+++ b/examples/with-i18n-rosetta/lib/i18n.js
@@ -32,7 +32,7 @@ export default function I18n({ children, locale, lngDict }) {
       i18n.set(locale, activeDict)
       activeLocaleRef.current = locale
       // force rerender
-      setTick(tick => tick + 1)
+      setTick((tick) => tick + 1)
     }
   }, [locale, activeDict])
 
@@ -46,7 +46,7 @@ export default function I18n({ children, locale, lngDict }) {
         i18n.set(l, dict)
         setActiveDict(dict)
       } else {
-        setTick(tick => tick + 1)
+        setTick((tick) => tick + 1)
       }
     },
   }
diff --git a/examples/with-i18n-rosetta/pages/[lng]/index.js b/examples/with-i18n-rosetta/pages/[lng]/index.js
index 0870f5055a..3be9c28225 100644
--- a/examples/with-i18n-rosetta/pages/[lng]/index.js
+++ b/examples/with-i18n-rosetta/pages/[lng]/index.js
@@ -38,7 +38,7 @@ export async function getStaticProps({ params }) {
 
 export async function getStaticPaths() {
   return {
-    paths: languages.map(l => ({ params: { lng: l } })),
+    paths: languages.map((l) => ({ params: { lng: l } })),
     fallback: false,
   }
 }
diff --git a/examples/with-iron-session/components/Header.js b/examples/with-iron-session/components/Header.js
index 1cdfd0219c..2833a3a545 100644
--- a/examples/with-iron-session/components/Header.js
+++ b/examples/with-iron-session/components/Header.js
@@ -41,7 +41,7 @@ const Header = () => {
               <li>
                 <a
                   href="/api/logout"
-                  onClick={async e => {
+                  onClick={async (e) => {
                     e.preventDefault()
                     await mutateUser(fetchJson('/api/logout'))
                     router.push('/login')
diff --git a/examples/with-iron-session/lib/fetchJson.js b/examples/with-iron-session/lib/fetchJson.js
index 0200981411..b2a429b5fd 100644
--- a/examples/with-iron-session/lib/fetchJson.js
+++ b/examples/with-iron-session/lib/fetchJson.js
@@ -1,6 +1,6 @@
 import fetch from 'node-fetch'
 
-export default async function(...args) {
+export default async function (...args) {
   try {
     const response = await fetch(...args)
 
diff --git a/examples/with-iron-session/pages/_app.js b/examples/with-iron-session/pages/_app.js
index b8adf4d59b..c7ea469f3a 100644
--- a/examples/with-iron-session/pages/_app.js
+++ b/examples/with-iron-session/pages/_app.js
@@ -6,7 +6,7 @@ function MyApp({ Component, pageProps }) {
     <SWRConfig
       value={{
         fetcher: fetch,
-        onError: err => {
+        onError: (err) => {
           console.error(err)
         },
       }}
diff --git a/examples/with-iron-session/pages/profile-ssr.js b/examples/with-iron-session/pages/profile-ssr.js
index c548c787ef..d0e20c09a7 100644
--- a/examples/with-iron-session/pages/profile-ssr.js
+++ b/examples/with-iron-session/pages/profile-ssr.js
@@ -32,7 +32,7 @@ const SsrProfile = ({ user }) => {
   )
 }
 
-export const getServerSideProps = withSession(async function({ req, res }) {
+export const getServerSideProps = withSession(async function ({ req, res }) {
   const user = req.session.get('user')
 
   if (user === undefined) {
diff --git a/examples/with-kea/pages/index.js b/examples/with-kea/pages/index.js
index 1b5adc2c61..2803180ebf 100644
--- a/examples/with-kea/pages/index.js
+++ b/examples/with-kea/pages/index.js
@@ -5,8 +5,8 @@ import { kea } from 'kea'
 const logic = kea({
   path: () => ['kea'],
   actions: () => ({
-    increment: amount => ({ amount }),
-    decrement: amount => ({ amount }),
+    increment: (amount) => ({ amount }),
+    decrement: (amount) => ({ amount }),
   }),
   reducers: ({ actions }) => ({
     counter: [
@@ -21,7 +21,7 @@ const logic = kea({
   selectors: ({ selectors }) => ({
     doubleCounter: [
       () => [selectors.counter],
-      counter => counter * 2,
+      (counter) => counter * 2,
       PropTypes.number,
     ],
   }),
diff --git a/examples/with-kea/store.js b/examples/with-kea/store.js
index 36609df136..fc761b3f41 100644
--- a/examples/with-kea/store.js
+++ b/examples/with-kea/store.js
@@ -8,8 +8,8 @@ const reducers = combineReducers({
 const reduxDevTools =
   typeof window !== 'undefined' && window.__REDUX_DEVTOOLS_EXTENSION__
     ? window.__REDUX_DEVTOOLS_EXTENSION__()
-    : f => f
+    : (f) => f
 
-export const initStore = initialState => {
+export const initStore = (initialState) => {
   return createStore(reducers, initialState, compose(reduxDevTools))
 }
diff --git a/examples/with-lingui/components/LangSwitcher.js b/examples/with-lingui/components/LangSwitcher.js
index ba67118ff6..8f9f48fec0 100644
--- a/examples/with-lingui/components/LangSwitcher.js
+++ b/examples/with-lingui/components/LangSwitcher.js
@@ -25,10 +25,10 @@ export default () => {
             key={i18n.language}
             name="lang"
             defaultValue={availableLanguages.find(
-              lang => lang !== i18n.language
+              (lang) => lang !== i18n.language
             )}
           >
-            {availableLanguages.map(lang => (
+            {availableLanguages.map((lang) => (
               <option key={lang} value={lang} disabled={i18n.language === lang}>
                 {i18n._(availableLanguageNames[lang])}
               </option>
diff --git a/examples/with-lingui/components/withLang.js b/examples/with-lingui/components/withLang.js
index 6f6081b462..deba288b2e 100644
--- a/examples/with-lingui/components/withLang.js
+++ b/examples/with-lingui/components/withLang.js
@@ -7,7 +7,7 @@ export default (Component, defaultLang = 'en') =>
       const language = ctx.query.lang || defaultLang
       const [props, catalog] = await Promise.all([
         Component.getInitialProps ? Component.getInitialProps(ctx) : {},
-        import(`../locale/${language}/messages.po`).then(m => m.default),
+        import(`../locale/${language}/messages.po`).then((m) => m.default),
       ])
 
       return {
diff --git a/examples/with-loading/pages/_app.js b/examples/with-loading/pages/_app.js
index ebc5364908..edb59d1190 100644
--- a/examples/with-loading/pages/_app.js
+++ b/examples/with-loading/pages/_app.js
@@ -3,7 +3,7 @@ import Link from 'next/link'
 import Head from 'next/head'
 import NProgress from 'nprogress'
 
-Router.events.on('routeChangeStart', url => {
+Router.events.on('routeChangeStart', (url) => {
   console.log(`Loading: ${url}`)
   NProgress.start()
 })
diff --git a/examples/with-loading/pages/about.js b/examples/with-loading/pages/about.js
index ffa87104a1..cc2cf5297f 100644
--- a/examples/with-loading/pages/about.js
+++ b/examples/with-loading/pages/about.js
@@ -1,7 +1,7 @@
 const AboutPage = () => <p>This is about Next.js!</p>
 
 export async function getServerSideProps() {
-  await new Promise(resolve => {
+  await new Promise((resolve) => {
     setTimeout(resolve, 500)
   })
   return { props: {} }
diff --git a/examples/with-loading/pages/forever.js b/examples/with-loading/pages/forever.js
index f36f4ba4d4..cd4ee9365c 100644
--- a/examples/with-loading/pages/forever.js
+++ b/examples/with-loading/pages/forever.js
@@ -1,7 +1,7 @@
 const ForeverPage = () => <p>This page was rendered for a while!</p>
 
 export async function getServerSideProps() {
-  await new Promise(resolve => {
+  await new Promise((resolve) => {
     setTimeout(resolve, 3000)
   })
   return { props: {} }
diff --git a/examples/with-magic/components/layout.js b/examples/with-magic/components/layout.js
index 9e3c27da18..4c6a1962c2 100644
--- a/examples/with-magic/components/layout.js
+++ b/examples/with-magic/components/layout.js
@@ -1,7 +1,7 @@
 import Head from 'next/head'
 import Header from './header'
 
-const Layout = props => (
+const Layout = (props) => (
   <>
     <Head>
       <title>Magic</title>
diff --git a/examples/with-magic/lib/hooks.js b/examples/with-magic/lib/hooks.js
index 645364466d..f3a6885fbb 100644
--- a/examples/with-magic/lib/hooks.js
+++ b/examples/with-magic/lib/hooks.js
@@ -2,10 +2,10 @@ import { useEffect } from 'react'
 import Router from 'next/router'
 import useSWR from 'swr'
 
-const fetcher = url =>
+const fetcher = (url) =>
   fetch(url)
-    .then(r => r.json())
-    .then(data => {
+    .then((r) => r.json())
+    .then((data) => {
       return { user: data?.user || null }
     })
 
diff --git a/examples/with-mobx-react-lite/components/Clock.js b/examples/with-mobx-react-lite/components/Clock.js
index 04665088cf..9f0799e7cc 100644
--- a/examples/with-mobx-react-lite/components/Clock.js
+++ b/examples/with-mobx-react-lite/components/Clock.js
@@ -19,9 +19,9 @@ function Clock(props) {
   )
 }
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
 
 export default Clock
diff --git a/examples/with-mobx-state-tree-typescript/components/Clock.tsx b/examples/with-mobx-state-tree-typescript/components/Clock.tsx
index 10cd0cf8ff..ddf2dd6c51 100644
--- a/examples/with-mobx-state-tree-typescript/components/Clock.tsx
+++ b/examples/with-mobx-state-tree-typescript/components/Clock.tsx
@@ -1,8 +1,8 @@
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
 
-const Clock = props => {
+const Clock = (props) => {
   const divStyle = {
     backgroundColor: props.light ? '#999' : '#000',
     color: '#82FA58',
diff --git a/examples/with-mobx-state-tree-typescript/store.ts b/examples/with-mobx-state-tree-typescript/store.ts
index e30e00e4f9..45011456f3 100644
--- a/examples/with-mobx-state-tree-typescript/store.ts
+++ b/examples/with-mobx-state-tree-typescript/store.ts
@@ -14,7 +14,7 @@ const Store = types
     lastUpdate: types.Date,
     light: false,
   })
-  .actions(self => {
+  .actions((self) => {
     let timer: any
     const start = () => {
       timer = setInterval(() => {
diff --git a/examples/with-mobx-state-tree/components/Clock.js b/examples/with-mobx-state-tree/components/Clock.js
index c821ed3604..20da008b3c 100644
--- a/examples/with-mobx-state-tree/components/Clock.js
+++ b/examples/with-mobx-state-tree/components/Clock.js
@@ -1,4 +1,4 @@
-export default props => {
+export default (props) => {
   return (
     <div className={props.light ? 'light' : ''}>
       {format(new Date(props.lastUpdate))}
@@ -19,7 +19,7 @@ export default props => {
   )
 }
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
diff --git a/examples/with-mobx-state-tree/store.js b/examples/with-mobx-state-tree/store.js
index 81d22b06dd..879feca16f 100644
--- a/examples/with-mobx-state-tree/store.js
+++ b/examples/with-mobx-state-tree/store.js
@@ -8,7 +8,7 @@ const Store = types
     lastUpdate: types.Date,
     light: false,
   })
-  .actions(self => {
+  .actions((self) => {
     let timer
     function start() {
       timer = setInterval(() => {
diff --git a/examples/with-mobx/components/Clock.js b/examples/with-mobx/components/Clock.js
index 22a443e0f4..73e6b6e2d1 100644
--- a/examples/with-mobx/components/Clock.js
+++ b/examples/with-mobx/components/Clock.js
@@ -1,5 +1,5 @@
 import { observer } from 'mobx-react'
-const Clock = observer(props => {
+const Clock = observer((props) => {
   return (
     <div className={props.light ? 'light' : ''}>
       {props.timeString}
diff --git a/examples/with-mobx/store.js b/examples/with-mobx/store.js
index dbe98c46fe..d9b802b0de 100644
--- a/examples/with-mobx/store.js
+++ b/examples/with-mobx/store.js
@@ -20,8 +20,8 @@ class Store {
   }
 
   @computed get timeString() {
-    const pad = n => (n < 10 ? `0${n}` : n)
-    const format = t =>
+    const pad = (n) => (n < 10 ? `0${n}` : n)
+    const format = (t) =>
       `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(
         t.getUTCSeconds()
       )}`
@@ -30,7 +30,7 @@ class Store {
 
   stop = () => clearInterval(this.timer)
 
-  hydrate = data => {
+  hydrate = (data) => {
     if (!data) return
 
     this.lastUpdate = data.lastUpdate !== null ? data.lastUpdate : Date.now()
diff --git a/examples/with-monaco-editor/next.config.js b/examples/with-monaco-editor/next.config.js
index fee2127a6c..5d320e7b11 100644
--- a/examples/with-monaco-editor/next.config.js
+++ b/examples/with-monaco-editor/next.config.js
@@ -4,7 +4,7 @@ const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin')
 
 module.exports = withCSS(
   withFonts({
-    webpack: config => {
+    webpack: (config) => {
       config.plugins.push(
         new MonacoWebpackPlugin({
           // Add languages as needed...
diff --git a/examples/with-netlify-cms/next.config.js b/examples/with-netlify-cms/next.config.js
index d876725571..1e266830a5 100644
--- a/examples/with-netlify-cms/next.config.js
+++ b/examples/with-netlify-cms/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: configuration => {
+  webpack: (configuration) => {
     configuration.module.rules.push({
       test: /\.md$/,
       use: 'frontmatter-markdown-loader',
diff --git a/examples/with-netlify-cms/pages/blog/index.js b/examples/with-netlify-cms/pages/blog/index.js
index 97b275097d..e97ee715c4 100644
--- a/examples/with-netlify-cms/pages/blog/index.js
+++ b/examples/with-netlify-cms/pages/blog/index.js
@@ -6,10 +6,10 @@ const importBlogPosts = async () => {
   const markdownFiles = require
     .context('../../content/blogPosts', false, /\.md$/)
     .keys()
-    .map(relativePath => relativePath.substring(2))
+    .map((relativePath) => relativePath.substring(2))
 
   return Promise.all(
-    markdownFiles.map(async path => {
+    markdownFiles.map(async (path) => {
       const markdown = await import(`../../content/blogPosts/${path}`)
       return { ...markdown, slug: path.substring(0, path.length - 3) }
     })
@@ -18,7 +18,7 @@ const importBlogPosts = async () => {
 
 const Blog = ({ postsList }) => (
   <Layout>
-    {postsList.map(post => (
+    {postsList.map((post) => (
       <div key={post.slug} className="post">
         <Link href="/blog/post/[slug]" as={`/blog/post/${post.slug}`}>
           <a>
diff --git a/examples/with-netlify-cms/pages/blog/post/[slug].js b/examples/with-netlify-cms/pages/blog/post/[slug].js
index b24c1d9148..8d82ec537e 100644
--- a/examples/with-netlify-cms/pages/blog/post/[slug].js
+++ b/examples/with-netlify-cms/pages/blog/post/[slug].js
@@ -29,7 +29,7 @@ const Post = ({ blogpost }) => {
 export async function getStaticPaths() {
   const paths = fs
     .readdirSync(path.join(process.cwd(), 'content/blogPosts'))
-    .map(blogName => {
+    .map((blogName) => {
       const trimmedName = blogName.substring(0, blogName.length - 3)
       return {
         params: { slug: trimmedName },
diff --git a/examples/with-next-less/style.less b/examples/with-next-less/style.less
index 15cc160d42..8e8957d30d 100644
--- a/examples/with-next-less/style.less
+++ b/examples/with-next-less/style.less
@@ -1,5 +1,5 @@
-@theme: red;
-
-.example {
-  color: @theme;
-}
+@theme: red;
+
+.example {
+  color: @theme;
+}
diff --git a/examples/with-orbit-components/pages/_document.js b/examples/with-orbit-components/pages/_document.js
index d43c7f5095..2a59afeb93 100644
--- a/examples/with-orbit-components/pages/_document.js
+++ b/examples/with-orbit-components/pages/_document.js
@@ -9,7 +9,8 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+          enhanceApp: (App) => (props) =>
+            sheet.collectStyles(<App {...props} />),
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-overmind/components/Items.js b/examples/with-overmind/components/Items.js
index 86d9410c0b..08240c36ba 100644
--- a/examples/with-overmind/components/Items.js
+++ b/examples/with-overmind/components/Items.js
@@ -6,7 +6,7 @@ function Items() {
 
   return (
     <ul>
-      {state.items.map(item => (
+      {state.items.map((item) => (
         <li key={item.id}>{item.title}</li>
       ))}
     </ul>
diff --git a/examples/with-passport-and-next-connect/lib/db.js b/examples/with-passport-and-next-connect/lib/db.js
index 015ffd3572..51ecad5973 100644
--- a/examples/with-passport-and-next-connect/lib/db.js
+++ b/examples/with-passport-and-next-connect/lib/db.js
@@ -12,13 +12,13 @@ export function createUser(req, user) {
 export function findUserByUsername(req, username) {
   // Here you find the user based on id/username in the database
   // const user = await db.findUserById(id)
-  return req.session.users.find(user => user.username === username)
+  return req.session.users.find((user) => user.username === username)
 }
 
 export function updateUserByUsername(req, username, update) {
   // Here you update the user based on id/username in the database
   // const user = await db.updateUserById(id, update)
-  const user = req.session.users.find(u => u.username === username)
+  const user = req.session.users.find((u) => u.username === username)
   Object.assign(user, update)
   return user
 }
@@ -27,6 +27,6 @@ export function deleteUser(req, username) {
   // Here you should delete the user in the database
   // await db.deleteUser(req.user)
   req.session.users = req.session.users.filter(
-    user => user.username !== req.user.username
+    (user) => user.username !== req.user.username
   )
 }
diff --git a/examples/with-passport-and-next-connect/lib/hooks.jsx b/examples/with-passport-and-next-connect/lib/hooks.jsx
index c5bf6cffb2..2fa25a8d2b 100644
--- a/examples/with-passport-and-next-connect/lib/hooks.jsx
+++ b/examples/with-passport-and-next-connect/lib/hooks.jsx
@@ -1,6 +1,6 @@
 import useSWR from 'swr'
 
-export const fetcher = url => fetch(url).then(r => r.json())
+export const fetcher = (url) => fetch(url).then((r) => r.json())
 
 export function useUser() {
   const { data, mutate } = useSWR('/api/user', fetcher)
diff --git a/examples/with-passport-and-next-connect/lib/passport.js b/examples/with-passport-and-next-connect/lib/passport.js
index ad069bd0e1..eade1a163f 100644
--- a/examples/with-passport-and-next-connect/lib/passport.js
+++ b/examples/with-passport-and-next-connect/lib/passport.js
@@ -2,12 +2,12 @@ import passport from 'passport'
 import LocalStrategy from 'passport-local'
 import { findUserByUsername } from './db'
 
-passport.serializeUser(function(user, done) {
+passport.serializeUser(function (user, done) {
   // serialize the username into session
   done(null, user.username)
 })
 
-passport.deserializeUser(function(req, id, done) {
+passport.deserializeUser(function (req, id, done) {
   // deserialize the username back into user object
   const user = findUserByUsername(req, id)
   done(null, user)
diff --git a/examples/with-passport-and-next-connect/pages/api/users.js b/examples/with-passport-and-next-connect/pages/api/users.js
index a20d6c1a20..7ef4d030ac 100644
--- a/examples/with-passport-and-next-connect/pages/api/users.js
+++ b/examples/with-passport-and-next-connect/pages/api/users.js
@@ -26,7 +26,7 @@ handler
     // const hashedPass = await argon2.hash(password);
     // const user = { username, password: hashedPass, name }
     createUser(req, user)
-    req.logIn(user, err => {
+    req.logIn(user, (err) => {
       if (err) throw err
       // Log the signed up user in
       res.status(201).json({
diff --git a/examples/with-passport-and-next-connect/pages/index.js b/examples/with-passport-and-next-connect/pages/index.js
index 5bb5bb0d5e..29fbfd8202 100644
--- a/examples/with-passport-and-next-connect/pages/index.js
+++ b/examples/with-passport-and-next-connect/pages/index.js
@@ -8,7 +8,7 @@ function UserList() {
       <h2>All users</h2>
       {!!users?.length && (
         <ul>
-          {users.map(user => (
+          {users.map((user) => (
             <li key={user.username}>{JSON.stringify(user)}</li>
           ))}
         </ul>
diff --git a/examples/with-passport/components/layout.js b/examples/with-passport/components/layout.js
index 174351ec9b..5456e1ca45 100644
--- a/examples/with-passport/components/layout.js
+++ b/examples/with-passport/components/layout.js
@@ -1,7 +1,7 @@
 import Head from 'next/head'
 import Header from './header'
 
-const Layout = props => (
+const Layout = (props) => (
   <>
     <Head>
       <title>With Cookies</title>
diff --git a/examples/with-passport/lib/hooks.js b/examples/with-passport/lib/hooks.js
index 645364466d..f3a6885fbb 100644
--- a/examples/with-passport/lib/hooks.js
+++ b/examples/with-passport/lib/hooks.js
@@ -2,10 +2,10 @@ import { useEffect } from 'react'
 import Router from 'next/router'
 import useSWR from 'swr'
 
-const fetcher = url =>
+const fetcher = (url) =>
   fetch(url)
-    .then(r => r.json())
-    .then(data => {
+    .then((r) => r.json())
+    .then((data) => {
       return { user: data?.user || null }
     })
 
diff --git a/examples/with-passport/lib/password-local.js b/examples/with-passport/lib/password-local.js
index 1fc07d7d44..fe060b0341 100644
--- a/examples/with-passport/lib/password-local.js
+++ b/examples/with-passport/lib/password-local.js
@@ -1,16 +1,16 @@
 import Local from 'passport-local'
 import { findUser } from './user'
 
-export const localStrategy = new Local.Strategy(function(
+export const localStrategy = new Local.Strategy(function (
   username,
   password,
   done
 ) {
   findUser({ username, password })
-    .then(user => {
+    .then((user) => {
       done(null, user)
     })
-    .catch(error => {
+    .catch((error) => {
       done(error)
     })
 })
diff --git a/examples/with-patternfly/next.config.js b/examples/with-patternfly/next.config.js
index 149294b221..bfdb56619a 100644
--- a/examples/with-patternfly/next.config.js
+++ b/examples/with-patternfly/next.config.js
@@ -46,7 +46,7 @@ module.exports = withCSS(
 
       config.module.rules.push({
         test: /\.svg$/,
-        include: input => input.indexOf('background-filter.svg') > 1,
+        include: (input) => input.indexOf('background-filter.svg') > 1,
         use: [
           {
             loader: 'url-loader',
@@ -64,7 +64,7 @@ module.exports = withCSS(
         test: /\.svg$/,
         // only process SVG modules with this loader if they live under a 'bgimages' directory
         // this is primarily useful when applying a CSS background using an SVG
-        include: input => input.indexOf(BG_IMAGES_DIRNAME) > -1,
+        include: (input) => input.indexOf(BG_IMAGES_DIRNAME) > -1,
         use: {
           loader: 'svg-url-loader',
           options: {},
@@ -75,7 +75,7 @@ module.exports = withCSS(
         test: /\.svg$/,
         // only process SVG modules with this loader when they don't live under a 'bgimages',
         // 'fonts', or 'pficon' directory, those are handled with other loaders
-        include: input =>
+        include: (input) =>
           input.indexOf(BG_IMAGES_DIRNAME) === -1 &&
           input.indexOf('fonts') === -1 &&
           input.indexOf('background-filter') === -1 &&
diff --git a/examples/with-polyfills/next.config.js b/examples/with-polyfills/next.config.js
index 3c845eee6c..5be0529754 100644
--- a/examples/with-polyfills/next.config.js
+++ b/examples/with-polyfills/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: function(cfg) {
+  webpack: function (cfg) {
     const originalEntry = cfg.entry
     cfg.entry = async () => {
       const entries = await originalEntry()
diff --git a/examples/with-portals-ssr/pages/_document.js b/examples/with-portals-ssr/pages/_document.js
index e8b579316e..473b10eecb 100644
--- a/examples/with-portals-ssr/pages/_document.js
+++ b/examples/with-portals-ssr/pages/_document.js
@@ -8,7 +8,8 @@ export default class extends Document {
 
     ctx.renderPage = () =>
       originalRenderPage({
-        enhanceApp: App => props => portals.collectPortals(<App {...props} />),
+        enhanceApp: (App) => (props) =>
+          portals.collectPortals(<App {...props} />),
       })
 
     const { html, ...props } = await Document.getInitialProps(ctx)
diff --git a/examples/with-react-helmet/pages/_document.js b/examples/with-react-helmet/pages/_document.js
index 1a32954380..74be6e6b9d 100644
--- a/examples/with-react-helmet/pages/_document.js
+++ b/examples/with-react-helmet/pages/_document.js
@@ -22,8 +22,8 @@ export default class extends Document {
   // should render on <head>
   get helmetHeadComponents() {
     return Object.keys(this.props.helmet)
-      .filter(el => el !== 'htmlAttributes' && el !== 'bodyAttributes')
-      .map(el => this.props.helmet[el].toComponent())
+      .filter((el) => el !== 'htmlAttributes' && el !== 'bodyAttributes')
+      .map((el) => this.props.helmet[el].toComponent())
   }
 
   render() {
diff --git a/examples/with-react-intl/scripts/extract.js b/examples/with-react-intl/scripts/extract.js
index b491527063..b06975f934 100644
--- a/examples/with-react-intl/scripts/extract.js
+++ b/examples/with-react-intl/scripts/extract.js
@@ -17,8 +17,8 @@ execFileSync('npx', [
 
 const defaultMessages = glob
   .sync('./lang/.messages/**/*.json')
-  .map(filename => readFileSync(filename, 'utf8'))
-  .map(file => JSON.parse(file))
+  .map((filename) => readFileSync(filename, 'utf8'))
+  .map((file) => JSON.parse(file))
   .reduce((messages, descriptors) => {
     descriptors.forEach(({ id, defaultMessage }) => {
       if (messages.hasOwnProperty(id) && messages[id] !== defaultMessage) {
diff --git a/examples/with-react-intl/server.js b/examples/with-react-intl/server.js
index c2874d60f2..73605f543f 100644
--- a/examples/with-react-intl/server.js
+++ b/examples/with-react-intl/server.js
@@ -5,7 +5,7 @@ const areIntlLocalesSupported = require('intl-locales-supported').default
 // Get the supported languages by looking for translations in the `lang/` dir.
 const supportedLanguages = glob
   .sync('./lang/*.json')
-  .map(f => basename(f, '.json'))
+  .map((f) => basename(f, '.json'))
 
 // Polyfill Node with `Intl` that has data for all locales.
 // See: https://formatjs.io/guides/runtime-environments/#server
@@ -49,7 +49,7 @@ const handle = app.getRequestHandler()
 // We need to expose React Intl's locale data on the request for the user's
 // locale. This function will also cache the scripts by lang in memory.
 const localeDataCache = new Map()
-const getLocaleDataScript = locale => {
+const getLocaleDataScript = (locale) => {
   const lang = locale.split('-')[0]
   if (!localeDataCache.has(lang)) {
     const localeDataFile = require.resolve(
@@ -64,7 +64,7 @@ const getLocaleDataScript = locale => {
 // We need to load and expose the translations on the request for the user's
 // locale. These will only be used in production, in dev the `defaultMessage` in
 // each message description in the source code will be used.
-const getMessages = locale => {
+const getMessages = (locale) => {
   return require(`./lang/${locale}.json`)
 }
 
@@ -76,7 +76,7 @@ app.prepare().then(() => {
     req.localeDataScript = getLocaleDataScript(locale)
     req.messages = dev ? {} : getMessages(locale)
     handle(req, res)
-  }).listen(port, err => {
+  }).listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/with-react-jss/pages/_document.js b/examples/with-react-jss/pages/_document.js
index 1afbd0f709..d9069c7284 100644
--- a/examples/with-react-jss/pages/_document.js
+++ b/examples/with-react-jss/pages/_document.js
@@ -9,7 +9,7 @@ export default class JssDocument extends Document {
     const originalRenderPage = ctx.renderPage
     ctx.renderPage = () =>
       originalRenderPage({
-        enhanceApp: App => props => (
+        enhanceApp: (App) => (props) => (
           <JssProvider registry={registry} generateId={generateId}>
             <App {...props} />
           </JssProvider>
diff --git a/examples/with-react-multi-carousel/pages/index.js b/examples/with-react-multi-carousel/pages/index.js
index cfdad8970c..a9a681b270 100644
--- a/examples/with-react-multi-carousel/pages/index.js
+++ b/examples/with-react-multi-carousel/pages/index.js
@@ -4,7 +4,7 @@ import Carousel from 'react-multi-carousel'
 
 import Image from '../components/image'
 
-const styles = theme => ({
+const styles = (theme) => ({
   root: {
     textAlign: 'center',
   },
@@ -58,7 +58,7 @@ class Index extends React.Component {
           itemClass="image-item"
           deviceType={''}
         >
-          {images.map(image => {
+          {images.map((image) => {
             return <Image url={image} alt={image} />
           })}
         </Carousel>
diff --git a/examples/with-react-native-web/next.config.js b/examples/with-react-native-web/next.config.js
index cb7efa4834..0cc8ae53e8 100644
--- a/examples/with-react-native-web/next.config.js
+++ b/examples/with-react-native-web/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: config => {
+  webpack: (config) => {
     config.resolve.alias = {
       ...(config.resolve.alias || {}),
       // Transform all direct `react-native` imports to `react-native-web`
diff --git a/examples/with-react-relay-network-modern/components/BlogPostPreview.js b/examples/with-react-relay-network-modern/components/BlogPostPreview.js
index cbbe280b6d..ed74a0db64 100644
--- a/examples/with-react-relay-network-modern/components/BlogPostPreview.js
+++ b/examples/with-react-relay-network-modern/components/BlogPostPreview.js
@@ -1,7 +1,7 @@
 import React from 'react'
 import { createFragmentContainer, graphql } from 'react-relay'
 
-const BlogPostPreview = props => {
+const BlogPostPreview = (props) => {
   return <div key={props.post.id}>{props.post.title}</div>
 }
 
diff --git a/examples/with-react-relay-network-modern/components/BlogPosts.js b/examples/with-react-relay-network-modern/components/BlogPosts.js
index 30ff74963e..8e5347a424 100644
--- a/examples/with-react-relay-network-modern/components/BlogPosts.js
+++ b/examples/with-react-relay-network-modern/components/BlogPosts.js
@@ -2,7 +2,7 @@ import React from 'react'
 import { createFragmentContainer, graphql } from 'react-relay'
 import BlogPostPreview from './BlogPostPreview'
 
-const BlogPosts = props => {
+const BlogPosts = (props) => {
   return (
     <div>
       <h1>Blog posts</h1>
diff --git a/examples/with-react-relay-network-modern/lib/createEnvironment/client.js b/examples/with-react-relay-network-modern/lib/createEnvironment/client.js
index 356209c9af..7e7953232c 100644
--- a/examples/with-react-relay-network-modern/lib/createEnvironment/client.js
+++ b/examples/with-react-relay-network-modern/lib/createEnvironment/client.js
@@ -10,7 +10,7 @@ let store, source
 let storeEnvironment = null
 
 export default {
-  createEnvironment: records => {
+  createEnvironment: (records) => {
     if (!store) {
       source = new RecordSource(records)
       store = new Store(source)
@@ -25,7 +25,7 @@ export default {
           ttl: 60 * 1000,
         }),
         urlMiddleware({
-          url: req => process.env.RELAY_ENDPOINT,
+          url: (req) => process.env.RELAY_ENDPOINT,
         }),
       ]),
     })
diff --git a/examples/with-react-relay-network-modern/lib/createEnvironment/server.js b/examples/with-react-relay-network-modern/lib/createEnvironment/server.js
index 7d49c52538..ae394fbefd 100644
--- a/examples/with-react-relay-network-modern/lib/createEnvironment/server.js
+++ b/examples/with-react-relay-network-modern/lib/createEnvironment/server.js
@@ -14,13 +14,13 @@ export default {
         store,
         network: new RelayNetworkLayer([
           urlMiddleware({
-            url: req => process.env.RELAY_ENDPOINT,
+            url: (req) => process.env.RELAY_ENDPOINT,
           }),
         ]),
       }),
     }
   },
-  createEnvironment: records => {
+  createEnvironment: (records) => {
     const source = new RecordSource(records)
     const store = new Store(source)
 
@@ -28,7 +28,7 @@ export default {
       store,
       network: new RelayNetworkLayer([
         urlMiddleware({
-          url: req => process.env.RELAY_ENDPOINT,
+          url: (req) => process.env.RELAY_ENDPOINT,
         }),
       ]),
     })
diff --git a/examples/with-react-relay-network-modern/pages/_app.js b/examples/with-react-relay-network-modern/pages/_app.js
index 88254d8906..5615c9295f 100644
--- a/examples/with-react-relay-network-modern/pages/_app.js
+++ b/examples/with-react-relay-network-modern/pages/_app.js
@@ -16,10 +16,7 @@ export default class App extends NextApp {
 
         await fetchQuery(environment, Component.query, variables)
 
-        const records = environment
-          .getStore()
-          .getSource()
-          .toJSON()
+        const records = environment.getStore().getSource().toJSON()
 
         return {
           variables,
diff --git a/examples/with-react-relay-network-modern/schema/init-schema.graphql b/examples/with-react-relay-network-modern/schema/init-schema.graphql
index c7c5711d28..aafc0574a9 100644
--- a/examples/with-react-relay-network-modern/schema/init-schema.graphql
+++ b/examples/with-react-relay-network-modern/schema/init-schema.graphql
@@ -4,4 +4,4 @@ type BlogPost implements Node {
   id: ID! @isUnique
   title: String!
   updatedAt: DateTime!
-}
\ No newline at end of file
+}
diff --git a/examples/with-redux-code-splitting/config/redux.js b/examples/with-redux-code-splitting/config/redux.js
index 0fd14f9234..e752663495 100644
--- a/examples/with-redux-code-splitting/config/redux.js
+++ b/examples/with-redux-code-splitting/config/redux.js
@@ -12,4 +12,4 @@ export const initStore = (initialState = {}) => {
   )
 }
 
-export const reduxPage = comp => withRedux(initStore)(comp)
+export const reduxPage = (comp) => withRedux(initStore)(comp)
diff --git a/examples/with-redux-code-splitting/containers/about.js b/examples/with-redux-code-splitting/containers/about.js
index 86ed9daa9d..97660594d8 100644
--- a/examples/with-redux-code-splitting/containers/about.js
+++ b/examples/with-redux-code-splitting/containers/about.js
@@ -11,7 +11,7 @@ const { actionCreator, getState: getAboutState } = namespaceConfig(
   DEFAULT_STATE
 )
 
-const bumpVersion = actionCreator('bumpVersion', function(state, increment) {
+const bumpVersion = actionCreator('bumpVersion', function (state, increment) {
   return { ...state, version: state.version + increment }
 })
 
@@ -20,7 +20,7 @@ const About = ({ version, bumpVersion }) => (
     <h1>About us</h1>
     <h3>Current version: {version}</h3>
     <p>
-      <button onClick={e => bumpVersion(1)}>Bump version!</button>
+      <button onClick={(e) => bumpVersion(1)}>Bump version!</button>
     </p>
     <Link href="/">
       <a>Homepage</a>
diff --git a/examples/with-redux-code-splitting/containers/homepage.js b/examples/with-redux-code-splitting/containers/homepage.js
index 666e341a56..dc1786461e 100644
--- a/examples/with-redux-code-splitting/containers/homepage.js
+++ b/examples/with-redux-code-splitting/containers/homepage.js
@@ -20,7 +20,7 @@ const Homepage = ({ build, bumpBuild }) => (
     <h1>Homepage</h1>
     <h3>Current build: {build}</h3>
     <p>
-      <button onClick={e => bumpBuild(1)}>Bump build!</button>
+      <button onClick={(e) => bumpBuild(1)}>Bump build!</button>
     </p>
     <Link href="/about">
       <a>About Us</a>
diff --git a/examples/with-redux-observable/components/CharacterInfo.js b/examples/with-redux-observable/components/CharacterInfo.js
index eefd7168af..e2ead714e9 100644
--- a/examples/with-redux-observable/components/CharacterInfo.js
+++ b/examples/with-redux-observable/components/CharacterInfo.js
@@ -37,7 +37,7 @@ const CharacterInfo = ({
   </div>
 )
 
-export default connect(state => ({
+export default connect((state) => ({
   character: state.character,
   error: state.error,
   isFetchedOnServer: state.isFetchedOnServer,
diff --git a/examples/with-redux-observable/redux/epics.js b/examples/with-redux-observable/redux/epics.js
index d32c707e92..7603e63887 100644
--- a/examples/with-redux-observable/redux/epics.js
+++ b/examples/with-redux-observable/redux/epics.js
@@ -9,9 +9,9 @@ import * as types from './actionTypes'
 export const fetchUserEpic = (action$, state$) =>
   action$.pipe(
     ofType(types.START_FETCHING_CHARACTERS),
-    mergeMap(action => {
+    mergeMap((action) => {
       return interval(3000).pipe(
-        map(x => actions.fetchCharacter()),
+        map((x) => actions.fetchCharacter()),
         takeUntil(
           action$.ofType(
             types.STOP_FETCHING_CHARACTERS,
@@ -25,17 +25,17 @@ export const fetchUserEpic = (action$, state$) =>
 export const fetchCharacterEpic = (action$, state$) =>
   action$.pipe(
     ofType(types.FETCH_CHARACTER),
-    mergeMap(action =>
+    mergeMap((action) =>
       request({
         url: `https://swapi.co/api/people/${state$.value.nextCharacterId}`,
       }).pipe(
-        map(response =>
+        map((response) =>
           actions.fetchCharacterSuccess(
             response.response,
             action.payload.isServer
           )
         ),
-        catchError(error =>
+        catchError((error) =>
           of(
             actions.fetchCharacterFailure(
               error.xhr.response,
diff --git a/examples/with-redux-persist/components/clock.js b/examples/with-redux-persist/components/clock.js
index 4e71fc3a92..03506fb5ab 100644
--- a/examples/with-redux-persist/components/clock.js
+++ b/examples/with-redux-persist/components/clock.js
@@ -19,4 +19,4 @@ export default ({ lastUpdate, light }) => {
   )
 }
 
-const format = t => t.toJSON().slice(11, 19) // cut off except hh:mm:ss
+const format = (t) => t.toJSON().slice(11, 19) // cut off except hh:mm:ss
diff --git a/examples/with-redux-persist/components/counter.js b/examples/with-redux-persist/components/counter.js
index cf2eaa17a3..6adef11fe7 100644
--- a/examples/with-redux-persist/components/counter.js
+++ b/examples/with-redux-persist/components/counter.js
@@ -38,7 +38,7 @@ function mapStateToProps(state) {
   const { count } = state
   return { count }
 }
-const mapDispatchToProps = dispatch =>
+const mapDispatchToProps = (dispatch) =>
   bindActionCreators({ incrementCount, decrementCount, resetCount }, dispatch)
 
 export default connect(mapStateToProps, mapDispatchToProps)(Counter)
diff --git a/examples/with-redux-persist/components/data-list.js b/examples/with-redux-persist/components/data-list.js
index 3ad70ac093..43bb9e9742 100644
--- a/examples/with-redux-persist/components/data-list.js
+++ b/examples/with-redux-persist/components/data-list.js
@@ -15,7 +15,7 @@ class DataList extends Component {
     this.setState({ isDataLoading: true })
     window
       .fetch('https://jsonplaceholder.typicode.com/users')
-      .then(function(response) {
+      .then(function (response) {
         if (response.status !== 200) {
           console.log(
             'Looks like there was a problem. Status Code: ' + response.status
@@ -24,12 +24,12 @@ class DataList extends Component {
           self.setState({ isDataLoading: false })
           return
         }
-        response.json().then(function(data) {
+        response.json().then(function (data) {
           loadExampleData(data)
           self.setState({ isDataLoading: false })
         })
       })
-      .catch(function(err) {
+      .catch(function (err) {
         console.log('Fetch Error :-S', err)
         loadingExampleDataFailure()
         self.setState({ isDataLoading: false })
@@ -60,7 +60,7 @@ function mapStateToProps(state) {
   const { exampleData, error } = state
   return { exampleData, error }
 }
-const mapDispatchToProps = dispatch =>
+const mapDispatchToProps = (dispatch) =>
   bindActionCreators({ loadExampleData, loadingExampleDataFailure }, dispatch)
 
 export default connect(mapStateToProps, mapDispatchToProps)(DataList)
diff --git a/examples/with-redux-persist/lib/with-redux-store.js b/examples/with-redux-persist/lib/with-redux-store.js
index 9b6ce3265e..ed3a15492b 100644
--- a/examples/with-redux-persist/lib/with-redux-store.js
+++ b/examples/with-redux-persist/lib/with-redux-store.js
@@ -17,7 +17,7 @@ function getOrCreateStore(initialState) {
   return window[__NEXT_REDUX_STORE__]
 }
 
-export default App => {
+export default (App) => {
   return class AppWithRedux extends Component {
     static async getInitialProps(appContext) {
       // Get or Create the store with `undefined` as initialState
diff --git a/examples/with-redux-persist/store.js b/examples/with-redux-persist/store.js
index f89553dd90..1bcce762ae 100644
--- a/examples/with-redux-persist/store.js
+++ b/examples/with-redux-persist/store.js
@@ -73,7 +73,7 @@ export const resetCount = () => {
   return { type: actionTypes.RESET }
 }
 
-export const loadExampleData = data => {
+export const loadExampleData = (data) => {
   return { type: actionTypes.LOAD_EXAMPLE_DATA, data }
 }
 
diff --git a/examples/with-redux-saga/README.md b/examples/with-redux-saga/README.md
index b3f4e0ed4c..373d220f9a 100644
--- a/examples/with-redux-saga/README.md
+++ b/examples/with-redux-saga/README.md
@@ -97,7 +97,7 @@ import nextReduxSaga from 'next-redux-saga'
 import configureStore from './store'
 
 export function withReduxSaga(...connectArgs) {
-  return BaseComponent =>
+  return (BaseComponent) =>
     withRedux(configureStore, ...connectArgs)(nextReduxSaga(BaseComponent))
 }
 
diff --git a/examples/with-redux-saga/components/clock.js b/examples/with-redux-saga/components/clock.js
index 3170784cf7..402e83c4f9 100644
--- a/examples/with-redux-saga/components/clock.js
+++ b/examples/with-redux-saga/components/clock.js
@@ -1,6 +1,6 @@
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
 
-const format = t => {
+const format = (t) => {
   const hours = t.getUTCHours()
   const minutes = t.getUTCMinutes()
   const seconds = t.getUTCSeconds()
diff --git a/examples/with-redux-saga/components/page.js b/examples/with-redux-saga/components/page.js
index 59eae329e6..bcc5f3bb6b 100644
--- a/examples/with-redux-saga/components/page.js
+++ b/examples/with-redux-saga/components/page.js
@@ -33,4 +33,4 @@ function Page({
   )
 }
 
-export default connect(state => state)(Page)
+export default connect((state) => state)(Page)
diff --git a/examples/with-redux-saga/store.js b/examples/with-redux-saga/store.js
index 1588d85ce1..4ac635321a 100644
--- a/examples/with-redux-saga/store.js
+++ b/examples/with-redux-saga/store.js
@@ -4,7 +4,7 @@ import createSagaMiddleware from 'redux-saga'
 import rootReducer, { exampleInitialState } from './reducer'
 import rootSaga from './saga'
 
-const bindMiddleware = middleware => {
+const bindMiddleware = (middleware) => {
   if (process.env.NODE_ENV !== 'production') {
     const { composeWithDevTools } = require('redux-devtools-extension')
     return composeWithDevTools(applyMiddleware(...middleware))
diff --git a/examples/with-redux-thunk/actions.js b/examples/with-redux-thunk/actions.js
index a0ab26810c..081ec97e1e 100644
--- a/examples/with-redux-thunk/actions.js
+++ b/examples/with-redux-thunk/actions.js
@@ -1,14 +1,14 @@
 import * as types from './types'
 
 // INITIALIZES CLOCK ON SERVER
-export const serverRenderClock = isServer => dispatch =>
+export const serverRenderClock = (isServer) => (dispatch) =>
   dispatch({
     type: types.TICK,
     payload: { light: !isServer, ts: Date.now() },
   })
 
 // INITIALIZES CLOCK ON CLIENT
-export const startClock = () => dispatch =>
+export const startClock = () => (dispatch) =>
   setInterval(() => {
     dispatch({ type: types.TICK, payload: { light: true, ts: Date.now() } })
   }, 1000)
diff --git a/examples/with-redux-thunk/components/clock.js b/examples/with-redux-thunk/components/clock.js
index 50a49693f6..b853d61fc4 100644
--- a/examples/with-redux-thunk/components/clock.js
+++ b/examples/with-redux-thunk/components/clock.js
@@ -1,6 +1,6 @@
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
 const Clock = ({ lastUpdate, light }) => (
diff --git a/examples/with-redux-thunk/components/counter.js b/examples/with-redux-thunk/components/counter.js
index c2ae95f8e8..0efda518ba 100644
--- a/examples/with-redux-thunk/components/counter.js
+++ b/examples/with-redux-thunk/components/counter.js
@@ -2,7 +2,7 @@ import { useSelector, useDispatch } from 'react-redux'
 import { incrementCount, decrementCount, resetCount } from '../actions'
 
 const Counter = () => {
-  const count = useSelector(state => state.counter)
+  const count = useSelector((state) => state.counter)
   const dispatch = useDispatch()
 
   return (
diff --git a/examples/with-redux-thunk/components/examples.js b/examples/with-redux-thunk/components/examples.js
index 59d0084a95..0a0e962aa9 100644
--- a/examples/with-redux-thunk/components/examples.js
+++ b/examples/with-redux-thunk/components/examples.js
@@ -3,8 +3,8 @@ import Clock from './clock'
 import Counter from './counter'
 
 const Examples = () => {
-  const lastUpdate = useSelector(state => state.timer.lastUpdate)
-  const light = useSelector(state => state.timer.light)
+  const lastUpdate = useSelector((state) => state.timer.lastUpdate)
+  const light = useSelector((state) => state.timer.light)
 
   return (
     <div style={{ marginBottom: 10 }}>
diff --git a/examples/with-redux-thunk/lib/with-redux-store.js b/examples/with-redux-thunk/lib/with-redux-store.js
index 708c675dc2..ebac5214a1 100644
--- a/examples/with-redux-thunk/lib/with-redux-store.js
+++ b/examples/with-redux-thunk/lib/with-redux-store.js
@@ -16,7 +16,7 @@ function getOrCreateStore(initialState) {
   return window[__NEXT_REDUX_STORE__]
 }
 
-export default App => {
+export default (App) => {
   return class AppWithRedux extends Component {
     static async getInitialProps(appContext) {
       // Get or Create the store with `undefined` as initialState
diff --git a/examples/with-redux-thunk/pages/show-redux-state.js b/examples/with-redux-thunk/pages/show-redux-state.js
index a23c374b7e..684288c3b4 100644
--- a/examples/with-redux-thunk/pages/show-redux-state.js
+++ b/examples/with-redux-thunk/pages/show-redux-state.js
@@ -9,7 +9,7 @@ const codeStyle = {
   marginBottom: 10,
 }
 
-const ShowReduxState = state => (
+const ShowReduxState = (state) => (
   <>
     <pre style={codeStyle}>
       <code>{JSON.stringify(state, null, 4)}</code>
@@ -20,6 +20,6 @@ const ShowReduxState = state => (
   </>
 )
 
-const mapDispatchToProps = state => state
+const mapDispatchToProps = (state) => state
 
 export default connect(mapDispatchToProps)(ShowReduxState)
diff --git a/examples/with-redux-thunk/store.js b/examples/with-redux-thunk/store.js
index 082638e2c0..93f19957be 100644
--- a/examples/with-redux-thunk/store.js
+++ b/examples/with-redux-thunk/store.js
@@ -4,7 +4,7 @@ import thunkMiddleware from 'redux-thunk'
 import reducers from './reducers'
 
 // CREATING INITIAL STORE
-export default initialState => {
+export default (initialState) => {
   const store = createStore(
     reducers,
     initialState,
diff --git a/examples/with-redux-toolkit/components/clock.js b/examples/with-redux-toolkit/components/clock.js
index 0b81f9d6bc..87e7b80c35 100644
--- a/examples/with-redux-toolkit/components/clock.js
+++ b/examples/with-redux-toolkit/components/clock.js
@@ -1,7 +1,7 @@
 import { useSelector, shallowEqual } from 'react-redux'
 
 const useClock = () => {
-  return useSelector(state => {
+  return useSelector((state) => {
     return {
       lastUpdate: state.lastUpdate,
       light: state.light,
@@ -9,7 +9,7 @@ const useClock = () => {
   }, shallowEqual)
 }
 
-const formatTime = time => {
+const formatTime = (time) => {
   // cut off except hh:mm:ss
   return new Date(time).toJSON().slice(11, 19)
 }
diff --git a/examples/with-redux-toolkit/components/counter.js b/examples/with-redux-toolkit/components/counter.js
index 98661a8336..c78f02e905 100644
--- a/examples/with-redux-toolkit/components/counter.js
+++ b/examples/with-redux-toolkit/components/counter.js
@@ -2,7 +2,7 @@ import { createAction } from '@reduxjs/toolkit'
 import { useSelector, useDispatch } from 'react-redux'
 
 const useCounter = () => {
-  const count = useSelector(state => state.count)
+  const count = useSelector((state) => state.count)
   const dispatch = useDispatch()
   const increment = () => dispatch(createAction('INCREMENT')())
   const decrement = () => dispatch(createAction('DECREMENT')())
diff --git a/examples/with-redux-toolkit/pages/index.js b/examples/with-redux-toolkit/pages/index.js
index f365719ac6..c6aa5c2f24 100644
--- a/examples/with-redux-toolkit/pages/index.js
+++ b/examples/with-redux-toolkit/pages/index.js
@@ -4,7 +4,7 @@ import useInterval from '../lib/useInterval'
 import Clock from '../components/clock'
 import Counter from '../components/counter'
 
-const tick = createAction('TICK', light => {
+const tick = createAction('TICK', (light) => {
   return {
     payload: {
       light: light,
@@ -28,4 +28,4 @@ const IndexPage = ({ dispatch }) => {
   )
 }
 
-export default connect(state => state)(IndexPage)
+export default connect((state) => state)(IndexPage)
diff --git a/examples/with-redux-wrapper/components/AddCount.js b/examples/with-redux-wrapper/components/AddCount.js
index f3b49de241..5f8361552c 100644
--- a/examples/with-redux-wrapper/components/AddCount.js
+++ b/examples/with-redux-wrapper/components/AddCount.js
@@ -19,11 +19,11 @@ const AddCount = ({ count, addCount }) => {
   )
 }
 
-const mapStateToProps = state => ({
+const mapStateToProps = (state) => ({
   count: state.count.count,
 })
 
-const mapDispatchToProps = dispatch => {
+const mapDispatchToProps = (dispatch) => {
   return {
     addCount: bindActionCreators(addCount, dispatch),
   }
diff --git a/examples/with-redux-wrapper/components/Clock.js b/examples/with-redux-wrapper/components/Clock.js
index 9fb286e174..3b3169ff64 100644
--- a/examples/with-redux-wrapper/components/Clock.js
+++ b/examples/with-redux-wrapper/components/Clock.js
@@ -19,7 +19,7 @@ export default ({ lastUpdate, light }) => {
   )
 }
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
diff --git a/examples/with-redux-wrapper/components/Page.js b/examples/with-redux-wrapper/components/Page.js
index 9c29785bd8..8cd83aa81b 100644
--- a/examples/with-redux-wrapper/components/Page.js
+++ b/examples/with-redux-wrapper/components/Page.js
@@ -16,4 +16,4 @@ const Page = ({ title, linkTo, tick }) => (
   </div>
 )
 
-export default connect(state => state)(Page)
+export default connect((state) => state)(Page)
diff --git a/examples/with-redux-wrapper/pages/_app.js b/examples/with-redux-wrapper/pages/_app.js
index 364eced858..c53551389f 100644
--- a/examples/with-redux-wrapper/pages/_app.js
+++ b/examples/with-redux-wrapper/pages/_app.js
@@ -3,7 +3,7 @@ import { Provider } from 'react-redux'
 import withRedux from 'next-redux-wrapper'
 import { initStore } from '../store/store'
 
-const MyApp = props => {
+const MyApp = (props) => {
   const { Component, pageProps, store } = props
   return (
     <Provider store={store}>
diff --git a/examples/with-redux-wrapper/pages/index.js b/examples/with-redux-wrapper/pages/index.js
index 2345548275..72ae45fc42 100644
--- a/examples/with-redux-wrapper/pages/index.js
+++ b/examples/with-redux-wrapper/pages/index.js
@@ -5,7 +5,7 @@ import { startClock, serverRenderClock } from '../store/tick/action'
 import { connect } from 'react-redux'
 import Page from '../components/Page'
 
-const Counter = props => {
+const Counter = (props) => {
   useEffect(() => {
     const timer = props.startClock()
 
@@ -23,7 +23,7 @@ Counter.getInitialProps = async ({ store, isServer }) => {
   return { isServer }
 }
 
-const mapDispatchToProps = dispatch => {
+const mapDispatchToProps = (dispatch) => {
   return {
     addCount: bindActionCreators(addCount, dispatch),
     startClock: bindActionCreators(startClock, dispatch),
diff --git a/examples/with-redux-wrapper/pages/other.js b/examples/with-redux-wrapper/pages/other.js
index 3d0c06b4a0..90560b000f 100644
--- a/examples/with-redux-wrapper/pages/other.js
+++ b/examples/with-redux-wrapper/pages/other.js
@@ -5,7 +5,7 @@ import { startClock, serverRenderClock } from '../store/tick/action'
 import { connect } from 'react-redux'
 import Page from '../components/Page'
 
-const Counter = props => {
+const Counter = (props) => {
   useEffect(() => {
     const timer = props.startClock()
 
@@ -23,7 +23,7 @@ Counter.getInitialProps = async ({ store, isServer }) => {
   return { isServer }
 }
 
-const mapDispatchToProps = dispatch => {
+const mapDispatchToProps = (dispatch) => {
   return {
     addCount: bindActionCreators(addCount, dispatch),
     startClock: bindActionCreators(startClock, dispatch),
diff --git a/examples/with-redux-wrapper/store/count/action.js b/examples/with-redux-wrapper/store/count/action.js
index 65e1b0f324..ec76af0b37 100644
--- a/examples/with-redux-wrapper/store/count/action.js
+++ b/examples/with-redux-wrapper/store/count/action.js
@@ -2,6 +2,6 @@ export const countActionTypes = {
   ADD: 'ADD',
 }
 
-export const addCount = () => dispatch => {
+export const addCount = () => (dispatch) => {
   return dispatch({ type: countActionTypes.ADD })
 }
diff --git a/examples/with-redux-wrapper/store/store.js b/examples/with-redux-wrapper/store/store.js
index f3a404b29f..ab2312e7b7 100644
--- a/examples/with-redux-wrapper/store/store.js
+++ b/examples/with-redux-wrapper/store/store.js
@@ -3,7 +3,7 @@ import thunkMiddleware from 'redux-thunk'
 import count from './count/reducer'
 import tick from './tick/reducer'
 
-const bindMiddleware = middleware => {
+const bindMiddleware = (middleware) => {
   if (process.env.NODE_ENV !== 'production') {
     const { composeWithDevTools } = require('redux-devtools-extension')
     return composeWithDevTools(applyMiddleware(...middleware))
diff --git a/examples/with-redux-wrapper/store/tick/action.js b/examples/with-redux-wrapper/store/tick/action.js
index a3f4470b66..ba4ace2f6b 100644
--- a/examples/with-redux-wrapper/store/tick/action.js
+++ b/examples/with-redux-wrapper/store/tick/action.js
@@ -2,7 +2,7 @@ export const tickActionTypes = {
   TICK: 'TICK',
 }
 
-export const serverRenderClock = isServer => dispatch => {
+export const serverRenderClock = (isServer) => (dispatch) => {
   return dispatch({
     type: tickActionTypes.TICK,
     light: !isServer,
@@ -10,7 +10,7 @@ export const serverRenderClock = isServer => dispatch => {
   })
 }
 
-export const startClock = () => dispatch => {
+export const startClock = () => (dispatch) => {
   return setInterval(
     () => dispatch({ type: tickActionTypes.TICK, light: true, ts: Date.now() }),
     1000
diff --git a/examples/with-redux/components/clock.js b/examples/with-redux/components/clock.js
index e23d3e70f9..8c8709553a 100644
--- a/examples/with-redux/components/clock.js
+++ b/examples/with-redux/components/clock.js
@@ -3,7 +3,7 @@ import { useSelector, shallowEqual } from 'react-redux'
 
 const useClock = () => {
   return useSelector(
-    state => ({
+    (state) => ({
       lastUpdate: state.lastUpdate,
       light: state.light,
     }),
@@ -11,7 +11,7 @@ const useClock = () => {
   )
 }
 
-const formatTime = time => {
+const formatTime = (time) => {
   // cut off except hh:mm:ss
   return new Date(time).toJSON().slice(11, 19)
 }
diff --git a/examples/with-redux/components/counter.js b/examples/with-redux/components/counter.js
index a161c6802c..3edd66d98f 100644
--- a/examples/with-redux/components/counter.js
+++ b/examples/with-redux/components/counter.js
@@ -2,7 +2,7 @@ import React from 'react'
 import { useSelector, useDispatch } from 'react-redux'
 
 const useCounter = () => {
-  const count = useSelector(state => state.count)
+  const count = useSelector((state) => state.count)
   const dispatch = useDispatch()
   const increment = () =>
     dispatch({
diff --git a/examples/with-redux/lib/redux.js b/examples/with-redux/lib/redux.js
index 90c94279bd..535bbdac7c 100644
--- a/examples/with-redux/lib/redux.js
+++ b/examples/with-redux/lib/redux.js
@@ -31,7 +31,7 @@ export const withRedux = (PageComponent, { ssr = true } = {}) => {
   }
 
   if (ssr || PageComponent.getInitialProps) {
-    WithRedux.getInitialProps = async context => {
+    WithRedux.getInitialProps = async (context) => {
       // Get or Create the store with `undefined` as initialState
       // This allows you to set a custom default initialState
       const reduxStore = getOrInitializeStore()
@@ -57,7 +57,7 @@ export const withRedux = (PageComponent, { ssr = true } = {}) => {
 }
 
 let reduxStore
-const getOrInitializeStore = initialState => {
+const getOrInitializeStore = (initialState) => {
   // Always make a new store if server, otherwise state is shared between requests
   if (typeof window === 'undefined') {
     return initializeStore(initialState)
diff --git a/examples/with-relay-modern/lib/createRelayEnvironment.js b/examples/with-relay-modern/lib/createRelayEnvironment.js
index 41c9a723e1..d152c0d44e 100644
--- a/examples/with-relay-modern/lib/createRelayEnvironment.js
+++ b/examples/with-relay-modern/lib/createRelayEnvironment.js
@@ -15,7 +15,7 @@ function fetchQuery(operation, variables, cacheConfig, uploadables) {
       query: operation.text, // GraphQL text from input
       variables,
     }),
-  }).then(response => response.json())
+  }).then((response) => response.json())
 }
 
 export default function initEnvironment({ records = {} } = {}) {
diff --git a/examples/with-relay-modern/lib/withData.js b/examples/with-relay-modern/lib/withData.js
index 46ba757db9..645b0b0e55 100644
--- a/examples/with-relay-modern/lib/withData.js
+++ b/examples/with-relay-modern/lib/withData.js
@@ -24,10 +24,7 @@ export default (ComposedComponent, options = {}) => {
         // TODO: Consider RelayQueryResponseCache
         // https://github.com/facebook/relay/issues/1687#issuecomment-302931855
         queryProps = await fetchQuery(environment, options.query, variables)
-        queryRecords = environment
-          .getStore()
-          .getSource()
-          .toJSON()
+        queryRecords = environment.getStore().getSource().toJSON()
       }
 
       return {
diff --git a/examples/with-relay-modern/next.config.js b/examples/with-relay-modern/next.config.js
index 6719eff113..12aabac545 100644
--- a/examples/with-relay-modern/next.config.js
+++ b/examples/with-relay-modern/next.config.js
@@ -4,7 +4,7 @@ const path = require('path')
 const Dotenv = require('dotenv-webpack')
 
 module.exports = {
-  webpack: config => {
+  webpack: (config) => {
     config.plugins = config.plugins || []
 
     config.plugins = [
diff --git a/examples/with-relay-modern/schema/init-schema.graphql b/examples/with-relay-modern/schema/init-schema.graphql
index c7c5711d28..aafc0574a9 100644
--- a/examples/with-relay-modern/schema/init-schema.graphql
+++ b/examples/with-relay-modern/schema/init-schema.graphql
@@ -4,4 +4,4 @@ type BlogPost implements Node {
   id: ID! @isUnique
   title: String!
   updatedAt: DateTime!
-}
\ No newline at end of file
+}
diff --git a/examples/with-rematch/pages/github-users.js b/examples/with-rematch/pages/github-users.js
index 32e224d362..5a40f6495f 100644
--- a/examples/with-rematch/pages/github-users.js
+++ b/examples/with-rematch/pages/github-users.js
@@ -32,7 +32,7 @@ class Github extends Component {
         <p>
           <button onClick={fetchUsers}>Get users</button>
         </p>
-        {userList.map(user => (
+        {userList.map((user) => (
           <div key={user.login}>
             <Link href={user.html_url} passHref>
               <a>
@@ -51,7 +51,7 @@ class Github extends Component {
   }
 }
 
-const mapState = state => ({
+const mapState = (state) => ({
   userList: state.github.users,
   isLoading: state.github.isLoading,
 })
diff --git a/examples/with-rematch/pages/index.js b/examples/with-rematch/pages/index.js
index e1f98c65bf..3bbfd37649 100644
--- a/examples/with-rematch/pages/index.js
+++ b/examples/with-rematch/pages/index.js
@@ -26,13 +26,13 @@ class Home extends Component {
   }
 }
 
-const mapState = state => ({
+const mapState = (state) => ({
   counter: state.counter,
 })
 
 const mapDispatch = ({ counter: { increment, incrementAsync } }) => ({
   increment: () => increment(1),
-  incrementBy: amount => () => increment(amount),
+  incrementBy: (amount) => () => increment(amount),
   incrementAsync: () => incrementAsync(1),
 })
 
diff --git a/examples/with-rematch/shared/components/counter-display.js b/examples/with-rematch/shared/components/counter-display.js
index dfb307f449..140f1eb7bb 100644
--- a/examples/with-rematch/shared/components/counter-display.js
+++ b/examples/with-rematch/shared/components/counter-display.js
@@ -22,7 +22,7 @@ class CounterDisplay extends Component {
   }
 }
 
-const mapState = state => ({
+const mapState = (state) => ({
   counter: state.counter,
 })
 
diff --git a/examples/with-rematch/shared/models/counter.js b/examples/with-rematch/shared/models/counter.js
index 1e5f5188c0..38e53a1ece 100644
--- a/examples/with-rematch/shared/models/counter.js
+++ b/examples/with-rematch/shared/models/counter.js
@@ -10,7 +10,7 @@ const counter = {
     // handle state changes with impure functions.
     // use async/await for async actions
     async incrementAsync(payload, rootState) {
-      await new Promise(resolve => setTimeout(resolve, 1000))
+      await new Promise((resolve) => setTimeout(resolve, 1000))
       this.increment(payload)
     },
   },
diff --git a/examples/with-rematch/shared/withRematch.js b/examples/with-rematch/shared/withRematch.js
index acac06ee39..06d6de5c0b 100644
--- a/examples/with-rematch/shared/withRematch.js
+++ b/examples/with-rematch/shared/withRematch.js
@@ -18,7 +18,7 @@ function getOrCreateStore(initialState) {
   return window[__NEXT_REDUX_STORE__]
 }
 
-export default App => {
+export default (App) => {
   return class AppWithRematch extends React.Component {
     static async getInitialProps(appContext) {
       // Get or Create the store with `undefined` as initialState
diff --git a/examples/with-segment-analytics/components/Page.js b/examples/with-segment-analytics/components/Page.js
index 571ade30aa..c5d50c3e14 100644
--- a/examples/with-segment-analytics/components/Page.js
+++ b/examples/with-segment-analytics/components/Page.js
@@ -3,7 +3,7 @@ import Router from 'next/router'
 import Header from './Header'
 
 // Track client-side page views with Segment
-Router.events.on('routeChangeComplete', url => {
+Router.events.on('routeChangeComplete', (url) => {
   window.analytics.page(url)
 })
 
diff --git a/examples/with-segment-analytics/pages/contact.js b/examples/with-segment-analytics/pages/contact.js
index cd08ff1a2b..f1ec6d4dfe 100644
--- a/examples/with-segment-analytics/pages/contact.js
+++ b/examples/with-segment-analytics/pages/contact.js
@@ -35,11 +35,11 @@ export default class extends Component {
     )
   }
 
-  handleInput = e => {
+  handleInput = (e) => {
     this.setState({ message: e.target.value })
   }
 
-  handleSubmit = e => {
+  handleSubmit = (e) => {
     e.preventDefault()
     global.analytics.track('Form Submitted', {
       message: this.state.message,
diff --git a/examples/with-sentry-simple/pages/client/test7.js b/examples/with-sentry-simple/pages/client/test7.js
index 9d9acbeb1d..7267de64cf 100644
--- a/examples/with-sentry-simple/pages/client/test7.js
+++ b/examples/with-sentry-simple/pages/client/test7.js
@@ -1,7 +1,7 @@
 import React from 'react'
 
 const Test7 = () => {
-  React.useEffect(function() {
+  React.useEffect(function () {
     async function doTest() {
       const doAsyncWork = () => Promise.reject(new Error('Client Test 7'))
       const result = await doAsyncWork()
diff --git a/examples/with-sentry/server.js b/examples/with-sentry/server.js
index 75dcf81850..a4911ca3f6 100644
--- a/examples/with-sentry/server.js
+++ b/examples/with-sentry/server.js
@@ -26,7 +26,7 @@ function sessionCookie(req, res, next) {
   next()
 }
 
-const sourcemapsForSentryOnly = token => (req, res, next) => {
+const sourcemapsForSentryOnly = (token) => (req, res, next) => {
   // In production we only want to serve source maps for Sentry
   if (!dev && !!token && req.headers['x-sentry-token'] !== token) {
     res
@@ -51,7 +51,7 @@ app.prepare().then(() => {
     .use(handler)
     // This handles errors if they are thrown before reaching the app
     .use(Sentry.Handlers.errorHandler())
-    .listen(port, err => {
+    .listen(port, (err) => {
       if (err) {
         throw err
       }
diff --git a/examples/with-sentry/utils/sentry.js b/examples/with-sentry/utils/sentry.js
index 6970f9dfcd..345311fd03 100644
--- a/examples/with-sentry/utils/sentry.js
+++ b/examples/with-sentry/utils/sentry.js
@@ -31,7 +31,7 @@ module.exports = (release = process.env.SENTRY_RELEASE) => {
   return {
     Sentry,
     captureException: (err, ctx) => {
-      Sentry.configureScope(scope => {
+      Sentry.configureScope((scope) => {
         if (err.message) {
           // De-duplication currently doesn't work correctly for SSR / browser errors
           // so we force deduplication by error message if it is present
@@ -74,7 +74,7 @@ module.exports = (release = process.env.SENTRY_RELEASE) => {
           }
 
           if (errorInfo) {
-            Object.keys(errorInfo).forEach(key =>
+            Object.keys(errorInfo).forEach((key) =>
               scope.setExtra(key, errorInfo[key])
             )
           }
diff --git a/examples/with-slate/lib/useCustomKeygen.js b/examples/with-slate/lib/useCustomKeygen.js
index f368cc71ab..e706ddbc01 100644
--- a/examples/with-slate/lib/useCustomKeygen.js
+++ b/examples/with-slate/lib/useCustomKeygen.js
@@ -1,7 +1,7 @@
 import { useRef } from 'react'
 import { KeyUtils } from 'slate'
 
-const useCustomKeygen = uniqueKey => {
+const useCustomKeygen = (uniqueKey) => {
   const ref = useRef(null)
   if (!ref.current || ref.current !== uniqueKey) {
     let n = 0
diff --git a/examples/with-slate/pages/index.js b/examples/with-slate/pages/index.js
index 78ccb28025..a98bff5c3a 100644
--- a/examples/with-slate/pages/index.js
+++ b/examples/with-slate/pages/index.js
@@ -2,7 +2,7 @@ import React from 'react'
 import Link from 'next/link'
 import NextEditor from '../components/NextEditor'
 
-const IndexPage = props => {
+const IndexPage = (props) => {
   return (
     <React.Fragment>
       <Link href="/multiple">
diff --git a/examples/with-static-export/pages/index.js b/examples/with-static-export/pages/index.js
index af2c81ce98..535bf7f526 100644
--- a/examples/with-static-export/pages/index.js
+++ b/examples/with-static-export/pages/index.js
@@ -25,7 +25,7 @@ export default function IndexPage({ postList }) {
       <h1>List of posts</h1>
 
       <section>
-        {postList.map(post => (
+        {postList.map((post) => (
           <Post {...post} key={post.id} />
         ))}
       </section>
diff --git a/examples/with-static-export/pages/post/[id].js b/examples/with-static-export/pages/post/[id].js
index 2aa8d43271..23811bca5d 100644
--- a/examples/with-static-export/pages/post/[id].js
+++ b/examples/with-static-export/pages/post/[id].js
@@ -8,7 +8,7 @@ export async function getStaticPaths() {
   )
   const postList = await response.json()
   return {
-    paths: postList.map(post => {
+    paths: postList.map((post) => {
       return {
         params: {
           id: `${post.id}`,
diff --git a/examples/with-stitches/pages/_document.js b/examples/with-stitches/pages/_document.js
index abccfd71b6..4af32d75cb 100644
--- a/examples/with-stitches/pages/_document.js
+++ b/examples/with-stitches/pages/_document.js
@@ -11,7 +11,7 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => <App {...props} serverCss={css} />,
+          enhanceApp: (App) => (props) => <App {...props} serverCss={css} />,
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-stitches/pages/index.js b/examples/with-stitches/pages/index.js
index 2f29d6c20b..dfe78a0b8a 100644
--- a/examples/with-stitches/pages/index.js
+++ b/examples/with-stitches/pages/index.js
@@ -1,6 +1,6 @@
 import { styled } from './css'
 
-const Header = styled.h1(css => css.color('RED'))
+const Header = styled.h1((css) => css.color('RED'))
 
 export default function Home() {
   return <Header>Hello world</Header>
diff --git a/examples/with-stomp/useStomp.js b/examples/with-stomp/useStomp.js
index 76d8cfc4b0..3ed05d3584 100644
--- a/examples/with-stomp/useStomp.js
+++ b/examples/with-stomp/useStomp.js
@@ -1,13 +1,13 @@
 import { useState, useEffect, useCallback } from 'react'
 import useClient from './useClient'
 
-const useStomp = topic => {
+const useStomp = (topic) => {
   const [message, setMessage] = useState({})
   const client = useClient()
 
   // subscribe to a channel, then listen to the messages.
   const subscribe = useCallback(() => {
-    client.subscribe(topic, msg => {
+    client.subscribe(topic, (msg) => {
       const change = JSON.parse(msg.body)
       setMessage(change)
     })
diff --git a/examples/with-strict-csp-hash/pages/_document.js b/examples/with-strict-csp-hash/pages/_document.js
index 919fdf8148..01a7241df3 100644
--- a/examples/with-strict-csp-hash/pages/_document.js
+++ b/examples/with-strict-csp-hash/pages/_document.js
@@ -1,7 +1,7 @@
 import crypto from 'crypto'
 import Document, { Head, Main, NextScript } from 'next/document'
 
-const cspHashOf = text => {
+const cspHashOf = (text) => {
   const hash = crypto.createHash('sha256')
   hash.update(text)
   return `'sha256-${hash.digest('base64')}'`
diff --git a/examples/with-strict-csp/server.js b/examples/with-strict-csp/server.js
index 81c99f4c14..581f03144a 100644
--- a/examples/with-strict-csp/server.js
+++ b/examples/with-strict-csp/server.js
@@ -14,7 +14,7 @@ app.prepare().then(() => {
 
   server.use(handle)
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) throw err
     console.log(`> Ready on http://localhost:${port}`)
   })
diff --git a/examples/with-stripe-typescript/components/CheckoutForm.tsx b/examples/with-stripe-typescript/components/CheckoutForm.tsx
index 3844523570..d092cfb27b 100644
--- a/examples/with-stripe-typescript/components/CheckoutForm.tsx
+++ b/examples/with-stripe-typescript/components/CheckoutForm.tsx
@@ -14,13 +14,13 @@ const CheckoutForm: React.FunctionComponent = () => {
   })
   const stripe = useStripe()
 
-  const handleInputChange: React.ChangeEventHandler<HTMLInputElement> = e =>
+  const handleInputChange: React.ChangeEventHandler<HTMLInputElement> = (e) =>
     setInput({
       ...input,
       [e.currentTarget.name]: e.currentTarget.value,
     })
 
-  const handleSubmit: React.FormEventHandler<HTMLFormElement> = async e => {
+  const handleSubmit: React.FormEventHandler<HTMLFormElement> = async (e) => {
     e.preventDefault()
     // Create a Checkout Session.
     const response = await fetchPostJSON('/api/checkout_sessions', {
diff --git a/examples/with-stripe-typescript/components/ElementsForm.tsx b/examples/with-stripe-typescript/components/ElementsForm.tsx
index 0b02f10ec1..b76bb577df 100644
--- a/examples/with-stripe-typescript/components/ElementsForm.tsx
+++ b/examples/with-stripe-typescript/components/ElementsForm.tsx
@@ -69,13 +69,13 @@ const ElementsForm: React.FunctionComponent = () => {
     }
   }
 
-  const handleInputChange: React.ChangeEventHandler<HTMLInputElement> = e =>
+  const handleInputChange: React.ChangeEventHandler<HTMLInputElement> = (e) =>
     setInput({
       ...input,
       [e.currentTarget.name]: e.currentTarget.value,
     })
 
-  const handleSubmit: React.FormEventHandler<HTMLFormElement> = async e => {
+  const handleSubmit: React.FormEventHandler<HTMLFormElement> = async (e) => {
     e.preventDefault()
     // Abort if form isn't valid
     if (!e.currentTarget.reportValidity()) return
@@ -143,7 +143,7 @@ const ElementsForm: React.FunctionComponent = () => {
           <div className="FormRow elements-style">
             <CardElement
               options={CARD_OPTIONS}
-              onChange={e => {
+              onChange={(e) => {
                 if (e.error) {
                   setPayment({ status: 'error' })
                   setErrorMessage(e.error.message ?? 'An unknown error occured')
diff --git a/examples/with-stripe-typescript/utils/api-helpers.ts b/examples/with-stripe-typescript/utils/api-helpers.ts
index 13d8772ec8..6d6f16780b 100644
--- a/examples/with-stripe-typescript/utils/api-helpers.ts
+++ b/examples/with-stripe-typescript/utils/api-helpers.ts
@@ -1,6 +1,6 @@
 export async function fetchGetJSON(url: string) {
   try {
-    const data = await fetch(url).then(res => res.json())
+    const data = await fetch(url).then((res) => res.json())
     return data
   } catch (err) {
     throw new Error(err.message)
diff --git a/examples/with-styled-components-rtl/pages/_document.js b/examples/with-styled-components-rtl/pages/_document.js
index 4aae44fc0e..18640931a9 100644
--- a/examples/with-styled-components-rtl/pages/_document.js
+++ b/examples/with-styled-components-rtl/pages/_document.js
@@ -7,7 +7,7 @@ export default class MyDocument extends Document {
   static getInitialProps({ renderPage }) {
     const sheet = new ServerStyleSheet()
 
-    const page = renderPage(App => props =>
+    const page = renderPage((App) => (props) =>
       sheet.collectStyles(
         <StyleSheetManager stylisPlugins={[stylisRTLPlugin]}>
           <App {...props} />
diff --git a/examples/with-styled-components/pages/_document.js b/examples/with-styled-components/pages/_document.js
index d43c7f5095..2a59afeb93 100644
--- a/examples/with-styled-components/pages/_document.js
+++ b/examples/with-styled-components/pages/_document.js
@@ -9,7 +9,8 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+          enhanceApp: (App) => (props) =>
+            sheet.collectStyles(<App {...props} />),
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-styletron/next.config.js b/examples/with-styletron/next.config.js
index 92319cafb4..9facbdfb49 100644
--- a/examples/with-styletron/next.config.js
+++ b/examples/with-styletron/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: function(config) {
+  webpack: function (config) {
     config.externals = config.externals || {}
     config.externals['styletron-server'] = 'styletron-server'
     return config
diff --git a/examples/with-styletron/pages/_document.js b/examples/with-styletron/pages/_document.js
index 49eaacbeaf..0eb00f9da7 100644
--- a/examples/with-styletron/pages/_document.js
+++ b/examples/with-styletron/pages/_document.js
@@ -4,7 +4,7 @@ import { styletron } from '../styletron'
 
 class MyDocument extends Document {
   static getInitialProps(props) {
-    const page = props.renderPage(App => props => (
+    const page = props.renderPage((App) => (props) => (
       <StyletronProvider value={styletron}>
         <App {...props} />
       </StyletronProvider>
diff --git a/examples/with-three-js/pages/birds.js b/examples/with-three-js/pages/birds.js
index f9b2d4a042..282f57d041 100644
--- a/examples/with-three-js/pages/birds.js
+++ b/examples/with-three-js/pages/birds.js
@@ -64,7 +64,7 @@ const Birds = () => {
   })
 }
 
-const BirdsPage = props => {
+const BirdsPage = (props) => {
   useEffect(() => {
     GLTFLoader = require('three/examples/jsm/loaders/GLTFLoader').GLTFLoader
   }, [])
diff --git a/examples/with-three-js/pages/boxes.js b/examples/with-three-js/pages/boxes.js
index 8fba862a74..3ecdb28e41 100644
--- a/examples/with-three-js/pages/boxes.js
+++ b/examples/with-three-js/pages/boxes.js
@@ -1,7 +1,7 @@
 import React, { useRef, useState, Suspense } from 'react'
 import { Canvas, useFrame } from 'react-three-fiber'
 
-const Box = props => {
+const Box = (props) => {
   const mesh = useRef()
 
   const [hovered, setHover] = useState(false)
@@ -14,9 +14,9 @@ const Box = props => {
       {...props}
       ref={mesh}
       scale={active ? [6, 6, 6] : [5, 5, 5]}
-      onClick={e => setActive(!active)}
-      onPointerOver={e => setHover(true)}
-      onPointerOut={e => setHover(false)}
+      onClick={(e) => setActive(!active)}
+      onPointerOver={(e) => setHover(true)}
+      onPointerOut={(e) => setHover(false)}
     >
       <boxBufferGeometry attach="geometry" args={[1, 1, 1]} />
       <meshStandardMaterial
diff --git a/examples/with-typescript-graphql/lib/type-defs.graphqls b/examples/with-typescript-graphql/lib/type-defs.graphqls
index f198c8c143..ad9c06bcca 100644
--- a/examples/with-typescript-graphql/lib/type-defs.graphqls
+++ b/examples/with-typescript-graphql/lib/type-defs.graphqls
@@ -1,9 +1,9 @@
 type User {
-    id: ID!
-    name: String!
-    status: String!
+  id: ID!
+  name: String!
+  status: String!
 }
 
 type Query {
-    viewer: User!
+  viewer: User!
 }
diff --git a/examples/with-typescript-graphql/lib/viewer.graphql b/examples/with-typescript-graphql/lib/viewer.graphql
index 7f2a5b4faa..e5dd6140a9 100644
--- a/examples/with-typescript-graphql/lib/viewer.graphql
+++ b/examples/with-typescript-graphql/lib/viewer.graphql
@@ -1,7 +1,7 @@
 query Viewer {
-    viewer {
-        id
-        name
-        status
-    }
+  viewer {
+    id
+    name
+    status
+  }
 }
diff --git a/examples/with-typescript-styled-components/pages/_document.tsx b/examples/with-typescript-styled-components/pages/_document.tsx
index 94a21c0618..eb67e4c6d7 100644
--- a/examples/with-typescript-styled-components/pages/_document.tsx
+++ b/examples/with-typescript-styled-components/pages/_document.tsx
@@ -9,7 +9,8 @@ export default class MyDocument extends Document {
     try {
       ctx.renderPage = () =>
         originalRenderPage({
-          enhanceApp: App => props => sheet.collectStyles(<App {...props} />),
+          enhanceApp: (App) => (props) =>
+            sheet.collectStyles(<App {...props} />),
         })
 
       const initialProps = await Document.getInitialProps(ctx)
diff --git a/examples/with-typescript/components/List.tsx b/examples/with-typescript/components/List.tsx
index 679951d1ac..83183e7ba0 100644
--- a/examples/with-typescript/components/List.tsx
+++ b/examples/with-typescript/components/List.tsx
@@ -8,7 +8,7 @@ type Props = {
 
 const List: React.FunctionComponent<Props> = ({ items }) => (
   <ul>
-    {items.map(item => (
+    {items.map((item) => (
       <li key={item.id}>
         <ListItem data={item} />
       </li>
diff --git a/examples/with-typescript/pages/users/[id].tsx b/examples/with-typescript/pages/users/[id].tsx
index b1ec3ad164..79d5071be4 100644
--- a/examples/with-typescript/pages/users/[id].tsx
+++ b/examples/with-typescript/pages/users/[id].tsx
@@ -40,7 +40,7 @@ export default StaticPropsDetail
 
 export const getStaticPaths: GetStaticPaths = async () => {
   // Get the paths we want to pre-render based on users
-  const paths = sampleUserData.map(user => ({
+  const paths = sampleUserData.map((user) => ({
     params: { id: user.id.toString() },
   }))
 
@@ -55,7 +55,7 @@ export const getStaticPaths: GetStaticPaths = async () => {
 export const getStaticProps: GetStaticProps = async ({ params }) => {
   try {
     const id = params?.id
-    const item = sampleUserData.find(data => data.id === Number(id))
+    const item = sampleUserData.find((data) => data.id === Number(id))
     // By returning { props: item }, the StaticPropsDetail component
     // will receive `item` as a prop at build time
     return { props: { item } }
diff --git a/examples/with-unstated/components/Clock.js b/examples/with-unstated/components/Clock.js
index 69ae16cbbd..e72faae06b 100644
--- a/examples/with-unstated/components/Clock.js
+++ b/examples/with-unstated/components/Clock.js
@@ -1,8 +1,8 @@
 import ClockContainer from '../containers/clock'
 
-const pad = n => (n < 10 ? `0${n}` : n)
+const pad = (n) => (n < 10 ? `0${n}` : n)
 
-const format = t =>
+const format = (t) =>
   `${pad(t.getUTCHours())}:${pad(t.getUTCMinutes())}:${pad(t.getUTCSeconds())}`
 
 export default function Clock() {
diff --git a/examples/with-userbase/components/modal/index.js b/examples/with-userbase/components/modal/index.js
index 2cf0018b33..2d752982ca 100644
--- a/examples/with-userbase/components/modal/index.js
+++ b/examples/with-userbase/components/modal/index.js
@@ -62,7 +62,7 @@ function LoginModal({ toggle, modalType, setUser }) {
           type="text"
           placeholder="Username"
           value={username}
-          onChange={e => setUsername(e.target.value)}
+          onChange={(e) => setUsername(e.target.value)}
         />
       </div>
       <div className="mb-4">
@@ -78,7 +78,7 @@ function LoginModal({ toggle, modalType, setUser }) {
           type="password"
           placeholder="*******"
           value={password}
-          onChange={e => setPassword(e.target.value)}
+          onChange={(e) => setPassword(e.target.value)}
         />
       </div>
       <div className="flex items-center justify-between">
diff --git a/examples/with-userbase/components/todo-form/index.js b/examples/with-userbase/components/todo-form/index.js
index 53f2614450..e97ef5d987 100644
--- a/examples/with-userbase/components/todo-form/index.js
+++ b/examples/with-userbase/components/todo-form/index.js
@@ -9,7 +9,7 @@ function Todo({ name, done, toggleComplete, deleteTodo }) {
         <button
           type="button"
           className="mx-4 p-1 rounded bg-purple-400 text-white font-bold"
-          onClick={e => {
+          onClick={(e) => {
             e.preventDefault()
             toggleComplete()
           }}
@@ -18,7 +18,7 @@ function Todo({ name, done, toggleComplete, deleteTodo }) {
         </button>
         <button
           type="button"
-          onClick={e => {
+          onClick={(e) => {
             e.preventDefault()
             deleteTodo()
           }}
@@ -42,7 +42,7 @@ function TodoForm() {
         console.log('opening db...')
         await userbase.openDatabase({
           databaseName: 'next-userbase-todos',
-          changeHandler: function(items) {
+          changeHandler: function (items) {
             setTodos(items)
           },
         })
@@ -104,7 +104,7 @@ function TodoForm() {
   return (
     <form className="bg-white shadow-md rounded p-8" onSubmit={addTodo}>
       <ul>
-        {todos.map(todo => (
+        {todos.map((todo) => (
           <Todo
             key={todo.itemId}
             name={todo.item.name}
diff --git a/examples/with-userbase/postcss.config.js b/examples/with-userbase/postcss.config.js
index 23ffee56ff..f9328b6f35 100644
--- a/examples/with-userbase/postcss.config.js
+++ b/examples/with-userbase/postcss.config.js
@@ -10,7 +10,7 @@ module.exports = {
                 './pages/**/*.{js,jsx,ts,tsx}',
                 './components/**/*.{js,jsx,ts,tsx}',
               ],
-              defaultExtractor: content =>
+              defaultExtractor: (content) =>
                 content.match(/[\w-/:]+(?<!:)/g) || [],
             },
           ],
diff --git a/examples/with-videojs/components/Player.js b/examples/with-videojs/components/Player.js
index ef614a83b7..707d8eb37c 100644
--- a/examples/with-videojs/components/Player.js
+++ b/examples/with-videojs/components/Player.js
@@ -24,7 +24,7 @@ class Player extends Component {
     return (
       <div>
         <div data-vjs-player>
-          <video ref={node => (this.videoNode = node)} className="video-js" />
+          <video ref={(node) => (this.videoNode = node)} className="video-js" />
         </div>
       </div>
     )
diff --git a/examples/with-webassembly/pages/index.js b/examples/with-webassembly/pages/index.js
index c74387667b..57bd0b52fe 100644
--- a/examples/with-webassembly/pages/index.js
+++ b/examples/with-webassembly/pages/index.js
@@ -7,7 +7,7 @@ const RustComponent = dynamic({
     // Import the wasm module
     const rustModule = await import('../add.wasm')
     // Return a React component that calls the add_one method on the wasm module
-    return props => <div>{rustModule.add_one(props.number)}</div>
+    return (props) => <div>{rustModule.add_one(props.number)}</div>
   },
 })
 
diff --git a/examples/with-webpack-bundle-size-analyzer/next.config.js b/examples/with-webpack-bundle-size-analyzer/next.config.js
index 9e0709d4b7..eb7b76c963 100644
--- a/examples/with-webpack-bundle-size-analyzer/next.config.js
+++ b/examples/with-webpack-bundle-size-analyzer/next.config.js
@@ -4,7 +4,7 @@ const {
 const { ANALYZE } = process.env
 
 module.exports = {
-  webpack: function(config) {
+  webpack: function (config) {
     if (ANALYZE) {
       config.plugins.push(new WebpackBundleSizeAnalyzerPlugin('stats.txt'))
     }
diff --git a/examples/with-xstate/machines/counterMachine.js b/examples/with-xstate/machines/counterMachine.js
index dac1901273..f28a232718 100644
--- a/examples/with-xstate/machines/counterMachine.js
+++ b/examples/with-xstate/machines/counterMachine.js
@@ -1,7 +1,7 @@
 import { Machine, assign } from 'xstate'
 
-const increment = context => context.count + 1
-const decrement = context => context.count - 1
+const increment = (context) => context.count + 1
+const decrement = (context) => context.count - 1
 
 export const counterMachine = Machine({
   initial: 'active',
diff --git a/examples/z-experimental-refresh/components/ClickCount.js b/examples/z-experimental-refresh/components/ClickCount.js
index 9b736bc3de..2832666121 100644
--- a/examples/z-experimental-refresh/components/ClickCount.js
+++ b/examples/z-experimental-refresh/components/ClickCount.js
@@ -4,7 +4,7 @@ import styles from './ClickCount.module.css'
 export default function ClickCount() {
   const [count, setCount] = useState(0)
   const increment = useCallback(() => {
-    setCount(v => v + 1)
+    setCount((v) => v + 1)
   }, [setCount])
 
   return (
diff --git a/examples/z-experimental-refresh/pages/index.js b/examples/z-experimental-refresh/pages/index.js
index d1fc45483c..6346c5e117 100644
--- a/examples/z-experimental-refresh/pages/index.js
+++ b/examples/z-experimental-refresh/pages/index.js
@@ -16,7 +16,7 @@ function foo() {
 function Home() {
   const [count, setCount] = useState(0)
   const increment = useCallback(() => {
-    setCount(v => v + 1)
+    setCount((v) => v + 1)
   }, [setCount])
 
   useEffect(() => {
@@ -45,7 +45,7 @@ function Home() {
         <button
           className={styles.btn}
           type="button"
-          onClick={e => {
+          onClick={(e) => {
             setTimeout(() => document.parentNode(), 0)
             foo()
           }}
diff --git a/lint-staged.config.js b/lint-staged.config.js
index 2fb42b7d8d..63a07a654f 100644
--- a/lint-staged.config.js
+++ b/lint-staged.config.js
@@ -2,20 +2,20 @@ const escape = require('shell-quote').quote
 const isWin = process.platform === 'win32'
 
 module.exports = {
-  '**/*.{js,jsx,ts,tsx}': filenames => {
+  '**/*.{js,jsx,ts,tsx}': (filenames) => {
     const escapedFileNames = filenames
-      .map(filename => `"${isWin ? filename : escape([filename])}"`)
+      .map((filename) => `"${isWin ? filename : escape([filename])}"`)
       .join(' ')
     return [
       `prettier --with-node-modules --ignore-path .prettierignore_staged --write ${escapedFileNames}`,
       `eslint --no-ignore --max-warnings=0 --fix ${filenames
-        .map(f => `"${f}"`)
+        .map((f) => `"${f}"`)
         .join(' ')}`,
     ]
   },
-  '**/*.{json,md,mdx,css,html,yml,yaml,scss}': filenames => {
+  '**/*.{json,md,mdx,css,html,yml,yaml,scss}': (filenames) => {
     const escapedFileNames = filenames
-      .map(filename => `"${isWin ? filename : escape([filename])}"`)
+      .map((filename) => `"${isWin ? filename : escape([filename])}"`)
       .join(' ')
     return [
       `prettier --with-node-modules --ignore-path .prettierignore_staged --write ${escapedFileNames}`,
diff --git a/package.json b/package.json
index b787be970c..ec64d26b45 100644
--- a/package.json
+++ b/package.json
@@ -23,8 +23,8 @@
     "lint-eslint": "eslint . --ext js,jsx,ts,tsx --max-warnings=0",
     "lint": "run-p lint-typescript prettier-check lint-eslint",
     "lint-fix": "yarn prettier-fix && eslint . --ext js,jsx,ts,tsx --fix --max-warnings=0",
-    "prettier-check": "prettier --check \"**/*.{js,jsx,json,ts,tsx,md,mdx,css,html,yml,yaml,scss}\"",
-    "prettier-fix": "prettier --write \"**/*.{js,jsx,json,ts,tsx,md,mdx,css,html,yml,yaml,scss}\"",
+    "prettier-check": "prettier --check \"**/*.{js,mjs,cjs,jsx,json,ts,tsx,md,mdx,css,html,yml,yaml,scss,less,graphql,graphqls,gql}\"",
+    "prettier-fix": "prettier --write \"**/*.{js,mjs,cjs,jsx,json,ts,tsx,md,mdx,css,html,yml,yaml,scss,less,graphql,graphqls,gql}\"",
     "types": "lerna run types --stream",
     "typescript": "lerna run typescript",
     "prepublish": "lerna run prepublish",
@@ -97,7 +97,7 @@
     "postcss-short-size": "4.0.0",
     "postcss-trolling": "0.1.7",
     "pre-commit": "1.2.2",
-    "prettier": "1.19.1",
+    "prettier": "2.0.5",
     "react": "16.12.0",
     "react-dom": "16.12.0",
     "react-ssr-prepass": "1.0.8",
diff --git a/packages/create-next-app/create-app.ts b/packages/create-next-app/create-app.ts
index 266d5b5a2b..29da93d2aa 100644
--- a/packages/create-next-app/create-app.ts
+++ b/packages/create-next-app/create-app.ts
@@ -166,7 +166,7 @@ export async function createApp({
     await cpy('**', root, {
       parents: true,
       cwd: path.join(__dirname, 'templates', 'default'),
-      rename: name => {
+      rename: (name) => {
         switch (name) {
           case 'gitignore': {
             return '.'.concat(name)
diff --git a/packages/create-next-app/helpers/examples.ts b/packages/create-next-app/helpers/examples.ts
index c4b70b3643..9a25845dc0 100644
--- a/packages/create-next-app/helpers/examples.ts
+++ b/packages/create-next-app/helpers/examples.ts
@@ -13,7 +13,7 @@ export type RepoInfo = {
 }
 
 export async function isUrlOk(url: string): Promise<boolean> {
-  const res = await got(url).catch(e => e)
+  const res = await got(url).catch((e) => e)
   return res.statusCode === 200
 }
 
@@ -29,7 +29,7 @@ export async function getRepoInfo(
   if (t === undefined) {
     const infoResponse = await got(
       `https://api.github.com/repos/${username}/${name}`
-    ).catch(e => e)
+    ).catch((e) => e)
     if (infoResponse.statusCode !== 200) {
       return
     }
diff --git a/packages/create-next-app/helpers/install.ts b/packages/create-next-app/helpers/install.ts
index 7ba130b211..237f99d787 100644
--- a/packages/create-next-app/helpers/install.ts
+++ b/packages/create-next-app/helpers/install.ts
@@ -40,7 +40,7 @@ export function install(
       stdio: 'inherit',
       env: { ...process.env, ADBLOCK: '1', DISABLE_OPENCOLLECTIVE: '1' },
     })
-    child.on('close', code => {
+    child.on('close', (code) => {
       if (code !== 0) {
         reject({ command: `${command} ${args.join(' ')}` })
         return
diff --git a/packages/create-next-app/helpers/is-folder-empty.ts b/packages/create-next-app/helpers/is-folder-empty.ts
index 4460ce5a5c..05afc387d1 100644
--- a/packages/create-next-app/helpers/is-folder-empty.ts
+++ b/packages/create-next-app/helpers/is-folder-empty.ts
@@ -26,9 +26,9 @@ export function isFolderEmpty(root: string, name: string): boolean {
 
   const conflicts = fs
     .readdirSync(root)
-    .filter(file => !validFiles.includes(file))
+    .filter((file) => !validFiles.includes(file))
     // Support IntelliJ IDEA-based editors
-    .filter(file => !/\.iml$/.test(file))
+    .filter((file) => !/\.iml$/.test(file))
 
   if (conflicts.length > 0) {
     console.log(
diff --git a/packages/create-next-app/helpers/is-online.ts b/packages/create-next-app/helpers/is-online.ts
index aed37e3850..c2f3f83a93 100644
--- a/packages/create-next-app/helpers/is-online.ts
+++ b/packages/create-next-app/helpers/is-online.ts
@@ -8,9 +8,7 @@ function getProxy(): string | undefined {
   }
 
   try {
-    const httpsProxy = execSync('npm config get https-proxy')
-      .toString()
-      .trim()
+    const httpsProxy = execSync('npm config get https-proxy').toString().trim()
     return httpsProxy !== 'null' ? httpsProxy : undefined
   } catch (e) {
     return
@@ -18,8 +16,8 @@ function getProxy(): string | undefined {
 }
 
 export function getOnline(): Promise<boolean> {
-  return new Promise(resolve => {
-    dns.lookup('registry.yarnpkg.com', registryErr => {
+  return new Promise((resolve) => {
+    dns.lookup('registry.yarnpkg.com', (registryErr) => {
       if (!registryErr) {
         return resolve(true)
       }
@@ -34,7 +32,7 @@ export function getOnline(): Promise<boolean> {
         return resolve(false)
       }
 
-      dns.lookup(hostname, proxyErr => {
+      dns.lookup(hostname, (proxyErr) => {
         resolve(proxyErr == null)
       })
     })
diff --git a/packages/create-next-app/index.ts b/packages/create-next-app/index.ts
index cdd111198a..6476129c46 100644
--- a/packages/create-next-app/index.ts
+++ b/packages/create-next-app/index.ts
@@ -17,7 +17,7 @@ const program = new Commander.Command(packageJson.name)
   .version(packageJson.version)
   .arguments('<project-directory>')
   .usage(`${chalk.green('<project-directory>')} [options]`)
-  .action(name => {
+  .action((name) => {
     projectPath = name
   })
   .option('--use-npm')
@@ -54,7 +54,7 @@ async function run(): Promise<void> {
       name: 'path',
       message: 'What is your project named?',
       initial: 'my-app',
-      validate: name => {
+      validate: (name) => {
         const validation = validateNpmName(path.basename(path.resolve(name)))
         if (validation.valid) {
           return true
@@ -95,7 +95,7 @@ async function run(): Promise<void> {
       )} because of npm naming restrictions:`
     )
 
-    problems!.forEach(p => console.error(`    ${chalk.red.bold('*')} ${p}`))
+    problems!.forEach((p) => console.error(`    ${chalk.red.bold('*')} ${p}`))
     process.exit(1)
   }
 
@@ -205,7 +205,7 @@ async function notifyUpdate(): Promise<void> {
 
 run()
   .then(notifyUpdate)
-  .catch(async reason => {
+  .catch(async (reason) => {
     console.log()
     console.log('Aborting installation.')
     if (reason.command) {
diff --git a/packages/eslint-plugin-next/lib/rules/no-css-tags.js b/packages/eslint-plugin-next/lib/rules/no-css-tags.js
index ff1a3411c7..d27cb14e0f 100644
--- a/packages/eslint-plugin-next/lib/rules/no-css-tags.js
+++ b/packages/eslint-plugin-next/lib/rules/no-css-tags.js
@@ -1,4 +1,4 @@
-module.exports = function(context) {
+module.exports = function (context) {
   return {
     JSXOpeningElement(node) {
       if (node.name.name !== 'link') {
@@ -10,10 +10,12 @@ module.exports = function(context) {
 
       if (
         node.attributes.find(
-          attr => attr.name.name === 'rel' && attr.value.value === 'stylesheet'
+          (attr) =>
+            attr.name.name === 'rel' && attr.value.value === 'stylesheet'
         ) &&
         node.attributes.find(
-          attr => attr.name.name === 'href' && !/^https?/.test(attr.value.value)
+          (attr) =>
+            attr.name.name === 'href' && !/^https?/.test(attr.value.value)
         )
       ) {
         context.report({
diff --git a/packages/eslint-plugin-next/lib/rules/no-sync-scripts.js b/packages/eslint-plugin-next/lib/rules/no-sync-scripts.js
index 55e2bfb2c9..f65b5536bb 100644
--- a/packages/eslint-plugin-next/lib/rules/no-sync-scripts.js
+++ b/packages/eslint-plugin-next/lib/rules/no-sync-scripts.js
@@ -1,4 +1,4 @@
-module.exports = function(context) {
+module.exports = function (context) {
   return {
     JSXOpeningElement(node) {
       if (node.name.name !== 'script') {
@@ -9,9 +9,9 @@ module.exports = function(context) {
       }
 
       if (
-        node.attributes.find(attr => attr.name.name === 'src') &&
+        node.attributes.find((attr) => attr.name.name === 'src') &&
         !node.attributes.find(
-          attr => attr.name.name === 'async' || attr.name.name === 'defer'
+          (attr) => attr.name.name === 'async' || attr.name.name === 'defer'
         )
       ) {
         context.report({
diff --git a/packages/next-plugin-google-analytics/src/on-init-client.js b/packages/next-plugin-google-analytics/src/on-init-client.js
index c63f8ed385..094b2c98b2 100644
--- a/packages/next-plugin-google-analytics/src/on-init-client.js
+++ b/packages/next-plugin-google-analytics/src/on-init-client.js
@@ -1,5 +1,5 @@
 export default async function initClient({ router }) {
-  router.events.on('routeChangeComplete', url => {
+  router.events.on('routeChangeComplete', (url) => {
     setTimeout(() => {
       window.gtag('config', process.env.GA_TRACKING_ID, {
         page_location: url,
diff --git a/packages/next-plugin-material-ui/src/unstable-enhance-app-server.js b/packages/next-plugin-material-ui/src/unstable-enhance-app-server.js
index 77f8a335c7..531a864a7b 100644
--- a/packages/next-plugin-material-ui/src/unstable-enhance-app-server.js
+++ b/packages/next-plugin-material-ui/src/unstable-enhance-app-server.js
@@ -3,5 +3,5 @@ import { ServerStyleSheets } from '@material-ui/styles'
 
 export default async function enhanceApp(ctx) {
   ctx.sheets = new ServerStyleSheets()
-  return App => props => ctx.sheets.collect(<App {...props} />)
+  return (App) => (props) => ctx.sheets.collect(<App {...props} />)
 }
diff --git a/packages/next-plugin-storybook/preset.js b/packages/next-plugin-storybook/preset.js
index 4c5c0a27f4..83b84429c4 100644
--- a/packages/next-plugin-storybook/preset.js
+++ b/packages/next-plugin-storybook/preset.js
@@ -25,7 +25,7 @@ async function webpackFinal(config) {
   }
 
   config.module.rules = [
-    ...config.module.rules.filter(rule => {
+    ...config.module.rules.filter((rule) => {
       // the rules we're filtering use RegExp for the test
       if (!rule.test instanceof RegExp) return true
       // use Next.js' built-in CSS
@@ -42,7 +42,7 @@ async function webpackFinal(config) {
       }
       return true
     }),
-    ...nextWebpackConfig.module.rules.map(rule => {
+    ...nextWebpackConfig.module.rules.map((rule) => {
       // we need to resolve next-babel-loader since it's not available
       // relative with storybook's config
       if (rule.use && rule.use.loader === 'next-babel-loader') {
diff --git a/packages/next/bin/next.ts b/packages/next/bin/next.ts
index 20203e3d31..c7e0ff2beb 100755
--- a/packages/next/bin/next.ts
+++ b/packages/next/bin/next.ts
@@ -2,7 +2,7 @@
 import * as log from '../build/output/log'
 import arg from 'next/dist/compiled/arg/index.js'
 import { NON_STANDARD_NODE_ENV } from '../lib/constants'
-;['react', 'react-dom'].forEach(dependency => {
+;['react', 'react-dom'].forEach((dependency) => {
   try {
     // When 'npm link' is used it checks the clone location. Not the project.
     require.resolve(dependency)
@@ -17,13 +17,13 @@ import { NON_STANDARD_NODE_ENV } from '../lib/constants'
 const defaultCommand = 'dev'
 export type cliCommand = (argv?: string[]) => void
 const commands: { [command: string]: () => Promise<cliCommand> } = {
-  build: async () => await import('../cli/next-build').then(i => i.nextBuild),
-  start: async () => await import('../cli/next-start').then(i => i.nextStart),
+  build: async () => await import('../cli/next-build').then((i) => i.nextBuild),
+  start: async () => await import('../cli/next-start').then((i) => i.nextStart),
   export: async () =>
-    await import('../cli/next-export').then(i => i.nextExport),
-  dev: async () => await import('../cli/next-dev').then(i => i.nextDev),
+    await import('../cli/next-export').then((i) => i.nextExport),
+  dev: async () => await import('../cli/next-dev').then((i) => i.nextDev),
   telemetry: async () =>
-    await import('../cli/next-telemetry').then(i => i.nextTelemetry),
+    await import('../cli/next-telemetry').then((i) => i.nextTelemetry),
 }
 
 const args = arg(
@@ -106,7 +106,7 @@ if (typeof React.Suspense === 'undefined') {
   )
 }
 
-commands[command]().then(exec => exec(forwardedArgs))
+commands[command]().then((exec) => exec(forwardedArgs))
 
 if (command === 'dev') {
   const { CONFIG_FILE } = require('../next-server/lib/constants')
diff --git a/packages/next/build/babel/plugins/jsx-pragma.ts b/packages/next/build/babel/plugins/jsx-pragma.ts
index 7362364324..a8b111fb08 100644
--- a/packages/next/build/babel/plugins/jsx-pragma.ts
+++ b/packages/next/build/babel/plugins/jsx-pragma.ts
@@ -1,6 +1,6 @@
 import { NodePath, PluginObj, types as BabelTypes } from '@babel/core'
 
-export default function({
+export default function ({
   types: t,
 }: {
   types: typeof BabelTypes
diff --git a/packages/next/build/babel/plugins/next-data.ts b/packages/next/build/babel/plugins/next-data.ts
index cea1359612..3ec08e62b0 100644
--- a/packages/next/build/babel/plugins/next-data.ts
+++ b/packages/next/build/babel/plugins/next-data.ts
@@ -1,6 +1,6 @@
 import { NodePath, PluginObj, types as BabelTypes } from '@babel/core'
 
-export default function({
+export default function ({
   types: t,
 }: {
   types: typeof BabelTypes
@@ -11,7 +11,7 @@ export default function({
         const source = path.node.source.value
         if (source !== 'next/data') return
 
-        const createHookSpecifier = path.get('specifiers').find(specifier => {
+        const createHookSpecifier = path.get('specifiers').find((specifier) => {
           return (
             specifier.isImportSpecifier() &&
             specifier.node.imported.name === 'createHook'
@@ -27,7 +27,7 @@ export default function({
           return
         }
 
-        binding.referencePaths.forEach(refPath => {
+        binding.referencePaths.forEach((refPath) => {
           let callExpression = refPath.parentPath
 
           if (!callExpression.isCallExpression()) return
diff --git a/packages/next/build/babel/plugins/next-ssg-transform.ts b/packages/next/build/babel/plugins/next-ssg-transform.ts
index 48391584b0..cea149d7cd 100644
--- a/packages/next/build/babel/plugins/next-ssg-transform.ts
+++ b/packages/next/build/babel/plugins/next-ssg-transform.ts
@@ -141,7 +141,7 @@ export default function nextTransformSsg({
         return !b.constantViolations
           .concat(b.referencePaths)
           // Check that every reference is contained within the function:
-          .every(ref => ref.findParent(p => p === b.path))
+          .every((ref) => ref.findParent((p) => p === b.path))
       }
 
       return true
@@ -207,7 +207,7 @@ export default function nextTransformSsg({
               ExportNamedDeclaration(path, state) {
                 const specifiers = path.get('specifiers')
                 if (specifiers.length) {
-                  specifiers.forEach(s => {
+                  specifiers.forEach((s) => {
                     if (isDataIdentifier(s.node.exported.name, state)) {
                       s.remove()
                     }
@@ -239,7 +239,7 @@ export default function nextTransformSsg({
                     const inner = decl.get('declarations') as NodePath<
                       BabelTypes.VariableDeclarator
                     >[]
-                    inner.forEach(d => {
+                    inner.forEach((d) => {
                       if (d.node.id.type !== 'Identifier') {
                         return
                       }
diff --git a/packages/next/build/babel/plugins/optimize-hook-destructuring.ts b/packages/next/build/babel/plugins/optimize-hook-destructuring.ts
index db24591466..17bdb694c5 100644
--- a/packages/next/build/babel/plugins/optimize-hook-destructuring.ts
+++ b/packages/next/build/babel/plugins/optimize-hook-destructuring.ts
@@ -6,7 +6,7 @@ const isHook = /^use[A-Z]/
 // matches only built-in hooks provided by React et al
 const isBuiltInHook = /^use(Callback|Context|DebugValue|Effect|ImperativeHandle|LayoutEffect|Memo|Reducer|Ref|State)$/
 
-export default function({
+export default function ({
   types: t,
 }: {
   types: typeof BabelTypes
@@ -39,7 +39,7 @@ export default function({
         const specifier = (binding.path.parent as BabelTypes.ImportDeclaration)
           .source.value
         // not a match
-        if (!libs.some(lib => lib === specifier)) return
+        if (!libs.some((lib) => lib === specifier)) return
       }
 
       // only match function calls with names that look like a hook
diff --git a/packages/next/build/babel/plugins/react-loadable-plugin.ts b/packages/next/build/babel/plugins/react-loadable-plugin.ts
index 133d239a41..056b416dcd 100644
--- a/packages/next/build/babel/plugins/react-loadable-plugin.ts
+++ b/packages/next/build/babel/plugins/react-loadable-plugin.ts
@@ -25,14 +25,18 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWAR
 
 import { NodePath, PluginObj, types as BabelTypes } from '@babel/core'
 
-export default function({ types: t }: { types: typeof BabelTypes }): PluginObj {
+export default function ({
+  types: t,
+}: {
+  types: typeof BabelTypes
+}): PluginObj {
   return {
     visitor: {
       ImportDeclaration(path: NodePath<BabelTypes.ImportDeclaration>) {
         let source = path.node.source.value
         if (source !== 'next/dynamic') return
 
-        let defaultSpecifier = path.get('specifiers').find(specifier => {
+        let defaultSpecifier = path.get('specifiers').find((specifier) => {
           return specifier.isImportDefaultSpecifier()
         })
 
@@ -45,7 +49,7 @@ export default function({ types: t }: { types: typeof BabelTypes }): PluginObj {
           return
         }
 
-        binding.referencePaths.forEach(refPath => {
+        binding.referencePaths.forEach((refPath) => {
           let callExpression = refPath.parentPath
 
           if (
@@ -100,7 +104,7 @@ export default function({ types: t }: { types: typeof BabelTypes }): PluginObj {
             >
           } = {}
 
-          properties.forEach(property => {
+          properties.forEach((property) => {
             const key: any = property.get('key')
             propertiesMap[key.node.name] = property
           })
@@ -142,7 +146,7 @@ export default function({ types: t }: { types: typeof BabelTypes }): PluginObj {
                   t.arrowFunctionExpression(
                     [],
                     t.arrayExpression(
-                      dynamicImports.map(dynamicImport => {
+                      dynamicImports.map((dynamicImport) => {
                         return t.callExpression(
                           t.memberExpression(
                             t.identifier('require'),
diff --git a/packages/next/build/bundles/autodll-webpack-plugin.js b/packages/next/build/bundles/autodll-webpack-plugin.js
index 981afb0372..e9f117a7ca 100644
--- a/packages/next/build/bundles/autodll-webpack-plugin.js
+++ b/packages/next/build/bundles/autodll-webpack-plugin.js
@@ -1,13 +1,13 @@
 const path = require('path')
 
-module.exports = distDir => {
+module.exports = (distDir) => {
   const autodllCachePath = path.resolve(
     path.join(distDir, 'cache', 'autodll-webpack-plugin')
   )
 
   const autoDllWebpackPluginPaths = require('autodll-webpack-plugin/lib/paths')
   autoDllWebpackPluginPaths.cacheDir = autodllCachePath
-  autoDllWebpackPluginPaths.getManifestPath = hash => bundleName =>
+  autoDllWebpackPluginPaths.getManifestPath = (hash) => (bundleName) =>
     path.resolve(autodllCachePath, hash, `${bundleName}.manifest.json`)
 
   return require('autodll-webpack-plugin')
diff --git a/packages/next/build/entries.ts b/packages/next/build/entries.ts
index 4d811d4f42..c94a1be244 100644
--- a/packages/next/build/entries.ts
+++ b/packages/next/build/entries.ts
@@ -94,7 +94,7 @@ export function createEntrypoints(
     previewProps: JSON.stringify(previewMode),
   }
 
-  Object.keys(pages).forEach(page => {
+  Object.keys(pages).forEach((page) => {
     const absolutePagePath = pages[page]
     const bundleFile = `${normalizePagePath(page)}.js`
     const isApiRoute = page.match(API_ROUTE)
diff --git a/packages/next/build/index.ts b/packages/next/build/index.ts
index bf30f903cb..ed2f249bbd 100644
--- a/packages/next/build/index.ts
+++ b/packages/next/build/index.ts
@@ -169,7 +169,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
     })
   )
 
-  eventNextPlugins(path.resolve(dir)).then(events => telemetry.record(events))
+  eventNextPlugins(path.resolve(dir)).then((events) => telemetry.record(events))
 
   await verifyTypeScriptSetup(dir, pagesDir)
 
@@ -283,7 +283,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
   }
 
   const firstOptionalCatchAllPage =
-    pageKeys.find(f => /\[\[\.{3}[^\][/]*\]\]/.test(f)) ?? null
+    pageKeys.find((f) => /\[\[\.{3}[^\][/]*\]\]/.test(f)) ?? null
   if (
     config.experimental?.optionalCatchAll !== true &&
     firstOptionalCatchAllPage
@@ -297,12 +297,12 @@ export default async function build(dir: string, conf = null): Promise<void> {
     version: 1,
     pages404: true,
     basePath: config.experimental.basePath,
-    redirects: redirects.map(r => buildCustomRoute(r, 'redirect')),
-    rewrites: rewrites.map(r => buildCustomRoute(r, 'rewrite')),
-    headers: headers.map(r => buildCustomRoute(r, 'header')),
+    redirects: redirects.map((r) => buildCustomRoute(r, 'redirect')),
+    rewrites: rewrites.map((r) => buildCustomRoute(r, 'rewrite')),
+    headers: headers.map((r) => buildCustomRoute(r, 'header')),
     dynamicRoutes: getSortedRoutes(pageKeys)
       .filter(isDynamicRoute)
-      .map(page => {
+      .map((page) => {
         const routeRegex = getRouteRegex(page)
         return {
           page,
@@ -497,7 +497,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
 
   const analysisBegin = process.hrtime()
   await Promise.all(
-    pageKeys.map(async page => {
+    pageKeys.map(async (page) => {
       const actualPage = normalizePagePath(page)
       const [selfSize, allSize] = await getJsPageSizeInKb(
         actualPage,
@@ -643,7 +643,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
     routesManifest.dataRoutes = getSortedRoutes([
       ...serverPropsPages,
       ...ssgPages,
-    ]).map(page => {
+    ]).map((page) => {
       const pagePath = normalizePagePath(page)
       const dataRoute = path.posix.join(
         '/_next/data',
@@ -701,7 +701,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
       `Build optimization failed: found page${
         invalidPages.size === 1 ? '' : 's'
       } without a React Component as default export in \n${[...invalidPages]
-        .map(pg => `pages${pg}`)
+        .map((pg) => `pages${pg}`)
         .join(
           '\n'
         )}\n\nSee https://err.sh/zeit/next.js/page-without-valid-component for more info.\n`
@@ -750,7 +750,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
         // server.
         //
         // Note: prerendering disables automatic static optimization.
-        ssgPages.forEach(page => {
+        ssgPages.forEach((page) => {
           if (isDynamicRoute(page)) {
             tbdPrerenderRoutes.push(page)
 
@@ -768,7 +768,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
         // Append the "well-known" routes we should prerender for, e.g. blog
         // post slugs.
         additionalSsgPaths.forEach((routes, page) => {
-          routes.forEach(route => {
+          routes.forEach((route) => {
             defaultMap[route] = { page }
           })
         })
@@ -906,7 +906,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
 
   if (ssgPages.size > 0) {
     const finalDynamicRoutes: PrerenderManifest['dynamicRoutes'] = {}
-    tbdPrerenderRoutes.forEach(tbdRoute => {
+    tbdPrerenderRoutes.forEach((tbdRoute) => {
       const normalizedRoute = normalizePagePath(tbdRoute)
       const dataRoute = path.posix.join(
         '/_next/data',
@@ -967,14 +967,14 @@ export default async function build(dir: string, conf = null): Promise<void> {
     }),
     'utf8'
   )
-  await promises.unlink(path.join(distDir, EXPORT_DETAIL)).catch(err => {
+  await promises.unlink(path.join(distDir, EXPORT_DETAIL)).catch((err) => {
     if (err.code === 'ENOENT') {
       return Promise.resolve()
     }
     return Promise.reject(err)
   })
 
-  staticPages.forEach(pg => allStaticPages.add(pg))
+  staticPages.forEach((pg) => allStaticPages.add(pg))
   pageInfos.forEach((info: PageInfo, key: string) => {
     allPageInfos.set(key, info)
   })
@@ -997,7 +997,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
 
   if (tracer) {
     const parsedResults = await tracer.profiler.stopProfiling()
-    await new Promise(resolve => {
+    await new Promise((resolve) => {
       if (parsedResults === undefined) {
         tracer.profiler.destroy()
         tracer.trace.flush()
@@ -1077,11 +1077,13 @@ function generateClientSsgManifest(
     isModern && '_ssgManifest.module.js',
   ]
     .filter(Boolean)
-    .map(f => path.join(`${CLIENT_STATIC_FILES_PATH}/${buildId}`, f as string))
+    .map((f) =>
+      path.join(`${CLIENT_STATIC_FILES_PATH}/${buildId}`, f as string)
+    )
   const clientSsgManifestContent = `self.__SSG_MANIFEST=${devalue(
     ssgPages
   )};self.__SSG_MANIFEST_CB&&self.__SSG_MANIFEST_CB()`
-  clientSsgManifestPaths.forEach(clientSsgManifestPath =>
+  clientSsgManifestPaths.forEach((clientSsgManifestPath) =>
     writeFileSync(
       path.join(distDir, clientSsgManifestPath),
       clientSsgManifestContent
diff --git a/packages/next/build/output/index.ts b/packages/next/build/output/index.ts
index 1d089b8ea2..49002b1ab9 100644
--- a/packages/next/build/output/index.ts
+++ b/packages/next/build/output/index.ts
@@ -120,7 +120,7 @@ export function formatAmpMessages(amp: AmpPageStatus) {
 
 const buildStore = createStore<BuildStatusStore>()
 
-buildStore.subscribe(state => {
+buildStore.subscribe((state) => {
   const { amp, client, server } = state
 
   const [{ status }] = [
@@ -175,7 +175,7 @@ export function ampValidation(
   if (!(errors.length || warnings.length)) {
     buildStore.setState({
       amp: Object.keys(amp)
-        .filter(k => k !== page)
+        .filter((k) => k !== page)
         .sort()
         // eslint-disable-next-line no-sequences
         .reduce((a, c) => ((a[c] = amp[c]), a), {} as AmpPageStatus),
@@ -235,10 +235,10 @@ export function watchCompilers(
     )
   }
 
-  tapCompiler('client', client, status =>
+  tapCompiler('client', client, (status) =>
     buildStore.setState({ client: status })
   )
-  tapCompiler('server', server, status =>
+  tapCompiler('server', server, (status) =>
     buildStore.setState({ server: status })
   )
 
diff --git a/packages/next/build/output/store.ts b/packages/next/build/output/store.ts
index b982f26477..ad2eb1558f 100644
--- a/packages/next/build/output/store.ts
+++ b/packages/next/build/output/store.ts
@@ -22,7 +22,7 @@ function hasStoreChanged(nextStore: OutputState) {
   if (
     ([
       ...new Set([...Object.keys(lastStore), ...Object.keys(nextStore)]),
-    ] as Array<keyof OutputState>).every(key =>
+    ] as Array<keyof OutputState>).every((key) =>
       Object.is(lastStore[key], nextStore[key])
     )
   ) {
@@ -33,7 +33,7 @@ function hasStoreChanged(nextStore: OutputState) {
   return true
 }
 
-store.subscribe(state => {
+store.subscribe((state) => {
   if (!hasStoreChanged(state)) {
     return
   }
diff --git a/packages/next/build/plugins/collect-plugins.ts b/packages/next/build/plugins/collect-plugins.ts
index a2e109b1e9..add0988004 100644
--- a/packages/next/build/plugins/collect-plugins.ts
+++ b/packages/next/build/plugins/collect-plugins.ts
@@ -73,7 +73,7 @@ async function collectPluginMeta(
   }
 
   // remove the extension from the middleware
-  middleware = middleware.map(item => {
+  middleware = middleware.map((item) => {
     const parts = item.split('.')
     parts.pop()
     return parts.join('.')
@@ -158,7 +158,7 @@ async function _collectPlugins(
   const hasPluginConfig = Array.isArray(pluginsConfig)
 
   const nextPluginConfigNames = hasPluginConfig
-    ? pluginsConfig!.map(config =>
+    ? pluginsConfig!.map((config) =>
         typeof config === 'string' ? config : config.name
       )
     : null
@@ -188,7 +188,7 @@ async function _collectPlugins(
     // @scope/next-plugin-[name]
     // @next/plugin-[name]
     // next-plugin-[name]
-    const filteredDeps = dependencies.filter(name => {
+    const filteredDeps = dependencies.filter((name) => {
       return name.match(/(^@next\/plugin|next-plugin-)/)
     })
 
@@ -205,7 +205,7 @@ async function _collectPlugins(
   }
 
   const nextPluginMetaData = await Promise.all(
-    nextPluginNames.map(name =>
+    nextPluginNames.map((name) =>
       collectPluginMeta(
         env,
         resolve.sync(path.join(name, 'package.json'), {
@@ -220,7 +220,7 @@ async function _collectPlugins(
     // Add plugin config from `next.config.js`
     if (hasPluginConfig) {
       const curPlugin = pluginsConfig!.find(
-        config =>
+        (config) =>
           config && typeof config === 'object' && config.name === plugin.pkgName
       )
       if (curPlugin && typeof curPlugin === 'object') {
diff --git a/packages/next/build/polyfills/object.assign/polyfill.js b/packages/next/build/polyfills/object.assign/polyfill.js
index 5aa03fb905..c328e36acc 100644
--- a/packages/next/build/polyfills/object.assign/polyfill.js
+++ b/packages/next/build/polyfills/object.assign/polyfill.js
@@ -1,3 +1,3 @@
-module.exports = function() {
+module.exports = function () {
   return Object.assign
 }
diff --git a/packages/next/build/polyfills/object.assign/shim.js b/packages/next/build/polyfills/object.assign/shim.js
index 5aa03fb905..c328e36acc 100644
--- a/packages/next/build/polyfills/object.assign/shim.js
+++ b/packages/next/build/polyfills/object.assign/shim.js
@@ -1,3 +1,3 @@
-module.exports = function() {
+module.exports = function () {
   return Object.assign
 }
diff --git a/packages/next/build/profiler/profiler.js b/packages/next/build/profiler/profiler.js
index ffaa00f2d8..0ddbeb4b46 100644
--- a/packages/next/build/profiler/profiler.js
+++ b/packages/next/build/profiler/profiler.js
@@ -84,7 +84,7 @@ const { Tracer } = require('chrome-trace-event')
  * @param {string} outputPath The location where to write the log.
  * @returns {Trace} The trace object
  */
-export const createTrace = outputPath => {
+export const createTrace = (outputPath) => {
   const trace = new Tracer({
     noStream: true,
   })
@@ -134,7 +134,7 @@ export const createTrace = outputPath => {
     trace,
     counter,
     profiler,
-    end: callback => {
+    end: (callback) => {
       // Wait until the write stream finishes.
       fsStream.on('finish', () => {
         callback()
diff --git a/packages/next/build/utils.ts b/packages/next/build/utils.ts
index e02e7d902b..d6ce4e8537 100644
--- a/packages/next/build/utils.ts
+++ b/packages/next/build/utils.ts
@@ -89,11 +89,9 @@ export async function printTreeView(
       .replace(/[.-]([0-9a-z]{6})[0-9a-z]{14}(?=\.)/, '.$1')
 
   const messages: [string, string, string][] = [
-    ['Page', 'Size', 'First Load JS'].map(entry => chalk.underline(entry)) as [
-      string,
-      string,
-      string
-    ],
+    ['Page', 'Size', 'First Load JS'].map((entry) =>
+      chalk.underline(entry)
+    ) as [string, string, string],
   ]
 
   const hasCustomApp = await findPageFile(pagesDir, '/_app', pageExtensions)
@@ -118,7 +116,7 @@ export async function printTreeView(
   const pageList = list
     .slice()
     .filter(
-      e =>
+      (e) =>
         !(
           e === '/_document' ||
           e === '/_error' ||
@@ -167,7 +165,7 @@ export async function printTreeView(
 
     const uniqueCssFiles =
       buildManifest.pages[item]?.filter(
-        file => file.endsWith('.css') && sizeData.uniqueFiles.includes(file)
+        (file) => file.endsWith('.css') && sizeData.uniqueFiles.includes(file)
       ) || []
 
     if (uniqueCssFiles.length > 0) {
@@ -213,16 +211,16 @@ export async function printTreeView(
   const sharedCssFiles: string[] = []
   ;[
     ...sharedFileKeys
-      .filter(file => {
+      .filter((file) => {
         if (file.endsWith('.css')) {
           sharedCssFiles.push(file)
           return false
         }
         return true
       })
-      .map(e => e.replace(buildId, '<buildId>'))
+      .map((e) => e.replace(buildId, '<buildId>'))
       .sort(),
-    ...sharedCssFiles.map(e => e.replace(buildId, '<buildId>')).sort(),
+    ...sharedCssFiles.map((e) => e.replace(buildId, '<buildId>')).sort(),
   ].forEach((fileName, index, { length }) => {
     const innerSymbol = index === length - 1 ? '└' : '├'
 
@@ -239,7 +237,7 @@ export async function printTreeView(
   console.log(
     textTable(messages, {
       align: ['l', 'l', 'r'],
-      stringLength: str => stripAnsi(str).length,
+      stringLength: (str) => stripAnsi(str).length,
     })
   )
 
@@ -269,7 +267,7 @@ export async function printTreeView(
       ] as [string, string, string][],
       {
         align: ['l', 'l', 'l'],
-        stringLength: str => stripAnsi(str).length,
+        stringLength: (str) => stripAnsi(str).length,
       }
     )
   )
@@ -381,7 +379,7 @@ async function computeFromManifest(
 
   let expected = 0
   const files = new Map<string, number>()
-  Object.keys(manifest.pages).forEach(key => {
+  Object.keys(manifest.pages).forEach((key) => {
     // prevent duplicate '/' and '/index'
     if (key === '/index') return
 
@@ -399,7 +397,7 @@ async function computeFromManifest(
     }
 
     ++expected
-    manifest.pages[key].forEach(file => {
+    manifest.pages[key].forEach((file) => {
       if (
         // Select Modern or Legacy scripts
         file.endsWith('.module.js') !== isModern
@@ -437,7 +435,7 @@ async function computeFromManifest(
   try {
     stats = await Promise.all(
       commonFiles.map(
-        async f =>
+        async (f) =>
           [f, await fsStatGzip(path.join(distPath, f))] as [string, number]
       )
     )
@@ -449,7 +447,7 @@ async function computeFromManifest(
   try {
     uniqueStats = await Promise.all(
       uniqueFiles.map(
-        async f =>
+        async (f) =>
           [f, await fsStatGzip(path.join(distPath, f))] as [string, number]
       )
     )
@@ -483,13 +481,13 @@ async function computeFromManifest(
 function difference<T>(main: T[], sub: T[]): T[] {
   const a = new Set(main)
   const b = new Set(sub)
-  return [...a].filter(x => !b.has(x))
+  return [...a].filter((x) => !b.has(x))
 }
 
 function intersect<T>(main: T[], sub: T[]): T[] {
   const a = new Set(main)
   const b = new Set(sub)
-  return [...new Set([...a].filter(x => b.has(x)))]
+  return [...new Set([...a].filter((x) => b.has(x)))]
 }
 
 function sum(a: number[]): number {
@@ -580,7 +578,7 @@ export async function buildStaticPaths(
   }
 
   const invalidStaticPathKeys = Object.keys(staticPathsResult).filter(
-    key => !(key === 'paths' || key === 'fallback')
+    (key) => !(key === 'paths' || key === 'fallback')
   )
 
   if (invalidStaticPathKeys.length > 0) {
@@ -607,7 +605,7 @@ export async function buildStaticPaths(
     )
   }
 
-  toPrerender.forEach(entry => {
+  toPrerender.forEach((entry) => {
     // For a string-provided path, we must make sure it matches the dynamic
     // route.
     if (typeof entry === 'string') {
@@ -623,13 +621,13 @@ export async function buildStaticPaths(
     // For the object-provided path, we must make sure it specifies all
     // required keys.
     else {
-      const invalidKeys = Object.keys(entry).filter(key => key !== 'params')
+      const invalidKeys = Object.keys(entry).filter((key) => key !== 'params')
       if (invalidKeys.length) {
         throw new Error(
           `Additional keys were returned from \`getStaticPaths\` in page "${page}". ` +
             `URL Parameters intended for this dynamic route must be nested under the \`params\` key, i.e.:` +
             `\n\n\treturn { params: { ${_validParamKeys
-              .map(k => `${k}: ...`)
+              .map((k) => `${k}: ...`)
               .join(', ')} } }` +
             `\n\nKeys that need to be moved: ${invalidKeys.join(', ')}.\n`
         )
@@ -637,7 +635,7 @@ export async function buildStaticPaths(
 
       const { params = {} } = entry
       let builtPage = page
-      _validParamKeys.forEach(validParamKey => {
+      _validParamKeys.forEach((validParamKey) => {
         const { repeat } = _routeRegex.groups[validParamKey]
         const paramValue = params[validParamKey]
         if (
diff --git a/packages/next/build/webpack-config.ts b/packages/next/build/webpack-config.ts
index 7257191b54..f1ad5ff1ca 100644
--- a/packages/next/build/webpack-config.ts
+++ b/packages/next/build/webpack-config.ts
@@ -201,14 +201,14 @@ export default async function getBaseWebpackConfig(
     /next[\\/]dist[\\/]pages/,
     /[\\/](strip-ansi|ansi-regex)[\\/]/,
     ...(config.experimental.plugins
-      ? VALID_MIDDLEWARE.map(name => new RegExp(`src(\\\\|/)${name}`))
+      ? VALID_MIDDLEWARE.map((name) => new RegExp(`src(\\\\|/)${name}`))
       : []),
   ]
 
   // Support for NODE_PATH
   const nodePathList = (process.env.NODE_PATH || '')
     .split(process.platform === 'win32' ? ';' : ':')
-    .filter(p => !!p)
+    .filter((p) => !!p)
 
   const isServerless = target === 'serverless'
   const isServerlessTrace = target === 'experimental-serverless-trace'
@@ -756,7 +756,7 @@ export default async function getBaseWebpackConfig(
           test: /\.(tsx|ts|js|mjs|jsx)$/,
           include: [dir, ...babelIncludeRegexes],
           exclude: (path: string) => {
-            if (babelIncludeRegexes.some(r => r.test(path))) {
+            if (babelIncludeRegexes.some((r) => r.test(path))) {
               return false
             }
             return /node_modules/.test(path)
@@ -1085,13 +1085,13 @@ export default async function getBaseWebpackConfig(
       '/tmp/test.styl',
     ]
 
-    if (rule instanceof RegExp && fileNames.some(input => rule.test(input))) {
+    if (rule instanceof RegExp && fileNames.some((input) => rule.test(input))) {
       return true
     }
 
     if (typeof rule === 'function') {
       if (
-        fileNames.some(input => {
+        fileNames.some((input) => {
           try {
             if (rule(input)) {
               return true
@@ -1113,7 +1113,7 @@ export default async function getBaseWebpackConfig(
 
   const hasUserCssConfig =
     webpackConfig.module?.rules.some(
-      rule => canMatchCss(rule.test) || canMatchCss(rule.include)
+      (rule) => canMatchCss(rule.test) || canMatchCss(rule.include)
     ) ?? false
 
   if (hasUserCssConfig) {
@@ -1131,7 +1131,7 @@ export default async function getBaseWebpackConfig(
     if (webpackConfig.module?.rules.length) {
       // Remove default CSS Loader
       webpackConfig.module.rules = webpackConfig.module.rules.filter(
-        r =>
+        (r) =>
           !(
             typeof r.oneOf?.[0]?.options === 'object' &&
             r.oneOf[0].options.__next_css_remove === true
@@ -1141,13 +1141,13 @@ export default async function getBaseWebpackConfig(
     if (webpackConfig.plugins?.length) {
       // Disable CSS Extraction Plugin
       webpackConfig.plugins = webpackConfig.plugins.filter(
-        p => (p as any).__next_css_remove !== true
+        (p) => (p as any).__next_css_remove !== true
       )
     }
     if (webpackConfig.optimization?.minimizer?.length) {
       // Disable CSS Minifier
       webpackConfig.optimization.minimizer = webpackConfig.optimization.minimizer.filter(
-        e => (e as any).__next_css_remove !== true
+        (e) => (e as any).__next_css_remove !== true
       )
     }
   } else {
@@ -1183,7 +1183,7 @@ export default async function getBaseWebpackConfig(
 
   // Patch `@zeit/next-sass`, `@zeit/next-less`, `@zeit/next-stylus` for compatibility
   if (webpackConfig.module && Array.isArray(webpackConfig.module.rules)) {
-    ;[].forEach.call(webpackConfig.module.rules, function(
+    ;[].forEach.call(webpackConfig.module.rules, function (
       rule: webpack.RuleSetRule
     ) {
       if (!(rule.test instanceof RegExp && Array.isArray(rule.use))) {
@@ -1201,7 +1201,7 @@ export default async function getBaseWebpackConfig(
         return
       }
 
-      ;[].forEach.call(rule.use, function(use: webpack.RuleSetUseItem) {
+      ;[].forEach.call(rule.use, function (use: webpack.RuleSetUseItem) {
         if (
           !(
             use &&
diff --git a/packages/next/build/webpack/config/blocks/css/loaders/client.ts b/packages/next/build/webpack/config/blocks/css/loaders/client.ts
index ab3024c05c..0153be231b 100644
--- a/packages/next/build/webpack/config/blocks/css/loaders/client.ts
+++ b/packages/next/build/webpack/config/blocks/css/loaders/client.ts
@@ -17,7 +17,7 @@ export function getClientStyleLoader({
           // and prod. To fix this, we render a <noscript> tag as
           // an anchor for the styles to be placed before. These
           // styles will be applied _before_ <style jsx global>.
-          insert: function(element: Node) {
+          insert: function (element: Node) {
             // These elements should always exist. If they do not,
             // this code should fail.
             var anchorElement = document.querySelector(
@@ -38,7 +38,7 @@ export function getClientStyleLoader({
             // We use `requestAnimationFrame` as a way to defer
             // this operation since there may be multiple style
             // tags.
-            ;(self.requestAnimationFrame || setTimeout)(function() {
+            ;(self.requestAnimationFrame || setTimeout)(function () {
               for (
                 var x = document.querySelectorAll('[data-next-hide-fouc]'),
                   i = x.length;
diff --git a/packages/next/build/webpack/config/blocks/css/overrideCssConfiguration.ts b/packages/next/build/webpack/config/blocks/css/overrideCssConfiguration.ts
index 5d36386181..ee27408a35 100644
--- a/packages/next/build/webpack/config/blocks/css/overrideCssConfiguration.ts
+++ b/packages/next/build/webpack/config/blocks/css/overrideCssConfiguration.ts
@@ -18,7 +18,7 @@ export async function __overrideCssConfiguration(
     } else if (Array.isArray(rule.oneOf)) {
       rule.oneOf.forEach(patch)
     } else if (Array.isArray(rule.use)) {
-      rule.use.forEach(u => {
+      rule.use.forEach((u) => {
         if (typeof u === 'object') {
           patch(u)
         }
@@ -26,7 +26,7 @@ export async function __overrideCssConfiguration(
     }
   }
 
-  config.module?.rules?.forEach(entry => {
+  config.module?.rules?.forEach((entry) => {
     patch(entry)
   })
 }
diff --git a/packages/next/build/webpack/config/blocks/css/plugins.ts b/packages/next/build/webpack/config/blocks/css/plugins.ts
index 032badee4b..39046cfab4 100644
--- a/packages/next/build/webpack/config/blocks/css/plugins.ts
+++ b/packages/next/build/webpack/config/blocks/css/plugins.ts
@@ -125,7 +125,7 @@ export async function getPostCssPlugins(
   }
 
   // Warn user about configuration keys which are not respected
-  const invalidKey = Object.keys(config).find(key => key !== 'plugins')
+  const invalidKey = Object.keys(config).find((key) => key !== 'plugins')
   if (invalidKey) {
     console.warn(
       `${chalk.yellow.bold(
@@ -160,7 +160,7 @@ export async function getPostCssPlugins(
   }
 
   const parsed: CssPluginShape[] = []
-  plugins.forEach(plugin => {
+  plugins.forEach((plugin) => {
     if (plugin == null) {
       console.warn(
         `${chalk.yellow.bold('Warning')}: A ${chalk.bold(
@@ -218,7 +218,7 @@ export async function getPostCssPlugins(
   })
 
   const resolved = await Promise.all(
-    parsed.map(p => loadPlugin(dir, p[0], p[1]))
+    parsed.map((p) => loadPlugin(dir, p[0], p[1]))
   )
   const filtered: import('postcss').AcceptedPlugin[] = resolved.filter(
     Boolean
diff --git a/packages/next/build/webpack/config/helpers.ts b/packages/next/build/webpack/config/helpers.ts
index 67edf14648..26995dda10 100644
--- a/packages/next/build/webpack/config/helpers.ts
+++ b/packages/next/build/webpack/config/helpers.ts
@@ -10,7 +10,7 @@ export const loader = curry(function loader(
   }
 
   if (rule.oneOf) {
-    const existing = config.module.rules.find(rule => rule.oneOf)
+    const existing = config.module.rules.find((rule) => rule.oneOf)
     if (existing) {
       existing.oneOf!.push(...rule.oneOf)
       return config
@@ -30,7 +30,7 @@ export const unshiftLoader = curry(function loader(
   }
 
   if (rule.oneOf) {
-    const existing = config.module.rules.find(rule => rule.oneOf)
+    const existing = config.module.rules.find((rule) => rule.oneOf)
     if (existing) {
       existing.oneOf!.unshift(...rule.oneOf)
       return config
diff --git a/packages/next/build/webpack/loaders/emit-file-loader.js b/packages/next/build/webpack/loaders/emit-file-loader.js
index efd8db7221..a1b1e44e05 100644
--- a/packages/next/build/webpack/loaders/emit-file-loader.js
+++ b/packages/next/build/webpack/loaders/emit-file-loader.js
@@ -1,6 +1,6 @@
 import loaderUtils from 'loader-utils'
 
-module.exports = function(content, sourceMap) {
+module.exports = function (content, sourceMap) {
   this.cacheable()
   const callback = this.async()
   const resourcePath = this.resourcePath
@@ -21,7 +21,7 @@ module.exports = function(content, sourceMap) {
   const context = query.context || this.rootContext || this.options.context
   const regExp = query.regExp
   const opts = { context, content, regExp }
-  const interpolateName = query.interpolateName || (name => name)
+  const interpolateName = query.interpolateName || ((name) => name)
   const interpolatedName = interpolateName(
     loaderUtils.interpolateName(this, name, opts),
     { name, opts }
diff --git a/packages/next/build/webpack/loaders/error-loader.ts b/packages/next/build/webpack/loaders/error-loader.ts
index 1febd13963..9e99b8f37f 100644
--- a/packages/next/build/webpack/loaders/error-loader.ts
+++ b/packages/next/build/webpack/loaders/error-loader.ts
@@ -3,7 +3,7 @@ import loaderUtils from 'loader-utils'
 import path from 'path'
 import { loader } from 'webpack'
 
-const ErrorLoader: loader.Loader = function() {
+const ErrorLoader: loader.Loader = function () {
   const options = loaderUtils.getOptions(this) || {}
 
   const { reason = 'An unknown error has occurred' } = options
diff --git a/packages/next/build/webpack/loaders/next-babel-loader.js b/packages/next/build/webpack/loaders/next-babel-loader.js
index 0a49f6f911..747375c0f1 100644
--- a/packages/next/build/webpack/loaders/next-babel-loader.js
+++ b/packages/next/build/webpack/loaders/next-babel-loader.js
@@ -32,10 +32,10 @@ const getModernOptions = (babelOptions = {}) => {
   }
 }
 
-const nextBabelPresetModern = presetOptions => context =>
+const nextBabelPresetModern = (presetOptions) => (context) =>
   nextBabelPreset(context, getModernOptions(presetOptions))
 
-module.exports = babelLoader.custom(babel => {
+module.exports = babelLoader.custom((babel) => {
   const presetItem = babel.createConfigItem(nextBabelPreset, {
     type: 'preset',
   })
@@ -168,11 +168,11 @@ module.exports = babelLoader.custom(babel => {
 
       if (isModern) {
         const nextPreset = options.presets.find(
-          preset => preset && preset.value === nextBabelPreset
+          (preset) => preset && preset.value === nextBabelPreset
         ) || { options: {} }
 
         const additionalPresets = options.presets.filter(
-          preset => preset !== nextPreset
+          (preset) => preset !== nextPreset
         )
 
         const presetItemModern = babel.createConfigItem(
diff --git a/packages/next/build/webpack/loaders/next-client-pages-loader.ts b/packages/next/build/webpack/loaders/next-client-pages-loader.ts
index 1123b08f75..3d338cabb0 100644
--- a/packages/next/build/webpack/loaders/next-client-pages-loader.ts
+++ b/packages/next/build/webpack/loaders/next-client-pages-loader.ts
@@ -6,7 +6,7 @@ export type ClientPagesLoaderOptions = {
   page: string
 }
 
-const nextClientPagesLoader: loader.Loader = function() {
+const nextClientPagesLoader: loader.Loader = function () {
   const { absolutePagePath, page } = loaderUtils.getOptions(
     this
   ) as ClientPagesLoaderOptions
diff --git a/packages/next/build/webpack/loaders/next-data-loader.ts b/packages/next/build/webpack/loaders/next-data-loader.ts
index d6cc48ba85..c17f1d778b 100644
--- a/packages/next/build/webpack/loaders/next-data-loader.ts
+++ b/packages/next/build/webpack/loaders/next-data-loader.ts
@@ -1,7 +1,7 @@
 import { loader } from 'webpack'
 import hash from 'next/dist/compiled/string-hash'
 import { basename } from 'path'
-const nextDataLoader: loader.Loader = function(source) {
+const nextDataLoader: loader.Loader = function (source) {
   const filename = this.resourcePath
   return `
   import {createHook} from 'next/data'
diff --git a/packages/next/build/webpack/loaders/next-plugin-loader.ts b/packages/next/build/webpack/loaders/next-plugin-loader.ts
index d30f15f927..9d9e8ef188 100644
--- a/packages/next/build/webpack/loaders/next-plugin-loader.ts
+++ b/packages/next/build/webpack/loaders/next-plugin-loader.ts
@@ -12,11 +12,11 @@ export const pluginLoaderOptions: {
   plugins: [],
 }
 
-const nextPluginLoader: loader.Loader = function(source) {
+const nextPluginLoader: loader.Loader = function (source) {
   const { middleware }: NextPluginLoaderQuery =
     typeof this.query === 'string' ? parse(this.query.substr(1)) : this.query
 
-  const plugins = pluginLoaderOptions.plugins.filter(plugin => {
+  const plugins = pluginLoaderOptions.plugins.filter((plugin) => {
     return plugin.middleware.includes(middleware)
   })
 
@@ -25,7 +25,7 @@ const nextPluginLoader: loader.Loader = function(source) {
 
   return `
     ${plugins
-      .map(plugin => {
+      .map((plugin) => {
         const pluginId = getPluginId(plugin.pkgName)
         pluginIds.push(pluginId)
         pluginConfigs.push(plugin.config || {})
diff --git a/packages/next/build/webpack/loaders/next-serverless-loader.ts b/packages/next/build/webpack/loaders/next-serverless-loader.ts
index fced4aa6aa..930dd7d60d 100644
--- a/packages/next/build/webpack/loaders/next-serverless-loader.ts
+++ b/packages/next/build/webpack/loaders/next-serverless-loader.ts
@@ -28,7 +28,7 @@ export type ServerlessLoaderQuery = {
   previewProps: string
 }
 
-const nextServerlessLoader: loader.Loader = function() {
+const nextServerlessLoader: loader.Loader = function () {
   const {
     distDir,
     absolutePagePath,
diff --git a/packages/next/build/webpack/loaders/noop-loader.ts b/packages/next/build/webpack/loaders/noop-loader.ts
index b44453b0c2..c8dde089f1 100644
--- a/packages/next/build/webpack/loaders/noop-loader.ts
+++ b/packages/next/build/webpack/loaders/noop-loader.ts
@@ -1,4 +1,4 @@
 import { loader } from 'webpack'
 
-const NoopLoader: loader.Loader = source => source
+const NoopLoader: loader.Loader = (source) => source
 export default NoopLoader
diff --git a/packages/next/build/webpack/plugins/build-manifest-plugin.ts b/packages/next/build/webpack/plugins/build-manifest-plugin.ts
index c6950cf1fc..ed577e7213 100644
--- a/packages/next/build/webpack/plugins/build-manifest-plugin.ts
+++ b/packages/next/build/webpack/plugins/build-manifest-plugin.ts
@@ -26,7 +26,7 @@ const generateClientManifest = (
     // Filter out dependencies in the _app entry, because those will have already
     // been loaded by the client prior to a navigation event
     const filteredDeps = dependencies.filter(
-      dep =>
+      (dep) =>
         !appDependencies.has(dep) &&
         (!dep.endsWith('.js') || dep.endsWith('.module.js') === isModern)
     )
@@ -68,7 +68,7 @@ export default class BuildManifestPlugin {
         }
 
         const mainJsChunk = chunks.find(
-          c => c.name === CLIENT_STATIC_FILES_RUNTIME_MAIN
+          (c) => c.name === CLIENT_STATIC_FILES_RUNTIME_MAIN
         )
         const mainJsFiles: string[] =
           mainJsChunk && mainJsChunk.files.length > 0
@@ -76,12 +76,12 @@ export default class BuildManifestPlugin {
             : []
 
         const polyfillChunk = chunks.find(
-          c => c.name === CLIENT_STATIC_FILES_RUNTIME_POLYFILLS
+          (c) => c.name === CLIENT_STATIC_FILES_RUNTIME_POLYFILLS
         )
         const polyfillFiles: string[] = polyfillChunk ? polyfillChunk.files : []
 
         const reactRefreshChunk = chunks.find(
-          c => c.name === CLIENT_STATIC_FILES_RUNTIME_REACT_REFRESH
+          (c) => c.name === CLIENT_STATIC_FILES_RUNTIME_REACT_REFRESH
         )
         assetMap.devFiles.push(...(reactRefreshChunk?.files ?? []))
 
diff --git a/packages/next/build/webpack/plugins/css-minimizer-plugin.ts b/packages/next/build/webpack/plugins/css-minimizer-plugin.ts
index 11afbbbccc..b8d4995dc9 100644
--- a/packages/next/build/webpack/plugins/css-minimizer-plugin.ts
+++ b/packages/next/build/webpack/plugins/css-minimizer-plugin.ts
@@ -21,18 +21,18 @@ export class CssMinimizerPlugin {
   }
 
   apply(compiler: webpack.Compiler) {
-    compiler.hooks.compilation.tap('CssMinimizerPlugin', compilation => {
+    compiler.hooks.compilation.tap('CssMinimizerPlugin', (compilation) => {
       compilation.hooks.optimizeChunkAssets.tapPromise(
         'CssMinimizerPlugin',
-        chunks =>
+        (chunks) =>
           Promise.all(
             chunks
               .reduce(
                 (acc, chunk) => acc.concat(chunk.files || []),
                 [] as string[]
               )
-              .filter(entry => CSS_REGEX.test(entry))
-              .map(file => {
+              .filter((entry) => CSS_REGEX.test(entry))
+              .map((file) => {
                 const postcssOptions = {
                   ...this.options.postcssOptions,
                   to: file,
@@ -50,7 +50,7 @@ export class CssMinimizerPlugin {
                   input = asset.source()
                 }
 
-                return minify(input, postcssOptions).then(res => {
+                return minify(input, postcssOptions).then((res) => {
                   if (res.map) {
                     compilation.assets[file] = new SourceMapSource(
                       res.css,
diff --git a/packages/next/build/webpack/plugins/jsconfig-paths-plugin.ts b/packages/next/build/webpack/plugins/jsconfig-paths-plugin.ts
index 248517a893..f08089feb4 100644
--- a/packages/next/build/webpack/plugins/jsconfig-paths-plugin.ts
+++ b/packages/next/build/webpack/plugins/jsconfig-paths-plugin.ts
@@ -102,7 +102,7 @@ export function matchPatternOrExact(
     }
   }
 
-  return findBestPatternMatch(patterns, _ => _, candidate)
+  return findBestPatternMatch(patterns, (_) => _, candidate)
 }
 
 /**
@@ -212,7 +212,7 @@ export class JsConfigPathsPlugin implements ResolvePlugin {
             }
 
             const candidate = path.join(baseDirectory, curPath)
-            const [err, result] = await new Promise(resolve => {
+            const [err, result] = await new Promise((resolve) => {
               const obj = Object.assign({}, request, {
                 request: candidate,
               })
diff --git a/packages/next/build/webpack/plugins/next-drop-client-page-plugin.ts b/packages/next/build/webpack/plugins/next-drop-client-page-plugin.ts
index f7d572e8fa..ba14992c80 100644
--- a/packages/next/build/webpack/plugins/next-drop-client-page-plugin.ts
+++ b/packages/next/build/webpack/plugins/next-drop-client-page-plugin.ts
@@ -6,8 +6,8 @@ export class DropClientPage implements Plugin {
   ampPages = new Set()
 
   apply(compiler: Compiler) {
-    compiler.hooks.emit.tap('DropClientPage', compilation => {
-      Object.keys(compilation.assets).forEach(assetKey => {
+    compiler.hooks.emit.tap('DropClientPage', (compilation) => {
+      Object.keys(compilation.assets).forEach((assetKey) => {
         const asset = compilation.assets[assetKey]
 
         if (asset?._value?.includes?.('__NEXT_DROP_CLIENT_FILE__')) {
diff --git a/packages/next/build/webpack/plugins/next-esm-plugin.ts b/packages/next/build/webpack/plugins/next-esm-plugin.ts
index 91a6f21b4a..52a1b58c8d 100644
--- a/packages/next/build/webpack/plugins/next-esm-plugin.ts
+++ b/packages/next/build/webpack/plugins/next-esm-plugin.ts
@@ -96,7 +96,7 @@ export default class NextEsmPlugin implements Plugin {
     for (let rule of rules) {
       if (Array.isArray(rule.use)) {
         const matches = (rule.use as RuleSetLoader[]).filter(
-          r => r.loader && predicate(r.loader)
+          (r) => r.loader && predicate(r.loader)
         )
         if (matches.length > 0) {
           results.push(...matches)
@@ -125,7 +125,7 @@ export default class NextEsmPlugin implements Plugin {
 
     let babelLoader = this.getLoaders(
       childCompiler.options.module.rules,
-      loader => loader.includes('next-babel-loader')
+      (loader) => loader.includes('next-babel-loader')
     )[0]
 
     if (!babelLoader) {
@@ -141,7 +141,7 @@ export default class NextEsmPlugin implements Plugin {
 
     const additionalBabelLoaders = this.getLoaders(
       childCompiler.options.module.rules,
-      loader => /(^|[\\/])babel-loader([\\/]|$)/.test(loader)
+      (loader) => /(^|[\\/])babel-loader([\\/]|$)/.test(loader)
     )
     for (const loader of additionalBabelLoaders) {
       // @TODO support string options?
@@ -183,7 +183,7 @@ export default class NextEsmPlugin implements Plugin {
     }
 
     if (options.plugins) {
-      options.plugins = options.plugins.map(plugin => {
+      options.plugins = options.plugins.map((plugin) => {
         const name = Array.isArray(plugin) ? plugin[0] : plugin
         const opts = Object.assign(
           {},
@@ -284,7 +284,7 @@ export default class NextEsmPlugin implements Plugin {
     }
 
     let plugins = (compiler.options.plugins || []).filter(
-      c => !this.options.excludedPlugins.includes(c.constructor.name)
+      (c) => !this.options.excludedPlugins.includes(c.constructor.name)
     )
 
     // Add the additionalPlugins
@@ -322,7 +322,7 @@ export default class NextEsmPlugin implements Plugin {
       compilerEntries = { index: compilerEntries }
     }
 
-    Object.keys(compilerEntries).forEach(entry => {
+    Object.keys(compilerEntries).forEach((entry) => {
       const entryFiles = compilerEntries[entry]
       if (Array.isArray(entryFiles)) {
         new MultiEntryPlugin(compiler.context, entryFiles, entry).apply(
diff --git a/packages/next/build/webpack/plugins/pages-manifest-plugin.ts b/packages/next/build/webpack/plugins/pages-manifest-plugin.ts
index bed521bf19..8e3012da83 100644
--- a/packages/next/build/webpack/plugins/pages-manifest-plugin.ts
+++ b/packages/next/build/webpack/plugins/pages-manifest-plugin.ts
@@ -17,7 +17,7 @@ export default class PagesManifestPlugin implements Plugin {
   }
 
   apply(compiler: Compiler): void {
-    compiler.hooks.emit.tap('NextJsPagesManifest', compilation => {
+    compiler.hooks.emit.tap('NextJsPagesManifest', (compilation) => {
       const { chunks } = compilation
       const pages: { [page: string]: string } = {}
 
diff --git a/packages/next/build/webpack/plugins/profiling-plugin.ts b/packages/next/build/webpack/plugins/profiling-plugin.ts
index 3d30fd4cb0..b01bb48b59 100644
--- a/packages/next/build/webpack/plugins/profiling-plugin.ts
+++ b/packages/next/build/webpack/plugins/profiling-plugin.ts
@@ -40,13 +40,13 @@ export class ProfilingPlugin {
     const tracer = this.tracer
 
     // Compiler Hooks
-    Object.keys(compiler.hooks).forEach(hookName => {
+    Object.keys(compiler.hooks).forEach((hookName) => {
       compiler.hooks[hookName].intercept(
         makeInterceptorFor('Compiler', tracer)(hookName)
       )
     })
 
-    Object.keys(compiler.resolverFactory.hooks).forEach(hookName => {
+    Object.keys(compiler.resolverFactory.hooks).forEach((hookName) => {
       compiler.resolverFactory.hooks[hookName].intercept(
         makeInterceptorFor('Resolver', tracer)(hookName)
       )
@@ -106,8 +106,8 @@ const interceptTemplateInstancesFrom = (compilation: any, tracer: any) => {
       instance: webassembly,
       name: 'WebAssemblyModuleTemplate',
     },
-  ].forEach(templateObject => {
-    Object.keys(templateObject.instance.hooks).forEach(hookName => {
+  ].forEach((templateObject) => {
+    Object.keys(templateObject.instance.hooks).forEach((hookName) => {
       templateObject.instance.hooks[hookName].intercept(
         makeInterceptorFor(templateObject.name, tracer)(hookName)
       )
@@ -117,7 +117,7 @@ const interceptTemplateInstancesFrom = (compilation: any, tracer: any) => {
 
 const interceptAllHooksFor = (instance: any, tracer: any, logLabel: any) => {
   if (Reflect.has(instance, 'hooks')) {
-    Object.keys(instance.hooks).forEach(hookName => {
+    Object.keys(instance.hooks).forEach((hookName) => {
       instance.hooks[hookName].intercept(
         makeInterceptorFor(logLabel, tracer)(hookName)
       )
@@ -134,7 +134,7 @@ const interceptAllParserHooks = (moduleFactory: any, tracer: any) => {
     'webassembly/experimental',
   ]
 
-  moduleTypes.forEach(moduleType => {
+  moduleTypes.forEach((moduleType) => {
     moduleFactory.hooks.parser
       .for(moduleType)
       .tap('ProfilingPlugin', (parser: any, parserOpts: any) => {
diff --git a/packages/next/build/webpack/plugins/react-loadable-plugin.ts b/packages/next/build/webpack/plugins/react-loadable-plugin.ts
index 6988fc1ff8..116f3c934e 100644
--- a/packages/next/build/webpack/plugins/react-loadable-plugin.ts
+++ b/packages/next/build/webpack/plugins/react-loadable-plugin.ts
@@ -36,7 +36,7 @@ function buildManifest(
   let context = compiler.options.context
   let manifest: { [k: string]: any[] } = {}
 
-  compilation.chunkGroups.forEach(chunkGroup => {
+  compilation.chunkGroups.forEach((chunkGroup) => {
     if (chunkGroup.isInitial()) {
       return
     }
@@ -69,7 +69,7 @@ function buildManifest(
             // Avoid duplicate files
             if (
               manifest[request].some(
-                item => item.id === id && item.file === file
+                (item) => item.id === id && item.file === file
               )
             ) {
               continue
diff --git a/packages/next/build/webpack/plugins/serverless-plugin.ts b/packages/next/build/webpack/plugins/serverless-plugin.ts
index 01a1962dc8..72e0a5fa97 100644
--- a/packages/next/build/webpack/plugins/serverless-plugin.ts
+++ b/packages/next/build/webpack/plugins/serverless-plugin.ts
@@ -9,22 +9,25 @@ import { connectChunkAndModule } from 'webpack/lib/GraphHelpers'
 
 export class ServerlessPlugin {
   apply(compiler: Compiler) {
-    compiler.hooks.compilation.tap('ServerlessPlugin', compilation => {
-      compilation.hooks.optimizeChunksBasic.tap('ServerlessPlugin', chunks => {
-        chunks.forEach(chunk => {
-          // If chunk is not an entry point skip them
-          if (chunk.hasEntryModule()) {
-            const dynamicChunks = chunk.getAllAsyncChunks()
-            if (dynamicChunks.size !== 0) {
-              for (const dynamicChunk of dynamicChunks) {
-                for (const module of dynamicChunk.modulesIterable) {
-                  connectChunkAndModule(chunk, module)
+    compiler.hooks.compilation.tap('ServerlessPlugin', (compilation) => {
+      compilation.hooks.optimizeChunksBasic.tap(
+        'ServerlessPlugin',
+        (chunks) => {
+          chunks.forEach((chunk) => {
+            // If chunk is not an entry point skip them
+            if (chunk.hasEntryModule()) {
+              const dynamicChunks = chunk.getAllAsyncChunks()
+              if (dynamicChunks.size !== 0) {
+                for (const dynamicChunk of dynamicChunks) {
+                  for (const module of dynamicChunk.modulesIterable) {
+                    connectChunkAndModule(chunk, module)
+                  }
                 }
               }
             }
-          }
-        })
-      })
+          })
+        }
+      )
     })
   }
 }
diff --git a/packages/next/build/webpack/plugins/unlink-removed-pages-plugin.ts b/packages/next/build/webpack/plugins/unlink-removed-pages-plugin.ts
index e186acec60..283fd704ec 100644
--- a/packages/next/build/webpack/plugins/unlink-removed-pages-plugin.ts
+++ b/packages/next/build/webpack/plugins/unlink-removed-pages-plugin.ts
@@ -15,13 +15,13 @@ export class UnlinkRemovedPagesPlugin {
       'NextJsUnlinkRemovedPages',
       (compilation, callback) => {
         const removed = Object.keys(this.prevAssets).filter(
-          a => IS_BUNDLED_PAGE_REGEX.test(a) && !compilation.assets[a]
+          (a) => IS_BUNDLED_PAGE_REGEX.test(a) && !compilation.assets[a]
         )
 
         this.prevAssets = compilation.assets
 
         Promise.all(
-          removed.map(async f => {
+          removed.map(async (f) => {
             const path = join((compiler as any).outputPath, f)
             try {
               await promises.unlink(path)
diff --git a/packages/next/build/webpack/plugins/webpack-conformance-plugin/checks/duplicate-polyfills-conformance-check.ts b/packages/next/build/webpack/plugins/webpack-conformance-plugin/checks/duplicate-polyfills-conformance-check.ts
index 451720c1aa..1641873ca6 100644
--- a/packages/next/build/webpack/plugins/webpack-conformance-plugin/checks/duplicate-polyfills-conformance-check.ts
+++ b/packages/next/build/webpack/plugins/webpack-conformance-plugin/checks/duplicate-polyfills-conformance-check.ts
@@ -205,6 +205,6 @@ function doesScriptLoadBannedAPIfromPolyfillIO(
   const url = new URL(source)
   if (url.hostname === 'polyfill.io' && url.searchParams.has('features')) {
     const requestedAPIs = (url.searchParams.get('features') || '').split(',')
-    return blockedAPIs.find(api => requestedAPIs.includes(api))
+    return blockedAPIs.find((api) => requestedAPIs.includes(api))
   }
 }
diff --git a/packages/next/build/webpack/plugins/webpack-conformance-plugin/index.ts b/packages/next/build/webpack/plugins/webpack-conformance-plugin/index.ts
index e62ce3f2ae..e64afeda1a 100644
--- a/packages/next/build/webpack/plugins/webpack-conformance-plugin/index.ts
+++ b/packages/next/build/webpack/plugins/webpack-conformance-plugin/index.ts
@@ -38,7 +38,7 @@ export default class WebpackConformancePlugin {
   }
 
   private gatherResults(results: Array<IConformanceTestResult>): void {
-    results.forEach(result => {
+    results.forEach((result) => {
       if (result.result === IConformanceTestStatus.FAILED) {
         result.errors && this.errors.push(...result.errors)
         result.warnings && this.warnings.push(...result.warnings)
@@ -51,7 +51,7 @@ export default class WebpackConformancePlugin {
     callback: () => void
   ) => {
     const buildStartedResults: IConformanceTestResult[] = this.tests.map(
-      test => {
+      (test) => {
         if (test.buildStared && this.compiler) {
           return test.buildStared(this.compiler.options)
         }
@@ -70,7 +70,7 @@ export default class WebpackConformancePlugin {
     cb: () => void
   ): void => {
     const buildCompletedResults: IConformanceTestResult[] = this.tests.map(
-      test => {
+      (test) => {
         if (test.buildCompleted) {
           return test.buildCompleted(compilation.assets)
         }
@@ -90,10 +90,10 @@ export default class WebpackConformancePlugin {
     const JS_TYPES = ['auto', 'esm', 'dynamic']
     const collectedVisitors: Map<string, [NodeInspector?]> = new Map()
     // Collect all interested visitors from all tests.
-    this.tests.forEach(test => {
+    this.tests.forEach((test) => {
       if (test.getAstNode) {
         const getAstNodeCallbacks: IGetAstNodeResult[] = test.getAstNode()
-        getAstNodeCallbacks.forEach(result => {
+        getAstNodeCallbacks.forEach((result) => {
           if (!collectedVisitors.has(result.visitor)) {
             collectedVisitors.set(result.visitor, [])
           }
@@ -108,14 +108,14 @@ export default class WebpackConformancePlugin {
     for (const type of JS_TYPES) {
       factory.hooks.parser
         .for('javascript/' + type)
-        .tap(this.constructor.name, parser => {
+        .tap(this.constructor.name, (parser) => {
           parser.hooks.program.tap(this.constructor.name, (ast: any) => {
             const visitors: VisitorMap = {}
             const that = this
             for (const visitorKey of collectedVisitors.keys()) {
-              visitors[visitorKey] = function(path: NodePath) {
+              visitors[visitorKey] = function (path: NodePath) {
                 const callbacks = collectedVisitors.get(visitorKey) || []
-                callbacks.forEach(cb => {
+                callbacks.forEach((cb) => {
                   if (!cb) {
                     return
                   }
diff --git a/packages/next/build/webpack/plugins/wellknown-errors-plugin/index.ts b/packages/next/build/webpack/plugins/wellknown-errors-plugin/index.ts
index 48857d9970..6e25447340 100644
--- a/packages/next/build/webpack/plugins/wellknown-errors-plugin/index.ts
+++ b/packages/next/build/webpack/plugins/wellknown-errors-plugin/index.ts
@@ -3,10 +3,10 @@ import { getModuleBuildError } from './webpackModuleError'
 
 export class WellKnownErrorsPlugin {
   apply(compiler: Compiler) {
-    compiler.hooks.compilation.tap('WellKnownErrorsPlugin', compilation => {
+    compiler.hooks.compilation.tap('WellKnownErrorsPlugin', (compilation) => {
       compilation.hooks.seal.tap('WellKnownErrorsPlugin', () => {
         if (compilation.errors?.length) {
-          compilation.errors = compilation.errors.map(err => {
+          compilation.errors = compilation.errors.map((err) => {
             const moduleError = getModuleBuildError(compilation, err)
             return moduleError === false ? err : moduleError
           })
diff --git a/packages/next/cli/next-build.ts b/packages/next/cli/next-build.ts
index 2c00d691f4..21bf0bfd75 100755
--- a/packages/next/cli/next-build.ts
+++ b/packages/next/cli/next-build.ts
@@ -7,7 +7,7 @@ import { cliCommand } from '../bin/next'
 import build from '../build'
 import { printAndExit } from '../server/lib/utils'
 
-const nextBuild: cliCommand = argv => {
+const nextBuild: cliCommand = (argv) => {
   const args = arg(
     {
       // Types
@@ -43,7 +43,7 @@ const nextBuild: cliCommand = argv => {
 
   build(dir)
     .then(() => process.exit(0))
-    .catch(err => {
+    .catch((err) => {
       console.error('')
       console.error('> Build error occurred')
       printAndExit(err)
diff --git a/packages/next/cli/next-dev.ts b/packages/next/cli/next-dev.ts
index d615f7306a..e010277ff9 100755
--- a/packages/next/cli/next-dev.ts
+++ b/packages/next/cli/next-dev.ts
@@ -7,7 +7,7 @@ import { printAndExit } from '../server/lib/utils'
 import { startedDevelopmentServer } from '../build/output'
 import { cliCommand } from '../bin/next'
 
-const nextDev: cliCommand = argv => {
+const nextDev: cliCommand = (argv) => {
   const args = arg(
     {
       // Types
@@ -61,10 +61,10 @@ const nextDev: cliCommand = argv => {
     port,
     args['--hostname']
   )
-    .then(async app => {
+    .then(async (app) => {
       await app.prepare()
     })
-    .catch(err => {
+    .catch((err) => {
       if (err.code === 'EADDRINUSE') {
         let errorMessage = `Port ${port} is already in use.`
         const pkgAppPath = require('next/dist/compiled/find-up').sync(
@@ -76,7 +76,7 @@ const nextDev: cliCommand = argv => {
         const appPackage = require(pkgAppPath)
         if (appPackage.scripts) {
           const nextScript = Object.entries(appPackage.scripts).find(
-            scriptLine => scriptLine[1] === 'next'
+            (scriptLine) => scriptLine[1] === 'next'
           )
           if (nextScript) {
             errorMessage += `\nUse \`npm run ${nextScript[0]} -- -p <some other port>\`.`
diff --git a/packages/next/cli/next-export.ts b/packages/next/cli/next-export.ts
index 061be66ac7..29e8085d0a 100755
--- a/packages/next/cli/next-export.ts
+++ b/packages/next/cli/next-export.ts
@@ -6,7 +6,7 @@ import exportApp from '../export'
 import { printAndExit } from '../server/lib/utils'
 import { cliCommand } from '../bin/next'
 
-const nextExport: cliCommand = argv => {
+const nextExport: cliCommand = (argv) => {
   const args = arg(
     {
       // Types
@@ -60,7 +60,7 @@ const nextExport: cliCommand = argv => {
     .then(() => {
       printAndExit('Export successful', 0)
     })
-    .catch(err => {
+    .catch((err) => {
       printAndExit(err)
     })
 }
diff --git a/packages/next/cli/next-start.ts b/packages/next/cli/next-start.ts
index 3d56a8c3dd..90d89d9fcd 100755
--- a/packages/next/cli/next-start.ts
+++ b/packages/next/cli/next-start.ts
@@ -6,7 +6,7 @@ import startServer from '../server/lib/start-server'
 import { cliCommand } from '../bin/next'
 import * as Log from '../build/output/log'
 
-const nextStart: cliCommand = argv => {
+const nextStart: cliCommand = (argv) => {
   const args = arg(
     {
       // Types
@@ -46,14 +46,14 @@ const nextStart: cliCommand = argv => {
   const dir = resolve(args._[0] || '.')
   const port = args['--port'] || 3000
   startServer({ dir }, port, args['--hostname'])
-    .then(async app => {
+    .then(async (app) => {
       // tslint:disable-next-line
       Log.ready(
         `started server on http://${args['--hostname'] || 'localhost'}:${port}`
       )
       await app.prepare()
     })
-    .catch(err => {
+    .catch((err) => {
       // tslint:disable-next-line
       console.error(err)
       process.exit(1)
diff --git a/packages/next/cli/next-telemetry.ts b/packages/next/cli/next-telemetry.ts
index 2fbf010eb2..58b97ac8ba 100755
--- a/packages/next/cli/next-telemetry.ts
+++ b/packages/next/cli/next-telemetry.ts
@@ -5,7 +5,7 @@ import arg from 'next/dist/compiled/arg/index.js'
 import { cliCommand } from '../bin/next'
 import { Telemetry } from '../telemetry/storage'
 
-const nextTelemetry: cliCommand = argv => {
+const nextTelemetry: cliCommand = (argv) => {
   const args = arg(
     {
       // Types
diff --git a/packages/next/client/dev/amp-dev.js b/packages/next/client/dev/amp-dev.js
index 5ad1fbf054..e1fc9d389f 100644
--- a/packages/next/client/dev/amp-dev.js
+++ b/packages/next/client/dev/amp-dev.js
@@ -41,7 +41,7 @@ async function tryApplyUpdates() {
     const res = await fetch(`${hotUpdatePath}${curHash}.hot-update.json`)
     const data = await res.json()
     const curPage = page === '/' ? 'index' : page
-    const pageUpdated = Object.keys(data.c).some(mod => {
+    const pageUpdated = Object.keys(data.c).some((mod) => {
       return (
         mod.indexOf(
           `pages${curPage.substr(0, 1) === '/' ? curPage : `/${curPage}`}`
@@ -67,7 +67,7 @@ async function tryApplyUpdates() {
 
 getEventSourceWrapper({
   path: `${assetPrefix}/_next/webpack-hmr`,
-}).addMessageListener(event => {
+}).addMessageListener((event) => {
   if (event.data === '\uD83D\uDC93') {
     return
   }
diff --git a/packages/next/client/dev/dev-build-watcher.js b/packages/next/client/dev/dev-build-watcher.js
index 570e3805be..aa3661b2c0 100644
--- a/packages/next/client/dev/dev-build-watcher.js
+++ b/packages/next/client/dev/dev-build-watcher.js
@@ -40,7 +40,7 @@ export default function initializeBuildWatcher() {
 
   // Handle events
   const evtSource = getEventSourceWrapper({ path: '/_next/webpack-hmr' })
-  evtSource.addMessageListener(event => {
+  evtSource.addMessageListener((event) => {
     // This is the heartbeat event
     if (event.data === '\uD83D\uDC93') {
       return
diff --git a/packages/next/client/dev/error-overlay/eventsource.js b/packages/next/client/dev/error-overlay/eventsource.js
index ce83fb9eb3..dd87e84a64 100644
--- a/packages/next/client/dev/error-overlay/eventsource.js
+++ b/packages/next/client/dev/error-overlay/eventsource.js
@@ -10,7 +10,7 @@ function EventSourceWrapper(options) {
   }
 
   init()
-  var timer = setInterval(function() {
+  var timer = setInterval(function () {
     if (new Date() - lastActivity > options.timeout) {
       handleDisconnect()
     }
@@ -34,7 +34,7 @@ function EventSourceWrapper(options) {
       listeners[i](event)
     }
     if (event.data.indexOf('action') !== -1) {
-      eventCallbacks.forEach(cb => cb(event))
+      eventCallbacks.forEach((cb) => cb(event))
     }
   }
 
@@ -49,7 +49,7 @@ function EventSourceWrapper(options) {
       clearInterval(timer)
       source.close()
     },
-    addMessageListener: function(fn) {
+    addMessageListener: function (fn) {
       listeners.push(fn)
     },
   }
@@ -58,7 +58,7 @@ function EventSourceWrapper(options) {
 export function getEventSourceWrapper(options) {
   if (!options.ondemand) {
     return {
-      addMessageListener: cb => {
+      addMessageListener: (cb) => {
         eventCallbacks.push(cb)
       },
     }
diff --git a/packages/next/client/dev/error-overlay/format-webpack-messages.js b/packages/next/client/dev/error-overlay/format-webpack-messages.js
index c61845352f..34d5e36fe0 100644
--- a/packages/next/client/dev/error-overlay/format-webpack-messages.js
+++ b/packages/next/client/dev/error-overlay/format-webpack-messages.js
@@ -36,11 +36,11 @@ function formatMessage(message) {
 
   // Strip Webpack-added headers off errors/warnings
   // https://github.com/webpack/webpack/blob/master/lib/ModuleError.js
-  lines = lines.filter(line => !/Module [A-z ]+\(from/.test(line))
+  lines = lines.filter((line) => !/Module [A-z ]+\(from/.test(line))
 
   // Transform parsing error into syntax error
   // TODO: move this to our ESLint formatter?
-  lines = lines.map(line => {
+  lines = lines.map((line) => {
     const parsingError = /Line (\d+):(?:(\d+):)?\s*Parsing error: (.+)$/.exec(
       line
     )
@@ -124,10 +124,10 @@ function formatMessage(message) {
 }
 
 function formatWebpackMessages(json) {
-  const formattedErrors = json.errors.map(function(message) {
+  const formattedErrors = json.errors.map(function (message) {
     return formatMessage(message, true)
   })
-  const formattedWarnings = json.warnings.map(function(message) {
+  const formattedWarnings = json.warnings.map(function (message) {
     return formatMessage(message, false)
   })
   const result = { errors: formattedErrors, warnings: formattedWarnings }
diff --git a/packages/next/client/dev/error-overlay/hot-dev-client.js b/packages/next/client/dev/error-overlay/hot-dev-client.js
index 8dfddd95f3..ca1a32e972 100644
--- a/packages/next/client/dev/error-overlay/hot-dev-client.js
+++ b/packages/next/client/dev/error-overlay/hot-dev-client.js
@@ -45,7 +45,7 @@ let customHmrEventHandler
 export default function connect(options) {
   DevOverlay.register()
 
-  getEventSourceWrapper(options).addMessageListener(event => {
+  getEventSourceWrapper(options).addMessageListener((event) => {
     // This is the heartbeat event
     if (event.data === '\uD83D\uDC93') {
       return
@@ -307,10 +307,10 @@ function tryApplyUpdates(onHotUpdateSuccess) {
 
   // https://webpack.js.org/api/hot-module-replacement/#check
   module.hot.check(/* autoApply */ true).then(
-    updatedModules => {
+    (updatedModules) => {
       handleApplyUpdates(null, updatedModules)
     },
-    err => {
+    (err) => {
       handleApplyUpdates(err, null)
     }
   )
diff --git a/packages/next/client/dev/event-source-polyfill.js b/packages/next/client/dev/event-source-polyfill.js
index 6173a40049..643f8aaaf1 100644
--- a/packages/next/client/dev/event-source-polyfill.js
+++ b/packages/next/client/dev/event-source-polyfill.js
@@ -11,9 +11,9 @@ var TextEncoder = window.TextEncoder
 var AbortController = window.AbortController
 
 if (AbortController == undefined) {
-  AbortController = function() {
+  AbortController = function () {
     this.signal = null
-    this.abort = function() {}
+    this.abort = function () {}
   }
 }
 
@@ -22,7 +22,7 @@ function TextDecoderPolyfill() {
   this.codePoint = 0
 }
 
-TextDecoderPolyfill.prototype.decode = function(octets) {
+TextDecoderPolyfill.prototype.decode = function (octets) {
   function valid(codePoint, shift, octetsCount) {
     if (octetsCount === 1) {
       return codePoint >= 0x0080 >> shift && codePoint << shift <= 0x07ff
@@ -116,7 +116,7 @@ TextDecoderPolyfill.prototype.decode = function(octets) {
 }
 
 // Firefox < 38 throws an error with stream option
-var supportsStreamOption = function() {
+var supportsStreamOption = function () {
   try {
     return (
       new TextDecoder().decode(new TextEncoder().encode('test'), {
@@ -138,7 +138,7 @@ if (
   TextDecoder = TextDecoderPolyfill
 }
 
-var k = function() {}
+var k = function () {}
 
 function XHRWrapper(xhr) {
   this.withCredentials = false
@@ -155,7 +155,7 @@ function XHRWrapper(xhr) {
   this._abort = k
 }
 
-XHRWrapper.prototype.open = function(method, url) {
+XHRWrapper.prototype.open = function (method, url) {
   this._abort(true)
 
   var that = this
@@ -163,7 +163,7 @@ XHRWrapper.prototype.open = function(method, url) {
   var state = 1
   var timeout = 0
 
-  this._abort = function(silent) {
+  this._abort = function (silent) {
     if (that._sendTimeout !== 0) {
       clearTimeout(that._sendTimeout)
       that._sendTimeout = 0
@@ -190,7 +190,7 @@ XHRWrapper.prototype.open = function(method, url) {
     state = 0
   }
 
-  var onStart = function() {
+  var onStart = function () {
     if (state === 1) {
       // state = 2;
       var status = 0
@@ -227,7 +227,7 @@ XHRWrapper.prototype.open = function(method, url) {
       }
     }
   }
-  var onProgress = function() {
+  var onProgress = function () {
     onStart()
     if (state === 2 || state === 3) {
       state = 3
@@ -242,7 +242,7 @@ XHRWrapper.prototype.open = function(method, url) {
       that.onprogress()
     }
   }
-  var onFinish = function() {
+  var onFinish = function () {
     // Firefox 52 fires "readystatechange" (xhr.readyState === 4) without final "readystatechange" (xhr.readyState === 3)
     // IE 8 fires "onload" without "onprogress"
     onProgress()
@@ -256,7 +256,7 @@ XHRWrapper.prototype.open = function(method, url) {
       that.onreadystatechange()
     }
   }
-  var onReadyStateChange = function() {
+  var onReadyStateChange = function () {
     if (xhr != undefined) {
       // Opera 12
       if (xhr.readyState === 4) {
@@ -268,8 +268,8 @@ XHRWrapper.prototype.open = function(method, url) {
       }
     }
   }
-  var onTimeout = function() {
-    timeout = setTimeout(function() {
+  var onTimeout = function () {
+    timeout = setTimeout(function () {
       onTimeout()
     }, 500)
     if (xhr.readyState === 3) {
@@ -311,29 +311,29 @@ XHRWrapper.prototype.open = function(method, url) {
   if ('readyState' in xhr) {
     // workaround for Opera 12 issue with "progress" events
     // #91
-    timeout = setTimeout(function() {
+    timeout = setTimeout(function () {
       onTimeout()
     }, 0)
   }
 }
-XHRWrapper.prototype.abort = function() {
+XHRWrapper.prototype.abort = function () {
   this._abort(false)
 }
-XHRWrapper.prototype.getResponseHeader = function(name) {
+XHRWrapper.prototype.getResponseHeader = function (name) {
   return this._contentType
 }
-XHRWrapper.prototype.setRequestHeader = function(name, value) {
+XHRWrapper.prototype.setRequestHeader = function (name, value) {
   var xhr = this._xhr
   if ('setRequestHeader' in xhr) {
     xhr.setRequestHeader(name, value)
   }
 }
-XHRWrapper.prototype.getAllResponseHeaders = function() {
+XHRWrapper.prototype.getAllResponseHeaders = function () {
   return this._xhr.getAllResponseHeaders != undefined
     ? this._xhr.getAllResponseHeaders()
     : ''
 }
-XHRWrapper.prototype.send = function() {
+XHRWrapper.prototype.send = function () {
   // loading indicator in Safari < ? (6), Chrome < 14, Firefox
   if (
     !('ontimeout' in XMLHttpRequest.prototype) &&
@@ -342,7 +342,7 @@ XHRWrapper.prototype.send = function() {
     document.readyState !== 'complete'
   ) {
     var that = this
-    that._sendTimeout = setTimeout(function() {
+    that._sendTimeout = setTimeout(function () {
       that._sendTimeout = 0
       that.send()
     }, 4)
@@ -363,7 +363,7 @@ XHRWrapper.prototype.send = function() {
 }
 
 function toLowerCase(name) {
-  return name.replace(/[A-Z]/g, function(c) {
+  return name.replace(/[A-Z]/g, function (c) {
     return String.fromCharCode(c.charCodeAt(0) + 0x20)
   })
 }
@@ -381,13 +381,13 @@ function HeadersPolyfill(all) {
   }
   this._map = map
 }
-HeadersPolyfill.prototype.get = function(name) {
+HeadersPolyfill.prototype.get = function (name) {
   return this._map[toLowerCase(name)]
 }
 
 function XHRTransport() {}
 
-XHRTransport.prototype.open = function(
+XHRTransport.prototype.open = function (
   xhr,
   onStartCallback,
   onProgressCallback,
@@ -398,13 +398,13 @@ XHRTransport.prototype.open = function(
 ) {
   xhr.open('GET', url)
   var offset = 0
-  xhr.onprogress = function() {
+  xhr.onprogress = function () {
     var responseText = xhr.responseText
     var chunk = responseText.slice(offset)
     offset += chunk.length
     onProgressCallback(chunk)
   }
-  xhr.onreadystatechange = function() {
+  xhr.onreadystatechange = function () {
     if (xhr.readyState === 2) {
       var status = xhr.status
       var statusText = xhr.statusText
@@ -415,7 +415,7 @@ XHRTransport.prototype.open = function(
         statusText,
         contentType,
         new HeadersPolyfill(headers),
-        function() {
+        function () {
           xhr.abort()
         }
       )
@@ -436,13 +436,13 @@ XHRTransport.prototype.open = function(
 function HeadersWrapper(headers) {
   this._headers = headers
 }
-HeadersWrapper.prototype.get = function(name) {
+HeadersWrapper.prototype.get = function (name) {
   return this._headers.get(name)
 }
 
 function FetchTransport() {}
 
-FetchTransport.prototype.open = function(
+FetchTransport.prototype.open = function (
   xhr,
   onStartCallback,
   onProgressCallback,
@@ -460,23 +460,23 @@ FetchTransport.prototype.open = function(
     signal: signal,
     cache: 'no-store',
   })
-    .then(function(response) {
+    .then(function (response) {
       var reader = response.body.getReader()
       onStartCallback(
         response.status,
         response.statusText,
         response.headers.get('Content-Type'),
         new HeadersWrapper(response.headers),
-        function() {
+        function () {
           controller.abort()
           reader.cancel()
         }
       )
-      return new Promise(function(resolve, reject) {
-        var readNextChunk = function() {
+      return new Promise(function (resolve, reject) {
+        var readNextChunk = function () {
           reader
             .read()
-            .then(function(result) {
+            .then(function (result) {
               if (result.done) {
                 // Note: bytes in textDecoder are ignored
                 resolve(undefined)
@@ -486,7 +486,7 @@ FetchTransport.prototype.open = function(
                 readNextChunk()
               }
             })
-            ['catch'](function(error) {
+            ['catch'](function (error) {
               reject(error)
             })
         }
@@ -494,11 +494,11 @@ FetchTransport.prototype.open = function(
       })
     })
     .then(
-      function(result) {
+      function (result) {
         onFinishCallback()
         return result
       },
-      function(error) {
+      function (error) {
         onFinishCallback()
         return Promise.reject(error)
       }
@@ -510,12 +510,12 @@ function EventTarget() {
 }
 
 function throwError(e) {
-  setTimeout(function() {
+  setTimeout(function () {
     throw e
   }, 0)
 }
 
-EventTarget.prototype.dispatchEvent = function(event) {
+EventTarget.prototype.dispatchEvent = function (event) {
   event.target = this
   var typeListeners = this._listeners[event.type]
   if (typeListeners != undefined) {
@@ -534,7 +534,7 @@ EventTarget.prototype.dispatchEvent = function(event) {
     }
   }
 }
-EventTarget.prototype.addEventListener = function(type, listener) {
+EventTarget.prototype.addEventListener = function (type, listener) {
   type = String(type)
   var listeners = this._listeners
   var typeListeners = listeners[type]
@@ -552,7 +552,7 @@ EventTarget.prototype.addEventListener = function(type, listener) {
     typeListeners.push(listener)
   }
 }
-EventTarget.prototype.removeEventListener = function(type, listener) {
+EventTarget.prototype.removeEventListener = function (type, listener) {
   type = String(type)
   var listeners = this._listeners
   var typeListeners = listeners[type]
@@ -609,18 +609,18 @@ var contentTypeRegExp = /^text\/event\-stream;?(\s*charset\=utf\-8)?$/i
 var MINIMUM_DURATION = 1000
 var MAXIMUM_DURATION = 18000000
 
-var parseDuration = function(value, def) {
+var parseDuration = function (value, def) {
   var n = parseInt(value, 10)
   if (n !== n) {
     n = def
   }
   return clampDuration(n)
 }
-var clampDuration = function(n) {
+var clampDuration = function (n) {
   return Math.min(Math.max(n, MINIMUM_DURATION), MAXIMUM_DURATION)
 }
 
-var fire = function(that, f, event) {
+var fire = function (that, f, event) {
   try {
     if (typeof f === 'function') {
       f.call(that, event)
@@ -688,7 +688,7 @@ function start(es, url, options) {
   var fieldStart = 0
   var valueStart = 0
 
-  var onStart = function(status, statusText, contentType, headers, cancel) {
+  var onStart = function (status, statusText, contentType, headers, cancel) {
     if (currentState === CONNECTING) {
       cancelFunction = cancel
       if (
@@ -740,7 +740,7 @@ function start(es, url, options) {
     }
   }
 
-  var onProgress = function(textChunk) {
+  var onProgress = function (textChunk) {
     if (currentState === OPEN) {
       var n = -1
       for (var i = 0; i < textChunk.length; i += 1) {
@@ -790,7 +790,7 @@ function start(es, url, options) {
                 heartbeatTimeout = parseDuration(value, heartbeatTimeout)
                 if (timeout !== 0) {
                   clearTimeout(timeout)
-                  timeout = setTimeout(function() {
+                  timeout = setTimeout(function () {
                     onTimeout()
                   }, heartbeatTimeout)
                 }
@@ -837,14 +837,14 @@ function start(es, url, options) {
     }
   }
 
-  var onFinish = function() {
+  var onFinish = function () {
     if (currentState === OPEN || currentState === CONNECTING) {
       currentState = WAITING
       if (timeout !== 0) {
         clearTimeout(timeout)
         timeout = 0
       }
-      timeout = setTimeout(function() {
+      timeout = setTimeout(function () {
         onTimeout()
       }, retry)
       retry = clampDuration(Math.min(initialRetry * 16, retry * 2))
@@ -856,7 +856,7 @@ function start(es, url, options) {
     }
   }
 
-  var close = function() {
+  var close = function () {
     currentState = CLOSED
     if (cancelFunction != undefined) {
       cancelFunction()
@@ -869,7 +869,7 @@ function start(es, url, options) {
     es.readyState = CLOSED
   }
 
-  var onTimeout = function() {
+  var onTimeout = function () {
     timeout = 0
 
     if (currentState !== WAITING) {
@@ -885,7 +885,7 @@ function start(es, url, options) {
         cancelFunction = undefined
       } else {
         wasActivity = false
-        timeout = setTimeout(function() {
+        timeout = setTimeout(function () {
           onTimeout()
         }, heartbeatTimeout)
       }
@@ -893,7 +893,7 @@ function start(es, url, options) {
     }
 
     wasActivity = false
-    timeout = setTimeout(function() {
+    timeout = setTimeout(function () {
       onTimeout()
     }, heartbeatTimeout)
 
@@ -954,7 +954,7 @@ EventSourcePolyfill.prototype = Object.create(EventTarget.prototype)
 EventSourcePolyfill.prototype.CONNECTING = CONNECTING
 EventSourcePolyfill.prototype.OPEN = OPEN
 EventSourcePolyfill.prototype.CLOSED = CLOSED
-EventSourcePolyfill.prototype.close = function() {
+EventSourcePolyfill.prototype.close = function () {
   this._close()
 }
 
diff --git a/packages/next/client/dev/fouc.js b/packages/next/client/dev/fouc.js
index c67b799c99..ec14e42999 100644
--- a/packages/next/client/dev/fouc.js
+++ b/packages/next/client/dev/fouc.js
@@ -2,7 +2,7 @@ export function displayContent(callback) {
   // This is the fallback helper that removes Next.js' no-FOUC styles when
   // CSS mode is enabled. This only really activates if you haven't created
   // _any_ styles in your application yet.
-  ;(window.requestAnimationFrame || setTimeout)(function() {
+  ;(window.requestAnimationFrame || setTimeout)(function () {
     for (
       var x = document.querySelectorAll('[data-next-hide-fouc]'), i = x.length;
       i--;
diff --git a/packages/next/client/dev/on-demand-entries-client.js b/packages/next/client/dev/on-demand-entries-client.js
index a8e2436c26..3f11f6c87d 100644
--- a/packages/next/client/dev/on-demand-entries-client.js
+++ b/packages/next/client/dev/on-demand-entries-client.js
@@ -13,7 +13,7 @@ export default async ({ assetPrefix }) => {
 
   // prevent HMR connection from being closed when running tests
   if (!process.env.__NEXT_TEST_MODE) {
-    document.addEventListener('visibilitychange', event => {
+    document.addEventListener('visibilitychange', (event) => {
       const state = document.visibilityState
       if (state === 'visible') {
         setupPing(assetPrefix, () => Router.pathname, true)
diff --git a/packages/next/client/dev/on-demand-entries-utils.js b/packages/next/client/dev/on-demand-entries-utils.js
index 22f6f037df..e17ac44872 100644
--- a/packages/next/client/dev/on-demand-entries-utils.js
+++ b/packages/next/client/dev/on-demand-entries-utils.js
@@ -23,7 +23,7 @@ export function setupPing(assetPrefix, pathnameFn, retry) {
   const url = `${assetPrefix}/_next/webpack-hmr?page=${currentPage}`
   evtSource = getEventSourceWrapper({ path: url, timeout: 5000, ondemand: 1 })
 
-  evtSource.addMessageListener(event => {
+  evtSource.addMessageListener((event) => {
     if (event.data.indexOf('{') === -1) return
     try {
       const payload = JSON.parse(event.data)
@@ -32,7 +32,7 @@ export function setupPing(assetPrefix, pathnameFn, retry) {
         // So, we need to make sure it exists before reloading.
         fetch(location.href, {
           credentials: 'same-origin',
-        }).then(pageRes => {
+        }).then((pageRes) => {
           if (pageRes.status === 200) {
             location.reload()
           }
diff --git a/packages/next/client/dev/webpack-hot-middleware-client.js b/packages/next/client/dev/webpack-hot-middleware-client.js
index a938fdcbc7..42e0728960 100644
--- a/packages/next/client/dev/webpack-hot-middleware-client.js
+++ b/packages/next/client/dev/webpack-hot-middleware-client.js
@@ -7,7 +7,7 @@ export default ({ assetPrefix }) => {
 
   const devClient = connect(options)
 
-  devClient.subscribeToHmrEvent(obj => {
+  devClient.subscribeToHmrEvent((obj) => {
     if (obj.action === 'reloadPage') {
       return window.location.reload()
     }
diff --git a/packages/next/client/head-manager.js b/packages/next/client/head-manager.js
index 08b5c45a52..3a4fd79100 100644
--- a/packages/next/client/head-manager.js
+++ b/packages/next/client/head-manager.js
@@ -51,7 +51,7 @@ function updateElements(type, components) {
       oldTags.push(j)
     }
   }
-  const newTags = components.map(reactElementToDOM).filter(newTag => {
+  const newTags = components.map(reactElementToDOM).filter((newTag) => {
     for (let k = 0, len = oldTags.length; k < len; k++) {
       const oldTag = oldTags[k]
       if (oldTag.isEqualNode(newTag)) {
@@ -62,22 +62,22 @@ function updateElements(type, components) {
     return true
   })
 
-  oldTags.forEach(t => t.parentNode.removeChild(t))
-  newTags.forEach(t => headEl.insertBefore(t, headCountEl))
+  oldTags.forEach((t) => t.parentNode.removeChild(t))
+  newTags.forEach((t) => headEl.insertBefore(t, headCountEl))
   headCountEl.content = (headCount - oldTags.length + newTags.length).toString()
 }
 
 export default function initHeadManager() {
   let updatePromise = null
 
-  return head => {
+  return (head) => {
     const promise = (updatePromise = Promise.resolve().then(() => {
       if (promise !== updatePromise) return
 
       updatePromise = null
       const tags = {}
 
-      head.forEach(h => {
+      head.forEach((h) => {
         const components = tags[h.type] || []
         components.push(h)
         tags[h.type] = components
@@ -90,7 +90,7 @@ export default function initHeadManager() {
         title = typeof children === 'string' ? children : children.join('')
       }
       if (title !== document.title) document.title = title
-      ;['meta', 'base', 'link', 'style', 'script'].forEach(type => {
+      ;['meta', 'base', 'link', 'style', 'script'].forEach((type) => {
         updateElements(type, tags[type] || [])
       })
     }))
diff --git a/packages/next/client/index.js b/packages/next/client/index.js
index f6758d5180..68620f68c7 100644
--- a/packages/next/client/index.js
+++ b/packages/next/client/index.js
@@ -79,10 +79,10 @@ class Container extends React.Component {
     if (process.env.__NEXT_PLUGINS) {
       // eslint-disable-next-line
       import('next-plugin-loader?middleware=unstable-post-hydration!')
-        .then(mod => {
+        .then((mod) => {
           return mod.default()
         })
-        .catch(err => {
+        .catch((err) => {
           console.error('Error calling post-hydration for plugins', err)
         })
     }
@@ -179,8 +179,9 @@ export default async ({ webpackHMR: passedWebpackHMR } = {}) => {
       entries,
     }) => {
       // Combines timestamp with random number for unique ID
-      const uniqueID = `${Date.now()}-${Math.floor(Math.random() * (9e12 - 1)) +
-        1e12}`
+      const uniqueID = `${Date.now()}-${
+        Math.floor(Math.random() * (9e12 - 1)) + 1e12
+      }`
       let perfStartEntry
 
       if (entries && entries.length) {
@@ -273,10 +274,10 @@ export default async ({ webpackHMR: passedWebpackHMR } = {}) => {
   if (process.env.__NEXT_PLUGINS) {
     // eslint-disable-next-line
     import('next-plugin-loader?middleware=on-init-client!')
-      .then(mod => {
+      .then((mod) => {
         return mod.default({ router })
       })
-      .catch(err => {
+      .catch((err) => {
         console.error('Error calling client-init for plugins', err)
       })
   }
@@ -337,10 +338,10 @@ export function renderError(props) {
   if (process.env.__NEXT_PLUGINS) {
     // eslint-disable-next-line
     import('next-plugin-loader?middleware=on-error-client!')
-      .then(mod => {
+      .then((mod) => {
         return mod.default({ err })
       })
-      .catch(err => {
+      .catch((err) => {
         console.error('error calling on-error-client for plugins', err)
       })
   }
@@ -360,7 +361,7 @@ export function renderError(props) {
     }
     return Promise.resolve(
       props.props ? props.props : loadGetInitialProps(App, appCtx)
-    ).then(initProps =>
+    ).then((initProps) =>
       doRender({
         ...props,
         err,
@@ -445,7 +446,7 @@ function markRenderComplete() {
       .forEach(onPerfEntry)
   }
   clearMarks()
-  ;['Next.js-route-change-to-render', 'Next.js-render'].forEach(measure =>
+  ;['Next.js-route-change-to-render', 'Next.js-render'].forEach((measure) =>
     performance.clearMeasures(measure)
   )
 }
@@ -456,14 +457,14 @@ function clearMarks() {
     'afterHydrate',
     'afterRender',
     'routeChange',
-  ].forEach(mark => performance.clearMarks(mark))
+  ].forEach((mark) => performance.clearMarks(mark))
 }
 
 function AppContainer({ children }) {
   return (
     <Container
-      fn={error =>
-        renderError({ App, err: error }).catch(err =>
+      fn={(error) =>
+        renderError({ App, err: error }).catch((err) =>
           console.error('Error rendering page: ', err)
         )
       }
@@ -477,7 +478,7 @@ function AppContainer({ children }) {
   )
 }
 
-const wrapApp = App => props => {
+const wrapApp = (App) => (props) => {
   const appProps = { ...props, Component, err, router }
   return (
     <AppContainer>
diff --git a/packages/next/client/link.tsx b/packages/next/client/link.tsx
index 1d48341375..ef1374d4bc 100644
--- a/packages/next/client/link.tsx
+++ b/packages/next/client/link.tsx
@@ -72,8 +72,8 @@ function getObserver(): IntersectionObserver | undefined {
   }
 
   return (observer = new IntersectionObserver(
-    entries => {
-      entries.forEach(entry => {
+    (entries) => {
+      entries.forEach((entry) => {
         if (!listeners.has(entry.target)) {
           return
         }
@@ -220,7 +220,7 @@ class Link extends Component<LinkProps> {
     // loading with priority which can reject but we don't
     // want to force navigation since this is only a prefetch
     Router.prefetch(paths[/* href */ 0], paths[/* asPath */ 1], options).catch(
-      err => {
+      (err) => {
         if (process.env.NODE_ENV !== 'production') {
           // rethrow to show invalid URL errors
           throw err
diff --git a/packages/next/client/next-dev.js b/packages/next/client/next-dev.js
index c9282b62ee..c32f09e41b 100644
--- a/packages/next/client/next-dev.js
+++ b/packages/next/client/next-dev.js
@@ -66,6 +66,6 @@ initNext({ webpackHMR })
       }
     })
   })
-  .catch(err => {
+  .catch((err) => {
     console.error('Error was not caught', err)
   })
diff --git a/packages/next/client/next.js b/packages/next/client/next.js
index 99c698d9bb..9a616eec4f 100644
--- a/packages/next/client/next.js
+++ b/packages/next/client/next.js
@@ -2,6 +2,6 @@ import initNext, * as next from './'
 
 window.next = next
 
-initNext().catch(err => {
+initNext().catch((err) => {
   console.error(`${err.message}\n${err.stack}`)
 })
diff --git a/packages/next/client/page-loader.js b/packages/next/client/page-loader.js
index 4551667f53..67cc68680c 100644
--- a/packages/next/client/page-loader.js
+++ b/packages/next/client/page-loader.js
@@ -58,7 +58,7 @@ export default class PageLoader {
     this.pageRegisterEvents = mitt()
     this.loadingRoutes = {}
     if (process.env.__NEXT_GRANULAR_CHUNKS) {
-      this.promisedBuildManifest = new Promise(resolve => {
+      this.promisedBuildManifest = new Promise((resolve) => {
         if (window.__BUILD_MANIFEST) {
           resolve(window.__BUILD_MANIFEST)
         } else {
@@ -69,7 +69,7 @@ export default class PageLoader {
       })
     }
     /** @type {Promise<Set<string>>} */
-    this.promisedSsgManifest = new Promise(resolve => {
+    this.promisedSsgManifest = new Promise((resolve) => {
       if (window.__SSG_MANIFEST) {
         resolve(window.__SSG_MANIFEST)
       } else {
@@ -83,10 +83,10 @@ export default class PageLoader {
   // Returns a promise for the dependencies for a particular route
   getDependencies(route) {
     return this.promisedBuildManifest.then(
-      man =>
+      (man) =>
         (man[route] &&
           man[route].map(
-            url => `${this.assetPrefix}/_next/${encodeURI(url)}`
+            (url) => `${this.assetPrefix}/_next/${encodeURI(url)}`
           )) ||
         []
     )
@@ -123,7 +123,7 @@ export default class PageLoader {
 
       interpolatedRoute = route
       if (
-        !Object.keys(dynamicGroups).every(param => {
+        !Object.keys(dynamicGroups).every((param) => {
           let value = dynamicMatches[param]
           const repeat = dynamicGroups[param].repeat
 
@@ -216,8 +216,8 @@ export default class PageLoader {
       if (!this.loadingRoutes[route]) {
         this.loadingRoutes[route] = true
         if (process.env.__NEXT_GRANULAR_CHUNKS) {
-          this.getDependencies(route).then(deps => {
-            deps.forEach(d => {
+          this.getDependencies(route).then((deps) => {
+            deps.forEach((d) => {
               if (
                 /\.js$/.test(d) &&
                 !document.querySelector(`script[src^="${d}"]`)
@@ -293,7 +293,7 @@ export default class PageLoader {
           `Waiting for webpack to become "idle" to initialize the page: "${route}"`
         )
 
-        const check = status => {
+        const check = (status) => {
           if (status === 'idle') {
             module.hot.removeStatusHandler(check)
             register()
@@ -350,8 +350,8 @@ export default class PageLoader {
             ),
             process.env.__NEXT_GRANULAR_CHUNKS &&
               !isDependency &&
-              this.getDependencies(route).then(urls =>
-                Promise.all(urls.map(url => this.prefetch(url, true)))
+              this.getDependencies(route).then((urls) =>
+                Promise.all(urls.map((url) => this.prefetch(url, true)))
               ),
           ]
     ).then(
diff --git a/packages/next/client/performance-relayer.js b/packages/next/client/performance-relayer.js
index 8e1549e4fd..54907031f2 100644
--- a/packages/next/client/performance-relayer.js
+++ b/packages/next/client/performance-relayer.js
@@ -1,6 +1,6 @@
 import { getCLS, getFID, getFCP, getLCP, getTTFB } from 'web-vitals'
 
-export default onPerfEntry => {
+export default (onPerfEntry) => {
   getCLS(onPerfEntry)
   getFID(onPerfEntry)
   getFCP(onPerfEntry)
diff --git a/packages/next/client/router.ts b/packages/next/client/router.ts
index 80496e411c..1aab746062 100644
--- a/packages/next/client/router.ts
+++ b/packages/next/client/router.ts
@@ -62,7 +62,7 @@ Object.defineProperty(singletonRouter, 'events', {
   },
 })
 
-urlPropertyFields.forEach(field => {
+urlPropertyFields.forEach((field) => {
   // Here we need to use Object.defineProperty because, we need to return
   // the property assigned to the actual router
   // The value might get changed as we change routes and this is the
@@ -75,7 +75,7 @@ urlPropertyFields.forEach(field => {
   })
 })
 
-coreMethodFields.forEach(field => {
+coreMethodFields.forEach((field) => {
   // We don't really know the types here, so we add them later instead
   ;(singletonRouter as any)[field] = (...args: any[]) => {
     const router = getRouter() as any
@@ -83,7 +83,7 @@ coreMethodFields.forEach(field => {
   }
 })
 
-routerEvents.forEach(event => {
+routerEvents.forEach((event) => {
   singletonRouter.ready(() => {
     Router.events.on(event, (...args) => {
       const eventField = `on${event.charAt(0).toUpperCase()}${event.substring(
@@ -133,7 +133,7 @@ export function useRouter(): NextRouter {
 // This should **not** use inside the server.
 export const createRouter = (...args: RouterArgs): Router => {
   singletonRouter.router = new Router(...args)
-  singletonRouter.readyCallbacks.forEach(cb => cb())
+  singletonRouter.readyCallbacks.forEach((cb) => cb())
   singletonRouter.readyCallbacks = []
 
   return singletonRouter.router
@@ -156,7 +156,7 @@ export function makePublicRouterInstance(router: Router): NextRouter {
   // Events is a static property on the router, the router doesn't have to be initialized to use it
   instance.events = Router.events
 
-  coreMethodFields.forEach(field => {
+  coreMethodFields.forEach((field) => {
     instance[field] = (...args: any[]) => {
       return _router[field](...args)
     }
diff --git a/packages/next/export/index.ts b/packages/next/export/index.ts
index d63f5e5ff5..53df3a5e39 100644
--- a/packages/next/export/index.ts
+++ b/packages/next/export/index.ts
@@ -84,7 +84,7 @@ type ExportPathMap = {
   [page: string]: { page: string; query?: { [key: string]: string } }
 }
 
-export default async function(
+export default async function (
   dir: string,
   options: any,
   configuration?: any
@@ -270,7 +270,7 @@ export default async function(
   const exportPaths = Object.keys(exportPathMap)
   const filteredPaths = exportPaths.filter(
     // Remove API routes
-    route => !exportPathMap[route].page.match(API_ROUTE)
+    (route) => !exportPathMap[route].page.match(API_ROUTE)
   )
 
   if (filteredPaths.length !== exportPaths.length) {
@@ -335,7 +335,7 @@ export default async function(
   let renderError = false
 
   await Promise.all(
-    filteredPaths.map(async path => {
+    filteredPaths.map(async (path) => {
       const result = await worker.default({
         path,
         pathMap: exportPathMap[path],
@@ -375,7 +375,7 @@ export default async function(
   // copy prerendered routes to outDir
   if (!options.buildExport && prerenderManifest) {
     await Promise.all(
-      Object.keys(prerenderManifest.routes).map(async route => {
+      Object.keys(prerenderManifest.routes).map(async (route) => {
         route = normalizePagePath(route)
         const orig = join(distPagesDir, route)
         const htmlDest = join(
diff --git a/packages/next/export/worker.js b/packages/next/export/worker.js
index f79ef0188f..ada5065217 100644
--- a/packages/next/export/worker.js
+++ b/packages/next/export/worker.js
@@ -17,7 +17,7 @@ global.__NEXT_DATA__ = {
   nextExport: true,
 }
 
-export default async function({
+export default async function ({
   path,
   pathMap,
   distDir,
@@ -115,7 +115,7 @@ export default async function({
     let curRenderOpts = {}
     let renderMethod = renderToHTML
 
-    const renderedDuringBuild = getStaticProps => {
+    const renderedDuringBuild = (getStaticProps) => {
       return !buildExport && getStaticProps && !isDynamicRoute(path)
     }
 
@@ -206,8 +206,8 @@ export default async function({
     const validateAmp = async (html, page, validatorPath) => {
       const validator = await AmpHtmlValidator.getInstance(validatorPath)
       const result = validator.validateString(html)
-      const errors = result.errors.filter(e => e.severity === 'ERROR')
-      const warnings = result.errors.filter(e => e.severity !== 'ERROR')
+      const errors = result.errors.filter((e) => e.severity === 'ERROR')
+      const warnings = result.errors.filter((e) => e.severity !== 'ERROR')
 
       if (warnings.length || errors.length) {
         results.ampValidations.push({
diff --git a/packages/next/lib/check-custom-routes.ts b/packages/next/lib/check-custom-routes.ts
index 9670480a94..c0f23cfb48 100644
--- a/packages/next/lib/check-custom-routes.ts
+++ b/packages/next/lib/check-custom-routes.ts
@@ -85,8 +85,9 @@ function tryParsePath(route: string, handleUrl?: boolean): ParseAttemptResult {
   try {
     if (handleUrl) {
       const parsedDestination = parseUrl(route, true)
-      routePath = `${parsedDestination.pathname!}${parsedDestination.hash ||
-        ''}`
+      routePath = `${parsedDestination.pathname!}${
+        parsedDestination.hash || ''
+      }`
     }
 
     // Make sure we can parse the source properly
@@ -160,7 +161,7 @@ export default function checkCustomRoutes(
     }
 
     const keys = Object.keys(route)
-    const invalidKeys = keys.filter(key => !allowedKeys.has(key))
+    const invalidKeys = keys.filter((key) => !allowedKeys.has(key))
     const invalidParts: string[] = []
 
     if (!route.source) {
@@ -243,7 +244,7 @@ export default function checkCustomRoutes(
           } else {
             const sourceSegments = new Set(
               sourceTokens
-                .map(item => typeof item === 'object' && item.name)
+                .map((item) => typeof item === 'object' && item.name)
                 .filter(Boolean)
             )
             const invalidDestSegments = new Set()
diff --git a/packages/next/lib/coalesced-function.ts b/packages/next/lib/coalesced-function.ts
index d75a0c2ff3..6c2c2a2381 100644
--- a/packages/next/lib/coalesced-function.ts
+++ b/packages/next/lib/coalesced-function.ts
@@ -13,10 +13,10 @@ export function withCoalescedInvoke<F extends (...args: any) => any>(
   key: string,
   args: Parameters<F>
 ) => Promise<CoalescedInvoke<UnwrapPromise<ReturnType<F>>>> {
-  return async function(key: string, args: Parameters<F>) {
+  return async function (key: string, args: Parameters<F>) {
     const entry = globalInvokeCache.get(key)
     if (entry) {
-      return entry.then(res => ({
+      return entry.then((res) => ({
         isOrigin: false,
         value: res.value as UnwrapPromise<ReturnType<F>>,
       }))
@@ -27,11 +27,11 @@ export function withCoalescedInvoke<F extends (...args: any) => any>(
     }
 
     const future = __wrapper()
-      .then(res => {
+      .then((res) => {
         globalInvokeCache.delete(key)
         return { isOrigin: true, value: res as UnwrapPromise<ReturnType<F>> }
       })
-      .catch(err => {
+      .catch((err) => {
         globalInvokeCache.delete(key)
         return Promise.reject(err)
       })
diff --git a/packages/next/lib/is-serializable-props.ts b/packages/next/lib/is-serializable-props.ts
index 0a45620bcb..5d9e4241d4 100644
--- a/packages/next/lib/is-serializable-props.ts
+++ b/packages/next/lib/is-serializable-props.ts
@@ -29,9 +29,9 @@ export function isSerializableProps(
         page,
         method,
         path,
-        `Circular references cannot be expressed in JSON (references: \`${visited.get(
-          value
-        ) || '(self)'}\`).`
+        `Circular references cannot be expressed in JSON (references: \`${
+          visited.get(value) || '(self)'
+        }\`).`
       )
     }
 
diff --git a/packages/next/lib/recursive-copy.ts b/packages/next/lib/recursive-copy.ts
index 490a48ad6c..cc8a934dd9 100644
--- a/packages/next/lib/recursive-copy.ts
+++ b/packages/next/lib/recursive-copy.ts
@@ -40,7 +40,7 @@ export async function recursiveCopy(
       }
       sema.release()
       const files = await promises.readdir(item)
-      await Promise.all(files.map(file => _copy(path.join(item, file))))
+      await Promise.all(files.map((file) => _copy(path.join(item, file))))
     } else if (
       stats.isFile() &&
       // before we send the path to filter
diff --git a/packages/next/lib/recursive-delete.ts b/packages/next/lib/recursive-delete.ts
index 5570dcb527..46d108922b 100644
--- a/packages/next/lib/recursive-delete.ts
+++ b/packages/next/lib/recursive-delete.ts
@@ -52,7 +52,7 @@ export async function recursiveDelete(
   await Promise.all(
     result.map(async (part: string) => {
       const absolutePath = join(dir, part)
-      const pathStat = await promises.stat(absolutePath).catch(e => {
+      const pathStat = await promises.stat(absolutePath).catch((e) => {
         if (e.code !== 'ENOENT') throw e
       })
       if (!pathStat) {
diff --git a/packages/next/lib/verifyTypeScriptSetup.ts b/packages/next/lib/verifyTypeScriptSetup.ts
index 02189f67dc..b66c6518b2 100644
--- a/packages/next/lib/verifyTypeScriptSetup.ts
+++ b/packages/next/lib/verifyTypeScriptSetup.ts
@@ -39,7 +39,7 @@ async function checkDependencies({
 
   let resolutions = new Map<string, string>()
 
-  const missingPackages = requiredPackages.filter(p => {
+  const missingPackages = requiredPackages.filter((p) => {
     try {
       resolutions.set(p.pkg, resolveRequest(p.file, `${dir}/`))
       return false
@@ -64,7 +64,7 @@ async function checkDependencies({
           : '') + p.pkg
     )
     .join('')
-  const packagesCli = missingPackages.map(p => p.pkg).join(' ')
+  const packagesCli = missingPackages.map((p) => p.pkg).join(' ')
 
   console.error(
     chalk.bold.red(
@@ -107,7 +107,7 @@ export async function verifyTypeScriptSetup(
   if (hasTsConfig) {
     const tsConfig = await fs.promises
       .readFile(tsConfigPath, 'utf8')
-      .then(val => val.trim())
+      .then((val) => val.trim())
     firstTimeSetup = tsConfig === '' || tsConfig === '{}'
   } else {
     const hasTypeScriptFiles = await hasTypeScript(pagesDir)
@@ -294,7 +294,7 @@ export async function verifyTypeScriptSetup(
           'file:'
         )
       )
-      messages.forEach(message => {
+      messages.forEach((message) => {
         console.warn('  - ' + message)
       })
       console.warn()
diff --git a/packages/next/next-server/lib/dynamic.tsx b/packages/next/next-server/lib/dynamic.tsx
index 930705dedf..ed8cac994f 100644
--- a/packages/next/next-server/lib/dynamic.tsx
+++ b/packages/next/next-server/lib/dynamic.tsx
@@ -138,7 +138,7 @@ export default function dynamic<P = {}>(
       loadableFn = Loadable.Map
       const loadModules: LoaderMap = {}
       const modules = dynamicOptions.modules()
-      Object.keys(modules).forEach(key => {
+      Object.keys(modules).forEach((key) => {
         const value: any = modules[key]
         if (typeof value.then === 'function') {
           loadModules[key] = () => value.then((mod: any) => mod.default || mod)
diff --git a/packages/next/next-server/lib/head.tsx b/packages/next/next-server/lib/head.tsx
index b5d501a191..d13189cfe9 100644
--- a/packages/next/next-server/lib/head.tsx
+++ b/packages/next/next-server/lib/head.tsx
@@ -149,9 +149,9 @@ const Effect = withSideEffect()
 function Head({ children }: { children: React.ReactNode }) {
   return (
     <AmpStateContext.Consumer>
-      {ampState => (
+      {(ampState) => (
         <HeadManagerContext.Consumer>
-          {updateHead => (
+          {(updateHead) => (
             <Effect
               reduceComponentsToState={reduceComponents}
               handleStateChange={updateHead}
diff --git a/packages/next/next-server/lib/loadable.js b/packages/next/next-server/lib/loadable.js
index 307d23ba09..d399f37ce9 100644
--- a/packages/next/next-server/lib/loadable.js
+++ b/packages/next/next-server/lib/loadable.js
@@ -39,12 +39,12 @@ function load(loader) {
   }
 
   state.promise = promise
-    .then(loaded => {
+    .then((loaded) => {
       state.loading = false
       state.loaded = loaded
       return loaded
     })
-    .catch(err => {
+    .catch((err) => {
       state.loading = false
       state.error = err
       throw err
@@ -63,7 +63,7 @@ function loadMap(obj) {
   let promises = []
 
   try {
-    Object.keys(obj).forEach(key => {
+    Object.keys(obj).forEach((key) => {
       let result = load(obj[key])
 
       if (!result.loading) {
@@ -76,10 +76,10 @@ function loadMap(obj) {
       promises.push(result.promise)
 
       result.promise
-        .then(res => {
+        .then((res) => {
           state.loaded[key] = res
         })
-        .catch(err => {
+        .catch((err) => {
           state.error = err
         })
     })
@@ -88,11 +88,11 @@ function loadMap(obj) {
   }
 
   state.promise = Promise.all(promises)
-    .then(res => {
+    .then((res) => {
       state.loading = false
       return res
     })
-    .catch(err => {
+    .catch((err) => {
       state.loading = false
       throw err
     })
@@ -149,7 +149,7 @@ function createLoadableComponent(loadFn, options) {
     typeof opts.webpack === 'function'
   ) {
     const moduleIds = opts.webpack()
-    READY_INITIALIZERS.push(ids => {
+    READY_INITIALIZERS.push((ids) => {
       for (const moduleId of moduleIds) {
         if (ids.indexOf(moduleId) !== -1) {
           return init()
@@ -173,7 +173,7 @@ function createLoadableComponent(loadFn, options) {
     )
 
     if (context && Array.isArray(opts.modules)) {
-      opts.modules.forEach(moduleName => {
+      opts.modules.forEach((moduleName) => {
         context(moduleName)
       })
     }
@@ -253,7 +253,7 @@ class LoadableSubscription {
         this._clearTimeouts()
       })
       // eslint-disable-next-line handle-callback-err
-      .catch(err => {
+      .catch((err) => {
         this._update({})
         this._clearTimeouts()
       })
@@ -268,7 +268,7 @@ class LoadableSubscription {
       loading: this._res.loading,
       ...partial,
     }
-    this._callbacks.forEach(callback => callback())
+    this._callbacks.forEach((callback) => callback())
   }
 
   _clearTimeouts() {
@@ -324,7 +324,7 @@ Loadable.preloadAll = () => {
 }
 
 Loadable.preloadReady = (ids = []) => {
-  return new Promise(resolve => {
+  return new Promise((resolve) => {
     const res = () => {
       initialized = true
       return resolve()
diff --git a/packages/next/next-server/lib/router/router.ts b/packages/next/next-server/lib/router/router.ts
index e9b09e4465..b64cdf0ee2 100644
--- a/packages/next/next-server/lib/router/router.ts
+++ b/packages/next/next-server/lib/router/router.ts
@@ -111,7 +111,7 @@ function fetchNextData(
         // https://github.com/github/fetch#caveats
         credentials: 'same-origin',
       }
-    ).then(res => {
+    ).then((res) => {
       if (!res.ok) {
         if (--attempts > 0 && res.status >= 500) {
           return getResponse()
@@ -123,7 +123,7 @@ function fetchNextData(
   }
 
   return getResponse()
-    .then(data => {
+    .then((data) => {
       return cb ? cb(data) : data
     })
     .catch((err: Error) => {
@@ -440,7 +440,7 @@ export default class Router implements BaseRouter {
         const routeMatch = getRouteMatcher(routeRegex)(asPathname)
         if (!routeMatch) {
           const missingParams = Object.keys(routeRegex.groups).filter(
-            param => !query[param]
+            (param) => !query[param]
           )
 
           if (missingParams.length > 0) {
@@ -469,33 +469,36 @@ export default class Router implements BaseRouter {
       Router.events.emit('routeChangeStart', as)
 
       // If shallow is true and the route exists in the router cache we reuse the previous result
-      this.getRouteInfo(route, pathname, query, as, shallow).then(routeInfo => {
-        const { error } = routeInfo
+      this.getRouteInfo(route, pathname, query, as, shallow).then(
+        (routeInfo) => {
+          const { error } = routeInfo
 
-        if (error && error.cancelled) {
-          return resolve(false)
-        }
+          if (error && error.cancelled) {
+            return resolve(false)
+          }
 
-        Router.events.emit('beforeHistoryChange', as)
-        this.changeState(method, url, as, options)
+          Router.events.emit('beforeHistoryChange', as)
+          this.changeState(method, url, as, options)
 
-        if (process.env.NODE_ENV !== 'production') {
-          const appComp: any = this.components['/_app'].Component
-          ;(window as any).next.isPrerendered =
-            appComp.getInitialProps === appComp.origGetInitialProps &&
-            !(routeInfo.Component as any).getInitialProps
-        }
+          if (process.env.NODE_ENV !== 'production') {
+            const appComp: any = this.components['/_app'].Component
+            ;(window as any).next.isPrerendered =
+              appComp.getInitialProps === appComp.origGetInitialProps &&
+              !(routeInfo.Component as any).getInitialProps
+          }
 
-        this.set(route, pathname, query, as, routeInfo)
+          this.set(route, pathname, query, as, routeInfo)
 
-        if (error) {
-          Router.events.emit('routeChangeError', error, as)
-          throw error
-        }
+          if (error) {
+            Router.events.emit('routeChangeError', error, as)
+            throw error
+          }
 
-        Router.events.emit('routeChangeComplete', as)
-        return resolve(true)
-      }, reject)
+          Router.events.emit('routeChangeComplete', as)
+          return resolve(true)
+        },
+        reject
+      )
     })
   }
 
@@ -552,7 +555,7 @@ export default class Router implements BaseRouter {
       err: Error & { code: any; cancelled: boolean },
       loadErrorFail?: boolean
     ) => {
-      return new Promise(resolve => {
+      return new Promise((resolve) => {
         if (err.code === 'PAGE_LOAD_ERROR' || loadErrorFail) {
           // If we can't load the page it could be one of following reasons
           //  1. Page doesn't exists
@@ -576,21 +579,21 @@ export default class Router implements BaseRouter {
 
         resolve(
           this.fetchComponent('/_error')
-            .then(res => {
+            .then((res) => {
               const { page: Component } = res
               const routeInfo: RouteInfo = { Component, err }
-              return new Promise(resolve => {
+              return new Promise((resolve) => {
                 this.getInitialProps(Component, {
                   err,
                   pathname,
                   query,
                 } as any).then(
-                  props => {
+                  (props) => {
                     routeInfo.props = props
                     routeInfo.error = err
                     resolve(routeInfo)
                   },
-                  gipErr => {
+                  (gipErr) => {
                     console.error(
                       'Error in error page `getInitialProps`: ',
                       gipErr
@@ -602,7 +605,7 @@ export default class Router implements BaseRouter {
                 )
               }) as Promise<RouteInfo>
             })
-            .catch(err => handleError(err, true))
+            .catch((err) => handleError(err, true))
         )
       }) as Promise<RouteInfo>
     }
@@ -613,7 +616,7 @@ export default class Router implements BaseRouter {
       }
 
       this.fetchComponent(route).then(
-        res =>
+        (res) =>
           resolve({
             Component: res.page,
             __N_SSG: res.mod.__N_SSG,
@@ -648,7 +651,7 @@ export default class Router implements BaseRouter {
                   asPath: as,
                 } as any
               )
-        ).then(props => {
+        ).then((props) => {
           routeInfo.props = props
           this.components[route] = routeInfo
           return routeInfo
@@ -794,7 +797,7 @@ export default class Router implements BaseRouter {
       cancelled = true
     }
     this.clc = cancel
-    return fn().then(data => {
+    return fn().then((data) => {
       if (cancel === this.clc) {
         this.clc = null
       }
@@ -818,7 +821,7 @@ export default class Router implements BaseRouter {
           pathname,
           null,
           this.isSsr,
-          data => (this.sdc[pathname] = data)
+          (data) => (this.sdc[pathname] = data)
         )
   }
 
diff --git a/packages/next/next-server/lib/router/utils/route-matcher.ts b/packages/next/next-server/lib/router/utils/route-matcher.ts
index 709760962d..b3faafb1b2 100644
--- a/packages/next/next-server/lib/router/utils/route-matcher.ts
+++ b/packages/next/next-server/lib/router/utils/route-matcher.ts
@@ -26,7 +26,7 @@ export function getRouteMatcher(routeRegex: ReturnType<typeof getRouteRegex>) {
       const m = routeMatch[g.pos]
       if (m !== undefined) {
         params[slugName] = ~m.indexOf('/')
-          ? m.split('/').map(entry => decode(entry))
+          ? m.split('/').map((entry) => decode(entry))
           : g.repeat
           ? [decode(m)]
           : decode(m)
diff --git a/packages/next/next-server/lib/router/utils/sorted-routes.ts b/packages/next/next-server/lib/router/utils/sorted-routes.ts
index 6100f0f1c5..6d18b36271 100644
--- a/packages/next/next-server/lib/router/utils/sorted-routes.ts
+++ b/packages/next/next-server/lib/router/utils/sorted-routes.ts
@@ -26,7 +26,7 @@ class UrlNode {
     }
 
     const routes = childrenPaths
-      .map(c => this.children.get(c)!._smoosh(`${prefix}${c}/`))
+      .map((c) => this.children.get(c)!._smoosh(`${prefix}${c}/`))
       .reduce((prev, curr) => [...prev, ...curr], [])
 
     if (this.slugName !== null) {
@@ -202,7 +202,7 @@ export function getSortedRoutes(normalizedPages: string[]): string[] {
   const root = new UrlNode()
 
   // Here the `root` gets injected multiple paths, and insert will break them up into sublevels
-  normalizedPages.forEach(pagePath => root.insert(pagePath))
+  normalizedPages.forEach((pagePath) => root.insert(pagePath))
   // Smoosh will then sort those sublevels up to the point where you get the correct route definition priority
   return root.smoosh()
 }
diff --git a/packages/next/next-server/lib/utils.ts b/packages/next/next-server/lib/utils.ts
index ee336d7332..c29adc6699 100644
--- a/packages/next/next-server/lib/utils.ts
+++ b/packages/next/next-server/lib/utils.ts
@@ -350,7 +350,7 @@ export function formatWithValidation(
 ) {
   if (process.env.NODE_ENV === 'development') {
     if (url !== null && typeof url === 'object') {
-      Object.keys(url).forEach(key => {
+      Object.keys(url).forEach((key) => {
         if (urlObjectKeys.indexOf(key) === -1) {
           console.warn(
             `Unknown key passed via urlObject into url.format: ${key}`
diff --git a/packages/next/next-server/server/api-utils.ts b/packages/next/next-server/server/api-utils.ts
index d062557610..bbc57d0894 100644
--- a/packages/next/next-server/server/api-utils.ts
+++ b/packages/next/next-server/server/api-utils.ts
@@ -53,9 +53,9 @@ export async function apiResolver(
       )
     }
 
-    apiRes.status = statusCode => sendStatusCode(apiRes, statusCode)
-    apiRes.send = data => sendData(apiRes, data)
-    apiRes.json = data => sendJson(apiRes, data)
+    apiRes.status = (statusCode) => sendStatusCode(apiRes, statusCode)
+    apiRes.send = (data) => sendData(apiRes, data)
+    apiRes.json = (data) => sendJson(apiRes, data)
     apiRes.setPreviewData = (data, options = {}) =>
       setPreviewData(apiRes, data, Object.assign({}, apiContext, options))
     apiRes.clearPreviewData = () => clearPreviewData(apiRes)
@@ -523,7 +523,7 @@ export function setLazyProp<T>(
       Object.defineProperty(req, prop, { ...optsReset, value })
       return value
     },
-    set: value => {
+    set: (value) => {
       Object.defineProperty(req, prop, { ...optsReset, value })
     },
   })
diff --git a/packages/next/next-server/server/config.ts b/packages/next/next-server/server/config.ts
index 528e3ce6b2..50d3e18e9a 100644
--- a/packages/next/next-server/server/config.ts
+++ b/packages/next/next-server/server/config.ts
@@ -124,7 +124,7 @@ function assignDefaults(userConfig: { [key: string]: any }) {
         )
       }
 
-      pageExtensions.forEach(ext => {
+      pageExtensions.forEach((ext) => {
         if (typeof ext !== 'string') {
           throw new Error(
             `Specified pageExtensions is not an array of strings, found "${ext}" of type "${typeof ext}". Please update this config or remove it.`
diff --git a/packages/next/next-server/server/next-server.ts b/packages/next/next-server/server/next-server.ts
index 868fcef591..7ce91183e2 100644
--- a/packages/next/next-server/server/next-server.ts
+++ b/packages/next/next-server/server/next-server.ts
@@ -492,7 +492,7 @@ export default class Server {
       }
 
       // Headers come very first
-      headers = this.customRoutes.headers.map(r => {
+      headers = this.customRoutes.headers.map((r) => {
         const route = getCustomRoute(r, 'header')
         return {
           match: route.match,
@@ -514,7 +514,7 @@ export default class Server {
         } as Route
       })
 
-      redirects = this.customRoutes.redirects.map(redirect => {
+      redirects = this.customRoutes.redirects.map((redirect) => {
         const route = getCustomRoute(redirect, 'redirect')
         return {
           type: route.type,
@@ -546,7 +546,7 @@ export default class Server {
         } as Route
       })
 
-      rewrites = this.customRoutes.rewrites.map(rewrite => {
+      rewrites = this.customRoutes.rewrites.map((rewrite) => {
         const route = getCustomRoute(rewrite, 'rewrite')
         return {
           check: true,
@@ -726,7 +726,7 @@ export default class Server {
 
   protected generatePublicRoutes(): Route[] {
     const publicFiles = new Set(
-      recursiveReadDirSync(this.publicDir).map(p => p.replace(/\\/g, '/'))
+      recursiveReadDirSync(this.publicDir).map((p) => p.replace(/\\/g, '/'))
     )
 
     return [
@@ -760,7 +760,7 @@ export default class Server {
   protected getDynamicRoutes() {
     return getSortedRoutes(Object.keys(this.pagesManifest!))
       .filter(isDynamicRoute)
-      .map(page => ({
+      .map((page) => ({
         page,
         match: getRouteMatcher(getRouteRegex(page)),
       }))
@@ -1078,7 +1078,7 @@ export default class Server {
           return { isOrigin: true, value }
         }
 
-    const doRender = maybeCoalesceInvoke(async function(): Promise<{
+    const doRender = maybeCoalesceInvoke(async function (): Promise<{
       html: string | null
       pageData: any
       sprRevalidate: number | false
@@ -1411,14 +1411,14 @@ export default class Server {
     const pathUserFilesStatic = join(this.dir, 'static')
     let userFilesStatic: string[] = []
     if (this.hasStaticDir && fs.existsSync(pathUserFilesStatic)) {
-      userFilesStatic = recursiveReadDirSync(pathUserFilesStatic).map(f =>
+      userFilesStatic = recursiveReadDirSync(pathUserFilesStatic).map((f) =>
         join('.', 'static', f)
       )
     }
 
     let userFilesPublic: string[] = []
     if (this.publicDir && fs.existsSync(this.publicDir)) {
-      userFilesPublic = recursiveReadDirSync(this.publicDir).map(f =>
+      userFilesPublic = recursiveReadDirSync(this.publicDir).map((f) =>
         join('.', 'public', f)
       )
     }
@@ -1426,7 +1426,7 @@ export default class Server {
     let nextFilesStatic: string[] = []
     nextFilesStatic = recursiveReadDirSync(
       join(this.distDir, 'static')
-    ).map(f => join('.', relative(this.dir, this.distDir), 'static', f))
+    ).map((f) => join('.', relative(this.dir, this.distDir), 'static', f))
 
     return (this._validFilesystemPathSet = new Set<string>([
       ...nextFilesStatic,
diff --git a/packages/next/next-server/server/render.tsx b/packages/next/next-server/server/render.tsx
index 1c48855f40..d3eca865e6 100644
--- a/packages/next/next-server/server/render.tsx
+++ b/packages/next/next-server/server/render.tsx
@@ -492,7 +492,7 @@ export async function renderToHTML(
     <RouterContext.Provider value={router}>
       <AmpStateContext.Provider value={ampState}>
         <LoadableContext.Provider
-          value={moduleName => reactLoadableModules.push(moduleName)}
+          value={(moduleName) => reactLoadableModules.push(moduleName)}
         >
           {children}
         </LoadableContext.Provider>
@@ -541,7 +541,7 @@ export async function renderToHTML(
       }
 
       const invalidKeys = Object.keys(data).filter(
-        key => key !== 'unstable_revalidate' && key !== 'props'
+        (key) => key !== 'unstable_revalidate' && key !== 'props'
       )
 
       if (invalidKeys.includes('revalidate')) {
@@ -626,7 +626,7 @@ export async function renderToHTML(
         throw err
       }
 
-      const invalidKeys = Object.keys(data).filter(key => key !== 'props')
+      const invalidKeys = Object.keys(data).filter((key) => key !== 'props')
 
       if (invalidKeys.length) {
         throw new Error(invalidKeysMsg('getServerSideProps', invalidKeys))
@@ -748,7 +748,7 @@ export async function renderToHTML(
     const manifestItem: ManifestItem[] = reactLoadableManifest[mod]
 
     if (manifestItem) {
-      manifestItem.forEach(item => {
+      manifestItem.forEach((item) => {
         dynamicImports.push(item)
         dynamicImportIdsSet.add(item.id as string)
       })
diff --git a/packages/next/pages/_document.tsx b/packages/next/pages/_document.tsx
index d2852921bd..1ba5e18f7e 100644
--- a/packages/next/pages/_document.tsx
+++ b/packages/next/pages/_document.tsx
@@ -79,7 +79,7 @@ export default class Document<P = {}> extends Component<DocumentProps & P> {
       ? await import(
           // @ts-ignore loader syntax
           'next-plugin-loader?middleware=unstable-enhance-app-server!'
-        ).then(mod => mod.default(ctx))
+        ).then((mod) => mod.default(ctx))
       : []
 
     const enhanceApp = (App: any) => {
@@ -96,7 +96,7 @@ export default class Document<P = {}> extends Component<DocumentProps & P> {
         ? await import(
             // @ts-ignore loader syntax
             'next-plugin-loader?middleware=unstable-get-styles-server!'
-          ).then(mod => mod.default(ctx))
+          ).then((mod) => mod.default(ctx))
         : []),
     ]
     return { html, head, styles }
@@ -184,10 +184,10 @@ export class Head extends Component<
     const { assetPrefix, files } = this.context._documentProps
     const { _devOnlyInvalidateCacheQueryString } = this.context
     const cssFiles =
-      files && files.length ? files.filter(f => /\.css$/.test(f)) : []
+      files && files.length ? files.filter((f) => /\.css$/.test(f)) : []
 
     const cssLinkElements: JSX.Element[] = []
-    cssFiles.forEach(file => {
+    cssFiles.forEach((file) => {
       cssLinkElements.push(
         <link
           key={`${file}-preload`}
@@ -316,7 +316,7 @@ export class Head extends Component<
     let hasCanonicalRel = false
 
     // show warning and remove conflicting amp head tags
-    head = React.Children.map(head || [], child => {
+    head = React.Children.map(head || [], (child) => {
       if (!child) return child
       const { type, props } = child
 
@@ -338,7 +338,7 @@ export class Head extends Component<
               (!props.type || props.type === 'text/javascript'))
           ) {
             badProp = '<script'
-            Object.keys(props).forEach(prop => {
+            Object.keys(props).forEach((prop) => {
               badProp += ` ${prop}="${props[prop]}"`
             })
             badProp += '/>'
@@ -377,7 +377,7 @@ export class Head extends Component<
       // @ts-ignore Property 'props' does not exist on type ReactElement
       styles.props.children.forEach((child: React.ReactElement) => {
         if (Array.isArray(child)) {
-          child.forEach(el => hasStyles(el) && curStyles.push(el))
+          child.forEach((el) => hasStyles(el) && curStyles.push(el))
         } else if (hasStyles(child)) {
           curStyles.push(child)
         }
@@ -437,7 +437,7 @@ export class Head extends Component<
                 amp-custom=""
                 dangerouslySetInnerHTML={{
                   __html: curStyles
-                    .map(style => style.props.dangerouslySetInnerHTML.__html)
+                    .map((style) => style.props.dangerouslySetInnerHTML.__html)
                     .join('')
                     .replace(/\/\*# sourceMappingURL=.*\*\//g, '')
                     .replace(/\/\*@ sourceURL=.*?\*\//g, ''),
@@ -578,12 +578,12 @@ export class NextScript extends Component<OriginProps> {
     const { assetPrefix, files, lowPriorityFiles } = this.context._documentProps
     const { _devOnlyInvalidateCacheQueryString } = this.context
 
-    const normalScripts = files?.filter(file => file.endsWith('.js'))
-    const lowPriorityScripts = lowPriorityFiles?.filter(file =>
+    const normalScripts = files?.filter((file) => file.endsWith('.js'))
+    const lowPriorityScripts = lowPriorityFiles?.filter((file) =>
       file.endsWith('.js')
     )
 
-    return [...normalScripts, ...lowPriorityScripts].map(file => {
+    return [...normalScripts, ...lowPriorityScripts].map((file) => {
       let modernProps = {}
       if (process.env.__NEXT_MODERN_BUILD) {
         modernProps = file.endsWith('.module.js')
@@ -613,9 +613,10 @@ export class NextScript extends Component<OriginProps> {
 
     return polyfillFiles
       .filter(
-        polyfill => polyfill.endsWith('.js') && !/\.module\.js$/.test(polyfill)
+        (polyfill) =>
+          polyfill.endsWith('.js') && !/\.module\.js$/.test(polyfill)
       )
-      .map(polyfill => (
+      .map((polyfill) => (
         <script
           key={polyfill}
           nonce={this.props.nonce}
@@ -683,7 +684,7 @@ export class NextScript extends Component<OriginProps> {
             />
           )}
           {devFiles
-            ? devFiles.map(file => (
+            ? devFiles.map((file) => (
                 <script
                   key={file}
                   src={`${assetPrefix}/_next/${file}${_devOnlyInvalidateCacheQueryString}`}
diff --git a/packages/next/server/hot-reloader.ts b/packages/next/server/hot-reloader.ts
index b9664dfd02..f03240d5f6 100644
--- a/packages/next/server/hot-reloader.ts
+++ b/packages/next/server/hot-reloader.ts
@@ -255,7 +255,7 @@ export default class HotReloader {
     ])
 
     const pages = createPagesMapping(
-      pagePaths.filter(i => i !== null) as string[],
+      pagePaths.filter((i) => i !== null) as string[],
       this.config.pageExtensions
     )
     const entrypoints = createEntrypoints(
@@ -374,7 +374,7 @@ export default class HotReloader {
     // This plugin watches for changes to _document.js and notifies the client side that it should reload the page
     multiCompiler.compilers[1].hooks.done.tap(
       'NextjsHotReloaderForServer',
-      stats => {
+      (stats) => {
         if (!this.initialized) {
           return
         }
@@ -384,7 +384,8 @@ export default class HotReloader {
         // We only watch `_document` for changes on the server compilation
         // the rest of the files will be triggered by the client compilation
         const documentChunk = compilation.chunks.find(
-          c => c.name === normalize(`static/${this.buildId}/pages/_document.js`)
+          (c) =>
+            c.name === normalize(`static/${this.buildId}/pages/_document.js`)
         )
         // If the document chunk can't be found we do nothing
         if (!documentChunk) {
@@ -411,12 +412,12 @@ export default class HotReloader {
 
     multiCompiler.compilers[0].hooks.done.tap(
       'NextjsHotReloaderForClient',
-      stats => {
+      (stats) => {
         const { compilation } = stats
         const chunkNames = new Set(
           compilation.chunks
-            .map(c => c.name)
-            .filter(name => IS_BUNDLED_PAGE_REGEX.test(name))
+            .map((c) => c.name)
+            .filter((name) => IS_BUNDLED_PAGE_REGEX.test(name))
         )
 
         if (this.initialized) {
@@ -514,7 +515,7 @@ export default class HotReloader {
     webpackDevMiddleware?: WebpackDevMiddleware.WebpackDevMiddleware
   ): Promise<webpack.Stats> {
     const middleware = webpackDevMiddleware || this.webpackDevMiddleware
-    return new Promise(resolve => {
+    return new Promise((resolve) => {
       middleware!.waitUntilValid(resolve)
     })
   }
@@ -561,5 +562,5 @@ export default class HotReloader {
 }
 
 function diff(a: Set<any>, b: Set<any>) {
-  return new Set([...a].filter(v => !b.has(v)))
+  return new Set([...a].filter((v) => !b.has(v)))
 }
diff --git a/packages/next/server/htmlescape.ts b/packages/next/server/htmlescape.ts
index 0baabc2348..7bcda3c357 100644
--- a/packages/next/server/htmlescape.ts
+++ b/packages/next/server/htmlescape.ts
@@ -12,5 +12,5 @@ const ESCAPE_LOOKUP: { [match: string]: string } = {
 const ESCAPE_REGEX = /[&><\u2028\u2029]/g
 
 export function htmlEscapeJsonString(str: string): string {
-  return str.replace(ESCAPE_REGEX, match => ESCAPE_LOOKUP[match])
+  return str.replace(ESCAPE_REGEX, (match) => ESCAPE_LOOKUP[match])
 }
diff --git a/packages/next/server/next-dev-server.ts b/packages/next/server/next-dev-server.ts
index f98a8a40e4..3e338d1378 100644
--- a/packages/next/server/next-dev-server.ts
+++ b/packages/next/server/next-dev-server.ts
@@ -49,7 +49,7 @@ export default class DevServer extends Server {
     super({ ...options, dev: true })
     this.renderOpts.dev = true
     ;(this.renderOpts as any).ErrorDebug = ReactDevOverlay
-    this.devReady = new Promise(resolve => {
+    this.devReady = new Promise((resolve) => {
       this.setDevReady = resolve
     })
     ;(this.renderOpts as any).ampSkipValidation =
@@ -62,14 +62,14 @@ export default class DevServer extends Server {
         this.nextConfig.experimental &&
         this.nextConfig.experimental.amp &&
         this.nextConfig.experimental.amp.validator
-      return AmpHtmlValidator.getInstance(validatorPath).then(validator => {
+      return AmpHtmlValidator.getInstance(validatorPath).then((validator) => {
         const result = validator.validateString(html)
         ampValidation(
           pathname,
           result.errors
-            .filter(e => e.severity === 'ERROR')
-            .filter(e => this._filterAmpDevelopmentScript(html, e)),
-          result.errors.filter(e => e.severity !== 'ERROR')
+            .filter((e) => e.severity === 'ERROR')
+            .filter((e) => this._filterAmpDevelopmentScript(html, e)),
+          result.errors.filter((e) => e.severity !== 'ERROR')
         )
       })
     }
@@ -139,8 +139,8 @@ export default class DevServer extends Server {
             const { query: urlQuery } = parsedUrl
 
             Object.keys(urlQuery)
-              .filter(key => query[key] === undefined)
-              .forEach(key =>
+              .filter((key) => query[key] === undefined)
+              .forEach((key) =>
                 console.warn(
                   `Url '${path}' defines a query parameter '${key}' that is missing in exportPathMap`
                 )
@@ -204,13 +204,13 @@ export default class DevServer extends Server {
         try {
           this.dynamicRoutes = getSortedRoutes(routedPages)
             .filter(isDynamicRoute)
-            .map(page => ({
+            .map((page) => ({
               page,
               match: getRouteMatcher(getRouteRegex(page)),
             }))
 
           const firstOptionalCatchAllPage =
-            this.dynamicRoutes.find(f => /\[\[\.{3}[^\][/]*\]\]/.test(f.page))
+            this.dynamicRoutes.find((f) => /\[\[\.{3}[^\][/]*\]\]/.test(f.page))
               ?.page ?? null
           if (
             this.nextConfig.experimental?.optionalCatchAll !== true &&
diff --git a/packages/next/server/on-demand-entry-handler.ts b/packages/next/server/on-demand-entry-handler.ts
index 74b0171dd6..9d1b29f389 100644
--- a/packages/next/server/on-demand-entry-handler.ts
+++ b/packages/next/server/on-demand-entry-handler.ts
@@ -72,7 +72,7 @@ export default function onDemandEntryHandler(
       (compilation: webpack.compilation.Compilation) => {
         invalidator.startBuilding()
 
-        const allEntries = Object.keys(entries).map(async page => {
+        const allEntries = Object.keys(entries).map(async (page) => {
           if (compiler.name === 'client' && page.match(API_ROUTE)) {
             return
           }
@@ -96,14 +96,14 @@ export default function onDemandEntryHandler(
           ])
         })
 
-        return Promise.all(allEntries).catch(err => console.error(err))
+        return Promise.all(allEntries).catch((err) => console.error(err))
       }
     )
   }
 
   function findHardFailedPages(errors: any[]) {
     return errors
-      .filter(e => {
+      .filter((e) => {
         // Make sure to only pick errors which marked with missing modules
         const hasNoModuleFoundError =
           /ENOENT/.test(e.message) || /Module not found/.test(e.message)
@@ -116,7 +116,7 @@ export default function onDemandEntryHandler(
         // So this is a failed page.
         return e.module.dependencies.length === 0
       })
-      .map(e => e.module.chunks)
+      .map((e) => e.module.chunks)
       .reduce((a, b) => [...a, ...b], [])
       .map((c: any) => {
         const pageName = ROUTE_NAME_REGEX.exec(c.name)![1]
@@ -144,7 +144,7 @@ export default function onDemandEntryHandler(
     return pagePaths
   }
 
-  multiCompiler.hooks.done.tap('NextJsOnDemandEntries', multiStats => {
+  multiCompiler.hooks.done.tap('NextJsOnDemandEntries', (multiStats) => {
     const [clientStats, serverStats] = multiStats.stats
     const hardFailedPages = [
       ...new Set([
@@ -198,7 +198,7 @@ export default function onDemandEntryHandler(
     }
   })
 
-  const disposeHandler = setInterval(function() {
+  const disposeHandler = setInterval(function () {
     if (stopped) return
     disposeInactiveEntries(
       devMiddleware,
@@ -254,8 +254,8 @@ export default function onDemandEntryHandler(
   return {
     waitUntilReloaded() {
       if (!reloading) return Promise.resolve(true)
-      return new Promise(resolve => {
-        reloadCallbacks!.once('done', function() {
+      return new Promise((resolve) => {
+        reloadCallbacks!.once('done', function () {
           resolve()
         })
       })
@@ -382,7 +382,7 @@ function disposeInactiveEntries(
 ) {
   const disposingPages: any = []
 
-  Object.keys(entries).forEach(page => {
+  Object.keys(entries).forEach((page) => {
     const { lastActiveTime, status } = entries[page]
 
     // This means this entry is currently building or just added
diff --git a/packages/next/taskfile-babel.js b/packages/next/taskfile-babel.js
index 535b8ceb9e..2e6f0a4ed8 100644
--- a/packages/next/taskfile-babel.js
+++ b/packages/next/taskfile-babel.js
@@ -58,9 +58,9 @@ const babelServerOpts = {
   ],
 }
 
-module.exports = function(task) {
+module.exports = function (task) {
   // eslint-disable-next-line require-yield
-  task.plugin('babel', {}, function*(
+  task.plugin('babel', {}, function* (
     file,
     serverOrClient,
     { stripExtension } = {}
diff --git a/packages/next/taskfile-ncc.js b/packages/next/taskfile-ncc.js
index b07fc42535..63ab094e6e 100644
--- a/packages/next/taskfile-ncc.js
+++ b/packages/next/taskfile-ncc.js
@@ -2,9 +2,9 @@ const ncc = require('@zeit/ncc')
 const { existsSync, readFileSync } = require('fs')
 const { basename, dirname, extname, join } = require('path')
 
-module.exports = function(task) {
+module.exports = function (task) {
   // eslint-disable-next-line require-yield
-  task.plugin('ncc', {}, function*(file, options) {
+  task.plugin('ncc', {}, function* (file, options) {
     if (options.externals && options.packageName) {
       options.externals = { ...options.externals }
       delete options.externals[options.packageName]
@@ -14,7 +14,7 @@ module.exports = function(task) {
       minify: true,
       ...options,
     }).then(({ code, assets }) => {
-      Object.keys(assets).forEach(key => {
+      Object.keys(assets).forEach((key) => {
         let data = assets[key].source
 
         if (join(file.dir, key).endsWith('terser-webpack-plugin/worker.js')) {
diff --git a/packages/next/taskfile-typescript.js b/packages/next/taskfile-typescript.js
index c121d26b50..84f0e47352 100644
--- a/packages/next/taskfile-typescript.js
+++ b/packages/next/taskfile-typescript.js
@@ -15,9 +15,9 @@ try {
     exclude: ['./dist/**', './*.d.ts', './constants.d.ts'],
   }
 
-  module.exports = function(task) {
+  module.exports = function (task) {
     // eslint-disable-next-line require-yield
-    task.plugin('typescript', { every: true }, function*(file, options) {
+    task.plugin('typescript', { every: true }, function* (file, options) {
       const opts = {
         fileName: file.base,
         compilerOptions: {
diff --git a/packages/next/taskfile.js b/packages/next/taskfile.js
index 27492ec0dc..cae8b93b98 100644
--- a/packages/next/taskfile.js
+++ b/packages/next/taskfile.js
@@ -669,24 +669,15 @@ export async function nextbuildstatic(task, opts) {
 }
 
 export async function pages_app(task) {
-  await task
-    .source('pages/_app.tsx')
-    .babel('client')
-    .target('dist/pages')
+  await task.source('pages/_app.tsx').babel('client').target('dist/pages')
 }
 
 export async function pages_error(task) {
-  await task
-    .source('pages/_error.tsx')
-    .babel('client')
-    .target('dist/pages')
+  await task.source('pages/_error.tsx').babel('client').target('dist/pages')
 }
 
 export async function pages_document(task) {
-  await task
-    .source('pages/_document.tsx')
-    .babel('server')
-    .target('dist/pages')
+  await task.source('pages/_document.tsx').babel('server').target('dist/pages')
 }
 
 export async function pages(task, opts) {
@@ -705,7 +696,7 @@ export async function build(task) {
   await task.serial(['precompile', 'compile'])
 }
 
-export default async function(task) {
+export default async function (task) {
   await task.clear('dist')
   await task.start('build')
   await task.watch('bin/*', 'bin')
diff --git a/packages/next/telemetry/events/build.ts b/packages/next/telemetry/events/build.ts
index e2dc948738..22cf1769fc 100644
--- a/packages/next/telemetry/events/build.ts
+++ b/packages/next/telemetry/events/build.ts
@@ -22,11 +22,12 @@ export function eventBuildCompleted(
     payload: {
       ...event,
       totalPageCount: pagePaths.length,
-      hasDunderPages: pagePaths.some(path =>
+      hasDunderPages: pagePaths.some((path) =>
         REGEXP_DIRECTORY_DUNDER.test(path)
       ),
       hasTestPages: pagePaths.some(
-        path => REGEXP_DIRECTORY_TESTS.test(path) || REGEXP_FILE_TEST.test(path)
+        (path) =>
+          REGEXP_DIRECTORY_TESTS.test(path) || REGEXP_FILE_TEST.test(path)
       ),
     },
   }
@@ -57,11 +58,12 @@ export function eventBuildOptimize(
     payload: {
       ...event,
       totalPageCount: pagePaths.length,
-      hasDunderPages: pagePaths.some(path =>
+      hasDunderPages: pagePaths.some((path) =>
         REGEXP_DIRECTORY_DUNDER.test(path)
       ),
       hasTestPages: pagePaths.some(
-        path => REGEXP_DIRECTORY_TESTS.test(path) || REGEXP_FILE_TEST.test(path)
+        (path) =>
+          REGEXP_DIRECTORY_TESTS.test(path) || REGEXP_FILE_TEST.test(path)
       ),
     },
   }
diff --git a/packages/next/telemetry/post-payload.ts b/packages/next/telemetry/post-payload.ts
index 7177a671df..189d1738e5 100644
--- a/packages/next/telemetry/post-payload.ts
+++ b/packages/next/telemetry/post-payload.ts
@@ -10,7 +10,7 @@ export function _postPayload(endpoint: string, body: object) {
           body: JSON.stringify(body),
           headers: { 'content-type': 'application/json' },
           timeout: 5000,
-        }).then(res => {
+        }).then((res) => {
           if (!res.ok) {
             const err = new Error(res.statusText)
             ;(err as any).response = res
diff --git a/packages/next/telemetry/storage.ts b/packages/next/telemetry/storage.ts
index abf2dccb0c..d1565d874f 100644
--- a/packages/next/telemetry/storage.ts
+++ b/packages/next/telemetry/storage.ts
@@ -167,18 +167,18 @@ export class Telemetry {
     }
 
     const prom = wrapper()
-      .then(value => ({
+      .then((value) => ({
         isFulfilled: true,
         isRejected: false,
         value,
       }))
-      .catch(reason => ({
+      .catch((reason) => ({
         isFulfilled: false,
         isRejected: true,
         reason,
       }))
       // Acts as `Promise#finally` because `catch` transforms the error
-      .then(res => {
+      .then((res) => {
         // Clean up the event to prevent unbounded `Set` growth
         this.queue.delete(prom)
         return res
diff --git a/packages/react-dev-overlay/src/internal/ReactDevOverlay.tsx b/packages/react-dev-overlay/src/internal/ReactDevOverlay.tsx
index b0b47c9081..8eeceeb07b 100644
--- a/packages/react-dev-overlay/src/internal/ReactDevOverlay.tsx
+++ b/packages/react-dev-overlay/src/internal/ReactDevOverlay.tsx
@@ -48,7 +48,7 @@ function ReactDevOverlay({ children }) {
 
   React.useEffect(() => {
     Bus.on(dispatch)
-    return function() {
+    return function () {
       Bus.off(dispatch)
     }
   }, [dispatch])
@@ -79,13 +79,9 @@ function ReactDevOverlay({ children }) {
             <BuildError message={state.buildError} />
           ) : hasRuntimeErrors ? (
             <Errors errors={state.errors} />
-          ) : (
-            undefined
-          )}
+          ) : undefined}
         </ShadowPortal>
-      ) : (
-        undefined
-      )}
+      ) : undefined}
     </React.Fragment>
   )
 }
diff --git a/packages/react-dev-overlay/src/internal/bus.ts b/packages/react-dev-overlay/src/internal/bus.ts
index 0bc18b783b..b2a4fc213c 100644
--- a/packages/react-dev-overlay/src/internal/bus.ts
+++ b/packages/react-dev-overlay/src/internal/bus.ts
@@ -37,7 +37,7 @@ let queue: BusEvent[] = []
 function drain() {
   // Draining should never happen synchronously in case multiple handlers are
   // registered.
-  setTimeout(function() {
+  setTimeout(function () {
     while (
       // Until we are out of events:
       Boolean(queue.length) &&
@@ -46,7 +46,7 @@ function drain() {
       Boolean(handlers.size)
     ) {
       const ev = queue.shift()
-      handlers.forEach(handler => handler(ev))
+      handlers.forEach((handler) => handler(ev))
     }
   }, 1)
 }
diff --git a/packages/react-dev-overlay/src/internal/components/CodeFrame/CodeFrame.tsx b/packages/react-dev-overlay/src/internal/components/CodeFrame/CodeFrame.tsx
index e54d1f0b6b..375739395c 100644
--- a/packages/react-dev-overlay/src/internal/components/CodeFrame/CodeFrame.tsx
+++ b/packages/react-dev-overlay/src/internal/components/CodeFrame/CodeFrame.tsx
@@ -14,9 +14,9 @@ export const CodeFrame: React.FC<CodeFrameProps> = function CodeFrame({
   const formattedFrame = React.useMemo<string>(() => {
     const lines = codeFrame.split(/\r?\n/g)
     const prefixLength = lines
-      .map(line => /^>? +\d+ +\| ( *)/.exec(stripAnsi(line)))
+      .map((line) => /^>? +\d+ +\| ( *)/.exec(stripAnsi(line)))
       .filter(Boolean)
-      .map(v => v.pop())
+      .map((v) => v.pop())
       .reduce((c, n) => (isNaN(c) ? n.length : Math.min(c, n.length)), NaN)
 
     if (prefixLength > 1) {
diff --git a/packages/react-dev-overlay/src/internal/components/Dialog/Dialog.tsx b/packages/react-dev-overlay/src/internal/components/Dialog/Dialog.tsx
index 13a886b391..3ca74bb08e 100644
--- a/packages/react-dev-overlay/src/internal/components/Dialog/Dialog.tsx
+++ b/packages/react-dev-overlay/src/internal/components/Dialog/Dialog.tsx
@@ -15,7 +15,7 @@ const Dialog: React.FC<DialogProps> = function Dialog({
   ...props
 }) {
   const [dialog, setDialog] = React.useState<HTMLDivElement>(null)
-  const onDialog = React.useCallback(node => {
+  const onDialog = React.useCallback((node) => {
     setDialog(node)
   }, [])
   useOnClickOutside(dialog, onClose)
diff --git a/packages/react-dev-overlay/src/internal/components/LeftRightDialogHeader/LeftRightDialogHeader.tsx b/packages/react-dev-overlay/src/internal/components/LeftRightDialogHeader/LeftRightDialogHeader.tsx
index 58bfc18767..94360108a1 100644
--- a/packages/react-dev-overlay/src/internal/components/LeftRightDialogHeader/LeftRightDialogHeader.tsx
+++ b/packages/react-dev-overlay/src/internal/components/LeftRightDialogHeader/LeftRightDialogHeader.tsx
@@ -62,7 +62,7 @@ const LeftRightDialogHeader: React.FC<LeftRightDialogHeaderProps> = function Lef
     if (root !== d) {
       d.addEventListener('keydown', handler)
     }
-    return function() {
+    return function () {
       root.removeEventListener('keydown', handler)
       if (root !== d) {
         d.removeEventListener('keydown', handler)
diff --git a/packages/react-dev-overlay/src/internal/container/Errors.tsx b/packages/react-dev-overlay/src/internal/container/Errors.tsx
index 6cdeb26f75..316164d04c 100644
--- a/packages/react-dev-overlay/src/internal/container/Errors.tsx
+++ b/packages/react-dev-overlay/src/internal/container/Errors.tsx
@@ -120,11 +120,11 @@ export const Errors: React.FC<ErrorsProps> = function Errors({ errors }) {
       return
     }
     getErrorByType(nextError).then(
-      resolved => {
+      (resolved) => {
         // We don't care if the desired error changed while we were resolving,
         // thus we're not tracking it using a ref. Once the work has been done,
         // we'll store it.
-        setLookups(m => ({ ...m, [resolved.id]: resolved }))
+        setLookups((m) => ({ ...m, [resolved.id]: resolved }))
       },
       () => {
         // TODO: handle this, though an edge case
@@ -136,12 +136,14 @@ export const Errors: React.FC<ErrorsProps> = function Errors({ errors }) {
   const [activeIdx, setActiveIndex] = React.useState<number>(0)
   const previous = React.useCallback((e?: MouseEvent | TouchEvent) => {
     e?.preventDefault()
-    setActiveIndex(v => Math.max(0, v - 1))
+    setActiveIndex((v) => Math.max(0, v - 1))
   }, [])
   const next = React.useCallback(
     (e?: MouseEvent | TouchEvent) => {
       e?.preventDefault()
-      setActiveIndex(v => Math.max(0, Math.min(readyErrors.length - 1, v + 1)))
+      setActiveIndex((v) =>
+        Math.max(0, Math.min(readyErrors.length - 1, v + 1))
+      )
     },
     [readyErrors.length]
   )
@@ -246,9 +248,7 @@ export const Errors: React.FC<ErrorsProps> = function Errors({ errors }) {
                   logs will be displayed in the terminal window.
                 </small>
               </div>
-            ) : (
-              undefined
-            )}
+            ) : undefined}
           </DialogHeader>
           <DialogBody className="nextjs-container-errors-body">
             <RuntimeError key={activeError.id.toString()} error={activeError} />
diff --git a/packages/react-dev-overlay/src/internal/container/RuntimeError.tsx b/packages/react-dev-overlay/src/internal/container/RuntimeError.tsx
index 6622d8833d..1cb7a92e47 100644
--- a/packages/react-dev-overlay/src/internal/container/RuntimeError.tsx
+++ b/packages/react-dev-overlay/src/internal/container/RuntimeError.tsx
@@ -68,7 +68,7 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
 }) {
   const firstFirstPartyFrameIndex = React.useMemo<number>(() => {
     return error.frames.findIndex(
-      entry =>
+      (entry) =>
         entry.expanded &&
         Boolean(entry.originalCodeFrame) &&
         Boolean(entry.originalStackFrame)
@@ -88,11 +88,11 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
 
   const [all, setAll] = React.useState(firstFrame == null)
   const toggleAll = React.useCallback(() => {
-    setAll(v => !v)
+    setAll((v) => !v)
   }, [])
 
   const leadingFrames = React.useMemo(
-    () => allLeadingFrames.filter(f => f.expanded || all),
+    () => allLeadingFrames.filter((f) => f.expanded || all),
     [all, allLeadingFrames]
   )
   const allCallStackFrames = React.useMemo<OriginalStackFrame[]>(
@@ -100,7 +100,7 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
     [error.frames, firstFirstPartyFrameIndex]
   )
   const visibleCallStackFrames = React.useMemo<OriginalStackFrame[]>(
-    () => allCallStackFrames.filter(f => f.expanded || all),
+    () => allCallStackFrames.filter((f) => f.expanded || all),
     [all, allCallStackFrames]
   )
 
@@ -132,9 +132,7 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
             codeFrame={firstFrame.originalCodeFrame}
           />
         </React.Fragment>
-      ) : (
-        undefined
-      )}
+      ) : undefined}
       {visibleCallStackFrames.length ? (
         <React.Fragment>
           <h5>Call Stack</h5>
@@ -142,9 +140,7 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
             <CallStackFrame key={`call-stack-${index}-${all}`} frame={frame} />
           ))}
         </React.Fragment>
-      ) : (
-        undefined
-      )}
+      ) : undefined}
       {canShowMore ? (
         <React.Fragment>
           <button
@@ -156,9 +152,7 @@ const RuntimeError: React.FC<RuntimeErrorProps> = function RuntimeError({
             {all ? 'Hide' : 'Show'} collapsed frames
           </button>
         </React.Fragment>
-      ) : (
-        undefined
-      )}
+      ) : undefined}
     </React.Fragment>
   )
 }
diff --git a/packages/react-dev-overlay/src/internal/helpers/launchEditor.ts b/packages/react-dev-overlay/src/internal/helpers/launchEditor.ts
index 6c5483e01e..dffc633ed3 100644
--- a/packages/react-dev-overlay/src/internal/helpers/launchEditor.ts
+++ b/packages/react-dev-overlay/src/internal/helpers/launchEditor.ts
@@ -421,12 +421,12 @@ function launchEditor(fileName: string, lineNumber: number, colNumber: number) {
   }
 
   if (p) {
-    p.on('exit', function(errorCode) {
+    p.on('exit', function (errorCode) {
       if (errorCode) {
         printInstructions(fileName, '(code ' + errorCode + ')')
       }
     })
-    p.on('error', function(error) {
+    p.on('error', function (error) {
       printInstructions(fileName, error.message)
     })
   }
diff --git a/packages/react-dev-overlay/src/internal/helpers/nodeStackFrames.ts b/packages/react-dev-overlay/src/internal/helpers/nodeStackFrames.ts
index 903b829b5f..41aeec9209 100644
--- a/packages/react-dev-overlay/src/internal/helpers/nodeStackFrames.ts
+++ b/packages/react-dev-overlay/src/internal/helpers/nodeStackFrames.ts
@@ -37,7 +37,7 @@ export function getNodeError(error: Error): Error {
   try {
     n.stack = parse(error.stack)
       .map(getFilesystemFrame)
-      .map(f => {
+      .map((f) => {
         let str = `    at ${f.methodName}`
         if (f.file) {
           let loc = f.file
diff --git a/packages/react-dev-overlay/src/internal/helpers/parseStack.ts b/packages/react-dev-overlay/src/internal/helpers/parseStack.ts
index cf6cda7598..f329dd6126 100644
--- a/packages/react-dev-overlay/src/internal/helpers/parseStack.ts
+++ b/packages/react-dev-overlay/src/internal/helpers/parseStack.ts
@@ -4,7 +4,7 @@ const regexNextStatic = /\/_next(\/static\/.+)/g
 
 export function parseStack(stack: string): StackFrame[] {
   const frames = parse(stack)
-  return frames.map(frame => {
+  return frames.map((frame) => {
     try {
       const url = new URL(frame.file)
       const res = regexNextStatic.exec(url.pathname)
diff --git a/packages/react-dev-overlay/src/internal/helpers/stack-frame.ts b/packages/react-dev-overlay/src/internal/helpers/stack-frame.ts
index 234463acc7..6a5acbe364 100644
--- a/packages/react-dev-overlay/src/internal/helpers/stack-frame.ts
+++ b/packages/react-dev-overlay/src/internal/helpers/stack-frame.ts
@@ -31,7 +31,7 @@ export type OriginalStackFrame =
     }
 
 export function getOriginalStackFrames(frames: StackFrame[]) {
-  return Promise.all(frames.map(frame => getOriginalStackFrame(frame)))
+  return Promise.all(frames.map((frame) => getOriginalStackFrame(frame)))
 }
 
 export function getOriginalStackFrame(
diff --git a/packages/react-dev-overlay/src/internal/hooks/use-on-click-outside.ts b/packages/react-dev-overlay/src/internal/hooks/use-on-click-outside.ts
index e553ac425f..8c73686882 100644
--- a/packages/react-dev-overlay/src/internal/hooks/use-on-click-outside.ts
+++ b/packages/react-dev-overlay/src/internal/hooks/use-on-click-outside.ts
@@ -21,7 +21,7 @@ export function useOnClickOutside(
     const root = el.getRootNode()
     root.addEventListener('mousedown', listener)
     root.addEventListener('touchstart', listener)
-    return function() {
+    return function () {
       root.removeEventListener('mousedown', listener)
       root.removeEventListener('touchstart', listener)
     }
diff --git a/packages/react-dev-overlay/src/middleware.ts b/packages/react-dev-overlay/src/middleware.ts
index a17f48bcc8..ec44c24e5b 100644
--- a/packages/react-dev-overlay/src/middleware.ts
+++ b/packages/react-dev-overlay/src/middleware.ts
@@ -50,7 +50,7 @@ function getOverlayMiddleware(options: OverlayMiddlewareOptions) {
 
     try {
       const compilation = options.stats()?.compilation
-      const m = compilation?.modules?.find(m => m.id === id)
+      const m = compilation?.modules?.find((m) => m.id === id)
       return (
         m?.source(
           compilation.dependencyTemplates,
@@ -63,7 +63,7 @@ function getOverlayMiddleware(options: OverlayMiddlewareOptions) {
     }
   }
 
-  return async function(
+  return async function (
     req: IncomingMessage,
     res: ServerResponse,
     next: Function
diff --git a/packages/react-refresh-utils/ReactRefreshWebpackPlugin.ts b/packages/react-refresh-utils/ReactRefreshWebpackPlugin.ts
index a0f8a9e517..8c208a90da 100644
--- a/packages/react-refresh-utils/ReactRefreshWebpackPlugin.ts
+++ b/packages/react-refresh-utils/ReactRefreshWebpackPlugin.ts
@@ -7,7 +7,7 @@ function webpack4(compiler: Compiler) {
   // `strictModuleExceptionHandling` in `MainTemplate`:
   // https://github.com/webpack/webpack/blob/4c644bf1f7cb067c748a52614500e0e2182b2700/lib/MainTemplate.js#L200
 
-  compiler.hooks.compilation.tap('ReactFreshWebpackPlugin', compilation => {
+  compiler.hooks.compilation.tap('ReactFreshWebpackPlugin', (compilation) => {
     const hookRequire: typeof compilation['mainTemplate']['hooks']['requireExtensions'] = (compilation
       .mainTemplate.hooks as any).require
 
@@ -19,7 +19,7 @@ function webpack4(compiler: Compiler) {
       // https://github.com/webpack/webpack/blob/4c644bf1f7cb067c748a52614500e0e2182b2700/lib/MainTemplate.js#L200
 
       const lines = source.split('\n')
-      const evalIndex = lines.findIndex(l =>
+      const evalIndex = lines.findIndex((l) =>
         l.includes('modules[moduleId].call(')
       )
       // Unable to find the module execution, that's OK:
diff --git a/packages/react-refresh-utils/internal/ReactRefreshModule.runtime.ts b/packages/react-refresh-utils/internal/ReactRefreshModule.runtime.ts
index 7f1c07ca21..581d65bf67 100644
--- a/packages/react-refresh-utils/internal/ReactRefreshModule.runtime.ts
+++ b/packages/react-refresh-utils/internal/ReactRefreshModule.runtime.ts
@@ -16,7 +16,7 @@ declare const module: {
 
 // This function gets unwrapped into global scope, which is why we don't invert
 // if-blocks. Also, you cannot use `return`.
-export default function() {
+export default function () {
   // Legacy CSS implementations will `eval` browser code in a Node.js context
   // to extract CSS. For backwards compatibility, we need to check we're in a
   // browser context before continuing.
@@ -40,7 +40,7 @@ export default function() {
     if (self.$RefreshHelpers$.isReactRefreshBoundary(currentExports)) {
       // Save the previous exports on update so we can compare the boundary
       // signatures.
-      module.hot.dispose(data => {
+      module.hot.dispose((data) => {
         data.prevExports = currentExports
       })
       // Unconditionally accept an update to this module, we'll check if it's
diff --git a/packages/react-refresh-utils/runtime.ts b/packages/react-refresh-utils/runtime.ts
index 2472985430..5bf0483896 100644
--- a/packages/react-refresh-utils/runtime.ts
+++ b/packages/react-refresh-utils/runtime.ts
@@ -15,13 +15,13 @@ RefreshRuntime.injectIntoGlobalHook(self)
 
 // noop fns to prevent runtime errors during initialization
 self.$RefreshReg$ = () => {}
-self.$RefreshSig$ = () => type => type
+self.$RefreshSig$ = () => (type) => type
 
 // Register global helpers
 self.$RefreshHelpers$ = RefreshHelpers
 
 // Register a helper for module execution interception
-self.$RefreshInterceptModuleExecution$ = function(webpackModuleId) {
+self.$RefreshInterceptModuleExecution$ = function (webpackModuleId) {
   const prevRefreshReg = self.$RefreshReg$
   const prevRefreshSig = self.$RefreshSig$
 
diff --git a/run-tests.js b/run-tests.js
index d8c37dd5ed..df5991493e 100644
--- a/run-tests.js
+++ b/run-tests.js
@@ -27,7 +27,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
   const groupArg = groupIdx !== -1 && process.argv[groupIdx + 1]
 
   console.log('Running tests with concurrency:', concurrency)
-  let tests = process.argv.filter(arg => arg.endsWith('.test.js'))
+  let tests = process.argv.filter((arg) => arg.endsWith('.test.js'))
   let prevTimings
 
   if (tests.length === 0) {
@@ -56,7 +56,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
 
   let testNames = [
     ...new Set(
-      tests.map(f => {
+      tests.map((f) => {
         let name = `${f.replace(/\\/g, '/').replace(/\/test$/, '')}`
         if (!name.startsWith('test/')) name = `test/${name}`
         return name
@@ -109,7 +109,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
       testNames = testNames.splice(offset, numPerGroup)
     }
   }
-  console.log('Running tests:', '\n', ...testNames.map(name => `${name}\n`))
+  console.log('Running tests:', '\n', ...testNames.map((name) => `${name}\n`))
 
   const sema = new Sema(concurrency, { capacity: testNames.length })
   const jestPath = path.join(
@@ -155,7 +155,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
         }
       )
       children.add(child)
-      child.on('exit', code => {
+      child.on('exit', (code) => {
         children.delete(child)
         if (code) reject(new Error(`failed with code: ${code}`))
         resolve(new Date().getTime() - start)
@@ -163,7 +163,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
     })
 
   await Promise.all(
-    testNames.map(async test => {
+    testNames.map(async (test) => {
       await sema.acquire()
       let passed = false
 
@@ -189,7 +189,7 @@ const TIMINGS_API = `https://next-timings.jjsweb.site/api/timings`
       }
       if (!passed) {
         console.error(`${test} failed to pass within ${NUM_RETRIES} retries`)
-        children.forEach(child => child.kill())
+        children.forEach((child) => child.kill())
 
         if (isTestJob) {
           try {
diff --git a/test/acceptance/ReactRefreshLogBox.test.js b/test/acceptance/ReactRefreshLogBox.test.js
index 750d0af13a..bf03aa3734 100644
--- a/test/acceptance/ReactRefreshLogBox.test.js
+++ b/test/acceptance/ReactRefreshLogBox.test.js
@@ -477,7 +477,7 @@ test('syntax > runtime error', async () => {
     `
   )
 
-  await new Promise(resolve => setTimeout(resolve, 1000))
+  await new Promise((resolve) => setTimeout(resolve, 1000))
   expect(await session.hasRedbox(true)).toBe(true)
   if (process.platform === 'win32') {
     expect(await session.getRedboxSource()).toMatchInlineSnapshot(`
@@ -518,7 +518,7 @@ test('syntax > runtime error', async () => {
       export default function FunctionNamed() {`
   )
 
-  await new Promise(resolve => setTimeout(resolve, 1000))
+  await new Promise((resolve) => setTimeout(resolve, 1000))
   expect(await session.hasRedbox(true)).toBe(true)
   expect(await session.getRedboxSource()).toMatchInlineSnapshot(`
     "./index.js:8:47
@@ -531,7 +531,7 @@ test('syntax > runtime error', async () => {
   `)
 
   // Test that runtime error does not take over:
-  await new Promise(resolve => setTimeout(resolve, 2000))
+  await new Promise((resolve) => setTimeout(resolve, 2000))
   expect(await session.hasRedbox(true)).toBe(true)
   expect(await session.getRedboxSource()).toMatchInlineSnapshot(`
     "./index.js:8:47
diff --git a/test/acceptance/helpers.js b/test/acceptance/helpers.js
index e6804aa34c..b6bbb3a268 100644
--- a/test/acceptance/helpers.js
+++ b/test/acceptance/helpers.js
@@ -40,13 +40,13 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
       },
       async patch(fileName, content) {
         // Register an event for HMR completion
-        await browser.executeScript(function() {
+        await browser.executeScript(function () {
           window.__HMR_STATE = 'pending'
 
           var timeout = setTimeout(() => {
             window.__HMR_STATE = 'timeout'
           }, 30 * 1000)
-          window.__NEXT_HMR_CB = function() {
+          window.__NEXT_HMR_CB = function () {
             clearTimeout(timeout)
             window.__HMR_STATE = 'success'
           }
@@ -57,16 +57,16 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
         for (;;) {
           const status = await browser.executeScript(() => window.__HMR_STATE)
           if (!status) {
-            await new Promise(resolve => setTimeout(resolve, 750))
+            await new Promise((resolve) => setTimeout(resolve, 750))
 
             // Wait for application to re-hydrate:
-            await browser.executeAsyncScript(function() {
+            await browser.executeAsyncScript(function () {
               var callback = arguments[arguments.length - 1]
               if (window.__NEXT_HYDRATED) {
                 callback()
               } else {
                 var timeout = setTimeout(callback, 30 * 1000)
-                window.__NEXT_HYDRATED_CB = function() {
+                window.__NEXT_HYDRATED_CB = function () {
                   clearTimeout(timeout)
                   callback()
                 }
@@ -75,7 +75,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
 
             console.log('Application re-loaded.')
             // Slow down tests a bit:
-            await new Promise(resolve => setTimeout(resolve, 750))
+            await new Promise((resolve) => setTimeout(resolve, 750))
             return false
           }
           if (status === 'success') {
@@ -86,11 +86,11 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
             throw new Error(`Application is in inconsistent state: ${status}.`)
           }
 
-          await new Promise(resolve => setTimeout(resolve, 30))
+          await new Promise((resolve) => setTimeout(resolve, 30))
         }
 
         // Slow down tests a bit (we don't know how long re-rendering takes):
-        await new Promise(resolve => setTimeout(resolve, 750))
+        await new Promise((resolve) => setTimeout(resolve, 750))
         return true
       },
       async remove(fileName) {
@@ -101,7 +101,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
         const input = arguments[0]
         if (typeof input === 'function') {
           const result = await browser.executeScript(input)
-          await new Promise(resolve => setTimeout(resolve, 30))
+          await new Promise((resolve) => setTimeout(resolve, 30))
           return result
         } else {
           throw new Error(
@@ -116,7 +116,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
             return Boolean(
               [].slice
                 .call(document.querySelectorAll('nextjs-portal'))
-                .find(p =>
+                .find((p) =>
                   p.shadowRoot.querySelector(
                     '#nextjs__container_errors_label, #nextjs__container_build_error_label'
                   )
@@ -130,7 +130,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
             break
           }
 
-          await new Promise(resolve => setTimeout(resolve, 1000))
+          await new Promise((resolve) => setTimeout(resolve, 1000))
         } while (expected)
         return false
       },
@@ -139,7 +139,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
           ? await this.evaluate(() => {
               const portal = [].slice
                 .call(document.querySelectorAll('nextjs-portal'))
-                .find(p =>
+                .find((p) =>
                   p.shadowRoot.querySelector('[data-nextjs-dialog-header')
                 )
               const root = portal.shadowRoot
@@ -150,7 +150,7 @@ export async function sandbox(id = nanoid(), initialFiles = new Map()) {
         const source = await this.evaluate(() => {
           const portal = [].slice
             .call(document.querySelectorAll('nextjs-portal'))
-            .find(p =>
+            .find((p) =>
               p.shadowRoot.querySelector(
                 '#nextjs__container_errors_label, #nextjs__container_build_error_label'
               )
diff --git a/test/integration/404-page-custom-error/test/index.test.js b/test/integration/404-page-custom-error/test/index.test.js
index 033ff09a1a..09b91b25d5 100644
--- a/test/integration/404-page-custom-error/test/index.test.js
+++ b/test/integration/404-page-custom-error/test/index.test.js
@@ -21,7 +21,7 @@ let appPort
 let buildId
 let app
 
-const runTests = mode => {
+const runTests = (mode) => {
   const isDev = mode === 'dev'
 
   it('should respond to 404 correctly', async () => {
diff --git a/test/integration/404-page-ssg/test/index.test.js b/test/integration/404-page-ssg/test/index.test.js
index 30739241bf..a9573cd44b 100644
--- a/test/integration/404-page-ssg/test/index.test.js
+++ b/test/integration/404-page-ssg/test/index.test.js
@@ -25,7 +25,7 @@ let buildId
 let appPort
 let app
 
-const runTests = isDev => {
+const runTests = (isDev) => {
   it('should respond to 404 correctly', async () => {
     const res = await fetchViaHTTP(appPort, '/404')
     expect(res.status).toBe(404)
diff --git a/test/integration/amp-export-validation/test/index.test.js b/test/integration/amp-export-validation/test/index.test.js
index 1cda753bb0..012356abae 100644
--- a/test/integration/amp-export-validation/test/index.test.js
+++ b/test/integration/amp-export-validation/test/index.test.js
@@ -35,7 +35,7 @@ describe('AMP Validation on Export', () => {
   it('should export AMP pages', async () => {
     const toCheck = ['first', 'second', 'third.amp']
     await Promise.all(
-      toCheck.map(async page => {
+      toCheck.map(async (page) => {
         const content = await readFile(join(outDir, `${page}.html`))
         await validateAMP(content.toString())
       })
diff --git a/test/integration/amphtml-custom-optimizer/pages/dynamic.js b/test/integration/amphtml-custom-optimizer/pages/dynamic.js
index ed59c6f760..2cdfea262e 100644
--- a/test/integration/amphtml-custom-optimizer/pages/dynamic.js
+++ b/test/integration/amphtml-custom-optimizer/pages/dynamic.js
@@ -2,7 +2,7 @@ export const config = {
   amp: true,
 }
 
-const Dynamic = props => (
+const Dynamic = (props) => (
   <amp-img
     width="500"
     height="500"
diff --git a/test/integration/amphtml-ssg/test/index.test.js b/test/integration/amphtml-ssg/test/index.test.js
index 7e22f70d0a..0e1f6c4010 100644
--- a/test/integration/amphtml-ssg/test/index.test.js
+++ b/test/integration/amphtml-ssg/test/index.test.js
@@ -22,7 +22,7 @@ let app
 
 jest.setTimeout(1000 * 60 * 2)
 
-const fsExists = file =>
+const fsExists = (file) =>
   fs
     .access(file)
     .then(() => true)
@@ -58,7 +58,7 @@ const runTests = (isDev = false) => {
   })
 
   if (!isDev) {
-    const builtPage = file => join(builtServerPagesDir, file)
+    const builtPage = (file) => join(builtServerPagesDir, file)
 
     it('should output prerendered files correctly during build', async () => {
       expect(await fsExists(builtPage('amp.js'))).toBe(true)
@@ -132,7 +132,7 @@ describe('AMP SSG Support', () => {
     })
 
     it('should have copied SSG files correctly', async () => {
-      const outFile = file => join(appDir, 'out', file)
+      const outFile = (file) => join(appDir, 'out', file)
 
       expect(await fsExists(outFile('amp.html'))).toBe(true)
       expect(await fsExists(outFile('index.html'))).toBe(true)
diff --git a/test/integration/amphtml/test/index.test.js b/test/integration/amphtml/test/index.test.js
index a1d32b9305..fe9bdfa154 100644
--- a/test/integration/amphtml/test/index.test.js
+++ b/test/integration/amphtml/test/index.test.js
@@ -108,7 +108,7 @@ describe('AMP Usage', () => {
             $('link[rel=preload]')
               .toArray()
               .find(
-                i => $(i).attr('href') === 'https://cdn.ampproject.org/v0.js'
+                (i) => $(i).attr('href') === 'https://cdn.ampproject.org/v0.js'
               )
           ).attr('href')
         ).toBe('https://cdn.ampproject.org/v0.js')
@@ -166,11 +166,9 @@ describe('AMP Usage', () => {
       it('should render link rel amphtml', async () => {
         const html = await renderViaHTTP(appPort, '/use-amp-hook')
         const $ = cheerio.load(html)
-        expect(
-          $('link[rel=amphtml]')
-            .first()
-            .attr('href')
-        ).toBe('http://localhost:1234/use-amp-hook.amp')
+        expect($('link[rel=amphtml]').first().attr('href')).toBe(
+          'http://localhost:1234/use-amp-hook.amp'
+        )
       })
 
       it('should render amphtml from provided rel link', async () => {
@@ -187,32 +185,24 @@ describe('AMP Usage', () => {
         const html = await renderViaHTTP(appPort, '/use-amp-hook?amp=1')
         const $ = cheerio.load(html)
         await validateAMP(html)
-        expect(
-          $('link[rel=canonical]')
-            .first()
-            .attr('href')
-        ).toBe('http://localhost:1234/use-amp-hook')
+        expect($('link[rel=canonical]').first().attr('href')).toBe(
+          'http://localhost:1234/use-amp-hook'
+        )
       })
 
       it('should render a canonical regardless of amp-only status (explicit)', async () => {
         const html = await renderViaHTTP(appPort, '/only-amp')
         const $ = cheerio.load(html)
         await validateAMP(html)
-        expect(
-          $('link[rel=canonical]')
-            .first()
-            .attr('href')
-        ).toBe('http://localhost:1234/only-amp')
+        expect($('link[rel=canonical]').first().attr('href')).toBe(
+          'http://localhost:1234/only-amp'
+        )
       })
 
       it('should not render amphtml link tag with no AMP page', async () => {
         const html = await renderViaHTTP(appPort, '/normal')
         const $ = cheerio.load(html)
-        expect(
-          $('link[rel=amphtml]')
-            .first()
-            .attr('href')
-        ).not.toBeTruthy()
+        expect($('link[rel=amphtml]').first().attr('href')).not.toBeTruthy()
       })
 
       it('should remove conflicting amp tags', async () => {
@@ -245,11 +235,7 @@ describe('AMP Usage', () => {
       it('should combine style tags', async () => {
         const html = await renderViaHTTP(appPort, '/styled?amp=1')
         const $ = cheerio.load(html)
-        expect(
-          $('style[amp-custom]')
-            .first()
-            .text()
-        ).toMatch(
+        expect($('style[amp-custom]').first().text()).toMatch(
           /div.jsx-\d+{color:red}span.jsx-\d+{color:#00f}body{background-color:green}/
         )
       })
@@ -257,9 +243,7 @@ describe('AMP Usage', () => {
       it('should remove sourceMaps from styles', async () => {
         const html = await renderViaHTTP(appPort, '/styled?amp=1')
         const $ = cheerio.load(html)
-        const styles = $('style[amp-custom]')
-          .first()
-          .text()
+        const styles = $('style[amp-custom]').first().text()
 
         expect(styles).not.toMatch(/\/\*@ sourceURL=.*?\*\//)
         expect(styles).not.toMatch(/\/\*# sourceMappingURL=.*\*\//)
diff --git a/test/integration/api-support/pages/api/child-process.js b/test/integration/api-support/pages/api/child-process.js
index 1b8d1a4d66..9b9a7d92bf 100644
--- a/test/integration/api-support/pages/api/child-process.js
+++ b/test/integration/api-support/pages/api/child-process.js
@@ -1,8 +1,6 @@
 import { execSync } from 'child_process'
 
 export default (req, res) => {
-  const output = execSync('echo hi')
-    .toString()
-    .trim()
+  const output = execSync('echo hi').toString().trim()
   res.end(output)
 }
diff --git a/test/integration/api-support/pages/api/cors.js b/test/integration/api-support/pages/api/cors.js
index 11e09a750d..69752f5d97 100644
--- a/test/integration/api-support/pages/api/cors.js
+++ b/test/integration/api-support/pages/api/cors.js
@@ -5,7 +5,7 @@ import Cors from 'cors'
 function initMiddleware(middleware) {
   return (req, res) =>
     new Promise((resolve, reject) => {
-      middleware(req, res, result => {
+      middleware(req, res, (result) => {
         if (result instanceof Error) {
           return reject(result)
         }
diff --git a/test/integration/api-support/pages/api/external-resolver-false-positive.js b/test/integration/api-support/pages/api/external-resolver-false-positive.js
index 7ee28b508c..1673d668e4 100644
--- a/test/integration/api-support/pages/api/external-resolver-false-positive.js
+++ b/test/integration/api-support/pages/api/external-resolver-false-positive.js
@@ -1,5 +1,5 @@
-export default (_req, res) => {
-  setTimeout(() => {
-    res.send('hello world')
-  }, 0)
-}
+export default (_req, res) => {
+  setTimeout(() => {
+    res.send('hello world')
+  }, 0)
+}
diff --git a/test/integration/api-support/pages/api/external-resolver.js b/test/integration/api-support/pages/api/external-resolver.js
index ea1dea8e05..8023e34e7e 100644
--- a/test/integration/api-support/pages/api/external-resolver.js
+++ b/test/integration/api-support/pages/api/external-resolver.js
@@ -1,11 +1,11 @@
-export default (_req, res) => {
-  setTimeout(() => {
-    res.send('hello world')
-  }, 0)
-}
-
-export const config = {
-  api: {
-    externalResolver: true,
-  },
-}
+export default (_req, res) => {
+  setTimeout(() => {
+    res.send('hello world')
+  }, 0)
+}
+
+export const config = {
+  api: {
+    externalResolver: true,
+  },
+}
diff --git a/test/integration/api-support/pages/api/no-parsing.js b/test/integration/api-support/pages/api/no-parsing.js
index c97647e000..4b361a9fd0 100644
--- a/test/integration/api-support/pages/api/no-parsing.js
+++ b/test/integration/api-support/pages/api/no-parsing.js
@@ -5,10 +5,10 @@ export const config = {
 }
 
 export default (req, res) => {
-  return new Promise(resolve => {
+  return new Promise((resolve) => {
     if (!req.body) {
       let buffer = ''
-      req.on('data', chunk => {
+      req.on('data', (chunk) => {
         buffer += chunk
       })
 
diff --git a/test/integration/api-support/pages/api/users.js b/test/integration/api-support/pages/api/users.js
index 7ca0021e06..60128c8616 100644
--- a/test/integration/api-support/pages/api/users.js
+++ b/test/integration/api-support/pages/api/users.js
@@ -2,7 +2,7 @@ export default ({ query }, res) => {
   const users = [{ name: 'Tim' }, { name: 'Jon' }]
 
   const response = query.name
-    ? users.filter(user => user.name === query.name)
+    ? users.filter((user) => user.name === query.name)
     : users
 
   res.status(200).json(response)
diff --git a/test/integration/api-support/test/index.test.js b/test/integration/api-support/test/index.test.js
index b7e2f7db0e..9b09e117dc 100644
--- a/test/integration/api-support/test/index.test.js
+++ b/test/integration/api-support/test/index.test.js
@@ -60,7 +60,7 @@ function runTests(dev = false) {
 
   it('should work with index api', async () => {
     const text = await fetchViaHTTP(appPort, '/api', null, {}).then(
-      res => res.ok && res.text()
+      (res) => res.ok && res.text()
     )
     expect(text).toEqual('Index should work')
   })
@@ -94,7 +94,7 @@ function runTests(dev = false) {
         'Content-Type': 'application/json; charset=utf-8',
       },
       body: JSON.stringify([{ title: 'Nextjs' }]),
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual([{ title: 'Nextjs' }])
   })
@@ -105,7 +105,7 @@ function runTests(dev = false) {
       headers: {
         'Content-Type': 'application/json; charset=utf-8',
       },
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual({})
   })
@@ -180,7 +180,7 @@ function runTests(dev = false) {
     }
 
     const formBody = Object.keys(body)
-      .map(key => {
+      .map((key) => {
         return `${encodeURIComponent(key)}=${encodeURIComponent(body[key])}`
       })
       .join('&')
@@ -191,7 +191,7 @@ function runTests(dev = false) {
         'Content-Type': 'application/x-www-Form-urlencoded',
       },
       body: formBody,
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual({
       title: 'Nextjs',
@@ -206,7 +206,7 @@ function runTests(dev = false) {
         'Content-Type': 'application/json; charset=utf-8',
       },
       body: JSON.stringify([{ title: 'Nextjs' }]),
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual([{ title: 'Nextjs' }])
   })
@@ -218,14 +218,14 @@ function runTests(dev = false) {
         'Content-Type': 'application/json; charset=utf-8',
       },
       body: JSON.stringify([{ title: 'Nextjs' }]),
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual({ message: 'Parsed body' })
   })
 
   it('should return empty query object', async () => {
     const data = await fetchViaHTTP(appPort, '/api/query', null, {}).then(
-      res => res.ok && res.json()
+      (res) => res.ok && res.json()
     )
     expect(data).toEqual({})
   })
@@ -236,13 +236,13 @@ function runTests(dev = false) {
       '/api/query?a=1&b=2&a=3',
       null,
       {}
-    ).then(res => res.ok && res.json())
+    ).then((res) => res.ok && res.json())
     expect(data).toEqual({ a: ['1', '3'], b: '2' })
   })
 
   it('should return empty cookies object', async () => {
     const data = await fetchViaHTTP(appPort, '/api/cookies', null, {}).then(
-      res => res.ok && res.json()
+      (res) => res.ok && res.json()
     )
     expect(data).toEqual({})
   })
@@ -252,7 +252,7 @@ function runTests(dev = false) {
       headers: {
         Cookie: 'nextjs=cool;',
       },
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
     expect(data).toEqual({ nextjs: 'cool' })
   })
 
@@ -267,14 +267,14 @@ function runTests(dev = false) {
   it('should return JSON on post on API', async () => {
     const data = await fetchViaHTTP(appPort, '/api/blog?title=Nextjs', null, {
       method: 'POST',
-    }).then(res => res.ok && res.json())
+    }).then((res) => res.ok && res.json())
 
     expect(data).toEqual([{ title: 'Nextjs' }])
   })
 
   it('should return data on dynamic route', async () => {
     const data = await fetchViaHTTP(appPort, '/api/post-1', null, {}).then(
-      res => res.ok && res.json()
+      (res) => res.ok && res.json()
     )
 
     expect(data).toEqual({ post: 'post-1' })
@@ -286,7 +286,7 @@ function runTests(dev = false) {
       '/api/post-1?val=1',
       null,
       {}
-    ).then(res => res.ok && res.json())
+    ).then((res) => res.ok && res.json())
 
     expect(data).toEqual({ val: '1', post: 'post-1' })
   })
@@ -304,7 +304,7 @@ function runTests(dev = false) {
       '/api/post-1/comments',
       null,
       {}
-    ).then(res => res.ok && res.json())
+    ).then((res) => res.ok && res.json())
 
     expect(data).toEqual([{ message: 'Prioritize a non-dynamic api page' }])
   })
@@ -315,7 +315,7 @@ function runTests(dev = false) {
       '/api/post-1/comment-1',
       null,
       {}
-    ).then(res => res.ok && res.json())
+    ).then((res) => res.ok && res.json())
 
     expect(data).toEqual({ post: 'post-1', comment: 'comment-1' })
   })
@@ -332,7 +332,7 @@ function runTests(dev = false) {
       '/api/blog/post-1/comment/1',
       null,
       {}
-    ).then(res => res.ok && res.json())
+    ).then((res) => res.ok && res.json())
 
     expect(data).toEqual({ post: 'post-1', id: '1' })
   })
@@ -452,7 +452,7 @@ describe('API routes', () => {
       stderr = ''
       appPort = await findPort()
       app = await launchApp(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
diff --git a/test/integration/app-aspath/pages/index.js b/test/integration/app-aspath/pages/index.js
index 49e5509c50..4d7d93f968 100644
--- a/test/integration/app-aspath/pages/index.js
+++ b/test/integration/app-aspath/pages/index.js
@@ -1 +1 @@
-export default props => JSON.stringify(props, null, 2)
+export default (props) => JSON.stringify(props, null, 2)
diff --git a/test/integration/app-document-import-order/sideEffectModule.js b/test/integration/app-document-import-order/sideEffectModule.js
index e8df3b7e97..378e2b3909 100644
--- a/test/integration/app-document-import-order/sideEffectModule.js
+++ b/test/integration/app-document-import-order/sideEffectModule.js
@@ -1,4 +1,4 @@
-const sideEffect = arg => {
+const sideEffect = (arg) => {
   if (!sideEffect.callArguments) {
     sideEffect.callArguments = []
   }
diff --git a/test/integration/app-document-import-order/test/index.test.js b/test/integration/app-document-import-order/test/index.test.js
index 3b37bc1fd6..0876420e7d 100644
--- a/test/integration/app-document-import-order/test/index.test.js
+++ b/test/integration/app-document-import-order/test/index.test.js
@@ -60,12 +60,12 @@ describe('Root components import order', () => {
     const requiredByRegex = /^\/_next\/static\/chunks\/(requiredBy\w*).*\.js/
     const chunks = Array.from($('head').contents())
       .filter(
-        child =>
+        (child) =>
           child.type === 'tag' &&
           child.name === 'link' &&
           child.attribs.href.match(requiredByRegex)
       )
-      .map(child => child.attribs.href.match(requiredByRegex)[1])
+      .map((child) => child.attribs.href.match(requiredByRegex)[1])
 
     const requiredByAppIndex = chunks.indexOf('requiredByApp')
     const requiredByPageIndex = chunks.indexOf('requiredByPage')
diff --git a/test/integration/app-document/pages/_document.js b/test/integration/app-document/pages/_document.js
index e96fbf366f..72ac155974 100644
--- a/test/integration/app-document/pages/_document.js
+++ b/test/integration/app-document/pages/_document.js
@@ -1,7 +1,7 @@
 import crypto from 'crypto'
 import Document, { Html, Head, Main, NextScript } from 'next/document'
 
-const cspHashOf = text => {
+const cspHashOf = (text) => {
   const hash = crypto.createHash('sha256')
   hash.update(text)
   return `'sha256-${hash.digest('base64')}'`
@@ -11,13 +11,13 @@ export default class MyDocument extends Document {
   static async getInitialProps(ctx) {
     let options
 
-    const enhanceComponent = Component => props => (
+    const enhanceComponent = (Component) => (props) => (
       <div>
         <span id="render-page-enhance-component">RENDERED</span>
         <Component {...props} />
       </div>
     )
-    const enhanceApp = Component => props => (
+    const enhanceApp = (Component) => (props) => (
       <div>
         <span id="render-page-enhance-app">RENDERED</span>
         <Component {...props} />
diff --git a/test/integration/app-document/test/csp.js b/test/integration/app-document/test/csp.js
index 390201e70d..268b48acaa 100644
--- a/test/integration/app-document/test/csp.js
+++ b/test/integration/app-document/test/csp.js
@@ -7,7 +7,7 @@ export default (context, render) => {
       const browser = await webdriver(context.appPort, '/?withCSP=hash')
       if (global.browserName === 'chrome') {
         const errLog = await browser.log('browser')
-        expect(errLog.filter(e => e.source === 'security')).toEqual([])
+        expect(errLog.filter((e) => e.source === 'security')).toEqual([])
       }
       await browser.close()
     })
@@ -16,7 +16,7 @@ export default (context, render) => {
       const browser = await webdriver(context.appPort, '/?withCSP=nonce')
       if (global.browserName === 'chrome') {
         const errLog = await browser.log('browser')
-        expect(errLog.filter(e => e.source === 'security')).toEqual([])
+        expect(errLog.filter((e) => e.source === 'security')).toEqual([])
       }
       await browser.close()
     })
diff --git a/test/integration/app-document/test/index.test.js b/test/integration/app-document/test/index.test.js
index 2cff442258..a5d0d34f6d 100644
--- a/test/integration/app-document/test/index.test.js
+++ b/test/integration/app-document/test/index.test.js
@@ -19,7 +19,7 @@ const context = {
 }
 jest.setTimeout(1000 * 60 * 5)
 
-const collectOutput = message => {
+const collectOutput = (message) => {
   context.output += message
 }
 
diff --git a/test/integration/app-document/test/rendering.js b/test/integration/app-document/test/rendering.js
index 2b0cbb8c2e..2f7eab040b 100644
--- a/test/integration/app-document/test/rendering.js
+++ b/test/integration/app-document/test/rendering.js
@@ -4,7 +4,7 @@ import { join } from 'path'
 import cheerio from 'cheerio'
 import { check, File, waitFor } from 'next-test-utils'
 
-export default function({ app }, suiteName, render, fetch) {
+export default function ({ app }, suiteName, render, fetch) {
   async function get$(path, query) {
     const html = await render(path, query)
     return cheerio.load(html)
@@ -53,46 +53,32 @@ export default function({ app }, suiteName, render, fetch) {
       test('It renders ctx.renderPage with enhancer correctly', async () => {
         const $ = await get$('/?withEnhancer=true')
         const nonce = 'RENDERED'
-        expect(
-          $('#render-page-enhance-component')
-            .text()
-            .includes(nonce)
-        ).toBe(true)
+        expect($('#render-page-enhance-component').text().includes(nonce)).toBe(
+          true
+        )
       })
 
       test('It renders ctx.renderPage with enhanceComponent correctly', async () => {
         const $ = await get$('/?withEnhanceComponent=true')
         const nonce = 'RENDERED'
-        expect(
-          $('#render-page-enhance-component')
-            .text()
-            .includes(nonce)
-        ).toBe(true)
+        expect($('#render-page-enhance-component').text().includes(nonce)).toBe(
+          true
+        )
       })
 
       test('It renders ctx.renderPage with enhanceApp correctly', async () => {
         const $ = await get$('/?withEnhanceApp=true')
         const nonce = 'RENDERED'
-        expect(
-          $('#render-page-enhance-app')
-            .text()
-            .includes(nonce)
-        ).toBe(true)
+        expect($('#render-page-enhance-app').text().includes(nonce)).toBe(true)
       })
 
       test('It renders ctx.renderPage with enhanceApp and enhanceComponent correctly', async () => {
         const $ = await get$('/?withEnhanceComponent=true&withEnhanceApp=true')
         const nonce = 'RENDERED'
-        expect(
-          $('#render-page-enhance-app')
-            .text()
-            .includes(nonce)
-        ).toBe(true)
-        expect(
-          $('#render-page-enhance-component')
-            .text()
-            .includes(nonce)
-        ).toBe(true)
+        expect($('#render-page-enhance-app').text().includes(nonce)).toBe(true)
+        expect($('#render-page-enhance-component').text().includes(nonce)).toBe(
+          true
+        )
       })
 
       // This is a workaround to fix https://github.com/zeit/next.js/issues/5860
diff --git a/test/integration/app-functional/test/index.test.js b/test/integration/app-functional/test/index.test.js
index 80ebc65d4e..f152084de1 100644
--- a/test/integration/app-functional/test/index.test.js
+++ b/test/integration/app-functional/test/index.test.js
@@ -8,7 +8,7 @@ const context = {
 }
 jest.setTimeout(1000 * 60 * 5)
 
-const collectOutput = message => {
+const collectOutput = (message) => {
   context.output += message
 }
 
diff --git a/test/integration/auto-export/pages/[post]/[cmnt].js b/test/integration/auto-export/pages/[post]/[cmnt].js
index d85fada774..6c7af1c61c 100644
--- a/test/integration/auto-export/pages/[post]/[cmnt].js
+++ b/test/integration/auto-export/pages/[post]/[cmnt].js
@@ -4,11 +4,11 @@ if (typeof window !== 'undefined') {
   window.caughtWarns = []
   const origWarn = window.console.warn
   const origError = window.console.error
-  window.console.warn = function(...args) {
+  window.console.warn = function (...args) {
     window.caughtWarns.push(1)
     origWarn(...args)
   }
-  window.console.error = function(...args) {
+  window.console.error = function (...args) {
     window.caughtWarns.push(1)
     origError(...args)
   }
diff --git a/test/integration/auto-export/pages/commonjs1.js b/test/integration/auto-export/pages/commonjs1.js
index 99ac20eac0..cb3b23f0be 100644
--- a/test/integration/auto-export/pages/commonjs1.js
+++ b/test/integration/auto-export/pages/commonjs1.js
@@ -1,6 +1,6 @@
 const React = require('react')
 
-module.exports = function() {
+module.exports = function () {
   return (
     <div>
       <h1>test1</h1>
diff --git a/test/integration/babel/test/rendering.js b/test/integration/babel/test/rendering.js
index e3e1cd53bc..dd3c253dbe 100644
--- a/test/integration/babel/test/rendering.js
+++ b/test/integration/babel/test/rendering.js
@@ -2,7 +2,7 @@
 
 import cheerio from 'cheerio'
 
-export default function({ app }, suiteName, render, fetch) {
+export default function ({ app }, suiteName, render, fetch) {
   async function get$(path, query) {
     const html = await render(path, query)
     return cheerio.load(html)
diff --git a/test/integration/basepath/pages/gsp.js b/test/integration/basepath/pages/gsp.js
index 0270db9326..9fa6a9ad4e 100644
--- a/test/integration/basepath/pages/gsp.js
+++ b/test/integration/basepath/pages/gsp.js
@@ -7,7 +7,7 @@ export const getStaticProps = () => {
   }
 }
 
-export default props => (
+export default (props) => (
   <>
     <h3 id="gsp">getStaticProps</h3>
     <p id="props">{JSON.stringify(props)}</p>
diff --git a/test/integration/basepath/pages/gssp.js b/test/integration/basepath/pages/gssp.js
index be8c1c1f3f..f768667792 100644
--- a/test/integration/basepath/pages/gssp.js
+++ b/test/integration/basepath/pages/gssp.js
@@ -7,7 +7,7 @@ export const getServerSideProps = () => {
   }
 }
 
-export default props => (
+export default (props) => (
   <>
     <h3 id="gssp">getServerSideProps</h3>
     <p id="props">{JSON.stringify(props)}</p>
diff --git a/test/integration/basic/pages/dynamic/bundle.js b/test/integration/basic/pages/dynamic/bundle.js
index 611b52207b..81750ce977 100644
--- a/test/integration/basic/pages/dynamic/bundle.js
+++ b/test/integration/basic/pages/dynamic/bundle.js
@@ -4,7 +4,7 @@ import Router from 'next/router'
 import PropTypes from 'prop-types'
 
 const HelloBundle = dynamic({
-  modules: props => {
+  modules: (props) => {
     const components = {
       HelloContext: import('../../components/hello-context'),
       Hello1: import('../../components/hello1'),
diff --git a/test/integration/basic/test/development-logs.js b/test/integration/basic/test/development-logs.js
index 323c1ca23c..4d255e52bb 100644
--- a/test/integration/basic/test/development-logs.js
+++ b/test/integration/basic/test/development-logs.js
@@ -1,7 +1,7 @@
 /* eslint-env jest */
 import webdriver from 'next-webdriver'
 
-export default context => {
+export default (context) => {
   describe('Development Logs', () => {
     it('should warn when prefetch is true', async () => {
       let browser
@@ -9,7 +9,7 @@ export default context => {
         browser = await webdriver(context.appPort, '/development-logs')
         const browserLogs = await browser.log('browser')
         let foundLog = false
-        browserLogs.forEach(log => {
+        browserLogs.forEach((log) => {
           if (log.message.includes('Next.js auto-prefetches automatically')) {
             foundLog = true
           }
@@ -30,7 +30,7 @@ export default context => {
         )
         const browserLogs = await browser.log('browser')
         let found = false
-        browserLogs.forEach(log => {
+        browserLogs.forEach((log) => {
           if (log.message.includes('Next.js auto-prefetches automatically')) {
             found = true
           }
@@ -51,7 +51,7 @@ export default context => {
         )
         const browserLogs = await browser.log('browser')
         let found = false
-        browserLogs.forEach(log => {
+        browserLogs.forEach((log) => {
           if (log.message.includes('Next.js auto-prefetches automatically')) {
             found = true
           }
diff --git a/test/integration/basic/test/dynamic.js b/test/integration/basic/test/dynamic.js
index 90c2960310..ef2684b07b 100644
--- a/test/integration/basic/test/dynamic.js
+++ b/test/integration/basic/test/dynamic.js
@@ -61,7 +61,7 @@ export default (context, render) => {
           if (global.browserName === 'chrome') {
             const logs = await browser.log('browser')
 
-            logs.forEach(logItem => {
+            logs.forEach((logItem) => {
               expect(logItem.message).not.toMatch(
                 /Expected server HTML to contain/
               )
diff --git a/test/integration/basic/test/process-env.js b/test/integration/basic/test/process-env.js
index 773b450a4e..81d07da4f4 100644
--- a/test/integration/basic/test/process-env.js
+++ b/test/integration/basic/test/process-env.js
@@ -1,7 +1,7 @@
 /* eslint-env jest */
 import webdriver from 'next-webdriver'
 
-export default context => {
+export default (context) => {
   describe('process.env', () => {
     it('should set process.env.NODE_ENV in development', async () => {
       const browser = await webdriver(context.appPort, '/process-env')
diff --git a/test/integration/basic/test/public-folder.js b/test/integration/basic/test/public-folder.js
index e64592e3bc..d070530277 100644
--- a/test/integration/basic/test/public-folder.js
+++ b/test/integration/basic/test/public-folder.js
@@ -1,7 +1,7 @@
 /* eslint-env jest */
 import { renderViaHTTP } from 'next-test-utils'
 
-export default context => {
+export default (context) => {
   describe('Public folder', () => {
     it('should allow access to public files', async () => {
       const data = await renderViaHTTP(context.appPort, '/data/data.txt')
diff --git a/test/integration/basic/test/security.js b/test/integration/basic/test/security.js
index b22b6aebc6..d6cbe4de60 100644
--- a/test/integration/basic/test/security.js
+++ b/test/integration/basic/test/security.js
@@ -1,7 +1,7 @@
 /* eslint-env jest */
 import { fetchViaHTTP } from 'next-test-utils'
 
-module.exports = context => {
+module.exports = (context) => {
   describe('With Security Related Issues', () => {
     it('should not allow accessing files outside .next/static and .next/server directory', async () => {
       const pathsToCheck = [
diff --git a/test/integration/basic/warning-loader.js b/test/integration/basic/warning-loader.js
index 61f784c322..e2ddead12a 100644
--- a/test/integration/basic/warning-loader.js
+++ b/test/integration/basic/warning-loader.js
@@ -1,4 +1,4 @@
-module.exports = function(source) {
+module.exports = function (source) {
   this.emitWarning(
     new Error('This is an expected warning added by warning-loader.js')
   )
diff --git a/test/integration/bigint/test/index.test.js b/test/integration/bigint/test/index.test.js
index 808e9fde3d..08929defa2 100644
--- a/test/integration/bigint/test/index.test.js
+++ b/test/integration/bigint/test/index.test.js
@@ -29,7 +29,7 @@ const runTests = () => {
   it('should return the BigInt result text', async () => {
     const resText = await fetchViaHTTP(appPort, '/api/bigint', null, {
       method: 'GET',
-    }).then(res => res.ok && res.text())
+    }).then((res) => res.ok && res.text())
     expect(resText).toEqual('3')
   })
 }
diff --git a/test/integration/build-indicator/test/index.test.js b/test/integration/build-indicator/test/index.test.js
index 351b94fad7..3320280abd 100644
--- a/test/integration/build-indicator/test/index.test.js
+++ b/test/integration/build-indicator/test/index.test.js
@@ -11,7 +11,7 @@ const nextConfig = join(appDir, 'next.config.js')
 let appPort
 let app
 
-const installCheckVisible = browser => {
+const installCheckVisible = (browser) => {
   return browser.eval(`(function() {
     window.checkInterval = setInterval(function() {
       let watcherDiv = document.querySelector('#__next-build-watcher')
diff --git a/test/integration/build-output/fixtures/basic-app/pages/index.js b/test/integration/build-output/fixtures/basic-app/pages/index.js
index 7d156616c1..3b1ad2208a 100644
--- a/test/integration/build-output/fixtures/basic-app/pages/index.js
+++ b/test/integration/build-output/fixtures/basic-app/pages/index.js
@@ -1,4 +1,4 @@
 /*! DO NOT EXTRACT ME */
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/build-output/fixtures/with-amp/pages/index.js b/test/integration/build-output/fixtures/with-amp/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/build-output/fixtures/with-amp/pages/index.js
+++ b/test/integration/build-output/fixtures/with-amp/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/build-output/fixtures/with-app/pages/index.js b/test/integration/build-output/fixtures/with-app/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/build-output/fixtures/with-app/pages/index.js
+++ b/test/integration/build-output/fixtures/with-app/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/build-output/fixtures/with-error-static/pages/index.js b/test/integration/build-output/fixtures/with-error-static/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/build-output/fixtures/with-error-static/pages/index.js
+++ b/test/integration/build-output/fixtures/with-error-static/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/build-output/fixtures/with-error/pages/index.js b/test/integration/build-output/fixtures/with-error/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/build-output/fixtures/with-error/pages/index.js
+++ b/test/integration/build-output/fixtures/with-error/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/build-warnings/next.config.js b/test/integration/build-warnings/next.config.js
index aecf69fc81..91f7f19c2a 100644
--- a/test/integration/build-warnings/next.config.js
+++ b/test/integration/build-warnings/next.config.js
@@ -1,5 +1,5 @@
 module.exports = {
-  webpack: config => {
+  webpack: (config) => {
     config.optimization.minimize = true
     return config
   },
diff --git a/test/integration/chunking/pages/page3.js b/test/integration/chunking/pages/page3.js
index 91ce805416..03d534597c 100644
--- a/test/integration/chunking/pages/page3.js
+++ b/test/integration/chunking/pages/page3.js
@@ -1,5 +1,5 @@
 import Link from 'next/link'
-import('lodash').then(_ => console.log(_.chunk(['a', 'b', 'c', 'd'], 2)))
+import('lodash').then((_) => console.log(_.chunk(['a', 'b', 'c', 'd'], 2)))
 
 const Page = () => {
   return (
diff --git a/test/integration/chunking/test/index.test.js b/test/integration/chunking/test/index.test.js
index ff60ae5e00..4ed2618632 100644
--- a/test/integration/chunking/test/index.test.js
+++ b/test/integration/chunking/test/index.test.js
@@ -16,8 +16,8 @@ let buildId
 let chunks
 let stats
 
-const existsChunkNamed = name => {
-  return chunks.some(chunk => new RegExp(name).test(chunk))
+const existsChunkNamed = (name) => {
+  return chunks.some((chunk) => new RegExp(name).test(chunk))
 }
 
 describe('Chunking', () => {
@@ -26,7 +26,7 @@ describe('Chunking', () => {
       // If a previous build has left chunks behind, delete them
       const oldChunks = await readdir(join(appDir, '.next', 'static', 'chunks'))
       await Promise.all(
-        oldChunks.map(chunk => {
+        oldChunks.map((chunk) => {
           return unlink(join(appDir, '.next', 'static', 'chunks', chunk))
         })
       )
@@ -41,7 +41,7 @@ describe('Chunking', () => {
     console.error(stderr)
     stats = (await readFile(join(appDir, '.next', 'stats.json'), 'utf8'))
       // fixes backslashes in keyNames not being escaped on windows
-      .replace(/"static\\(.*?":?)/g, match => match.replace(/\\/g, '\\\\'))
+      .replace(/"static\\(.*?":?)/g, (match) => match.replace(/\\/g, '\\\\'))
 
     stats = JSON.parse(stats)
     buildId = await readFile(join(appDir, '.next/BUILD_ID'), 'utf8')
@@ -49,7 +49,7 @@ describe('Chunking', () => {
   })
 
   it('should use all url friendly names', () => {
-    expect(chunks).toEqual(chunks.map(name => encodeURIComponent(name)))
+    expect(chunks).toEqual(chunks.map((name) => encodeURIComponent(name)))
   })
 
   it('should create a framework chunk', () => {
@@ -85,8 +85,8 @@ describe('Chunking', () => {
     expect(
       [].slice
         .call($('link[rel="preload"][as="script"]'))
-        .map(e => e.attribs.href)
-        .some(entry => entry.includes('_buildManifest'))
+        .map((e) => e.attribs.href)
+        .some((entry) => entry.includes('_buildManifest'))
     ).toBe(false)
   })
 
@@ -98,18 +98,18 @@ describe('Chunking', () => {
     const $ = cheerio.load(indexPage)
     expect(
       Array.from($('script'))
-        .map(e => e.attribs.src)
-        .some(entry => entry && entry.includes('_buildManifest'))
+        .map((e) => e.attribs.src)
+        .some((entry) => entry && entry.includes('_buildManifest'))
     ).toBe(true)
   })
 
   it('should not include more than one instance of react-dom', async () => {
-    const misplacedReactDom = stats.chunks.some(chunk => {
+    const misplacedReactDom = stats.chunks.some((chunk) => {
       if (chunk.names.includes('framework')) {
         // disregard react-dom in framework--it's supposed to be there
         return false
       }
-      return chunk.modules.some(module => {
+      return chunk.modules.some((module) => {
         return /react-dom/.test(module.name)
       })
     })
diff --git a/test/integration/client-404/test/client-navigation.js b/test/integration/client-404/test/client-navigation.js
index 54b228f1d2..84abab330b 100644
--- a/test/integration/client-404/test/client-navigation.js
+++ b/test/integration/client-404/test/client-navigation.js
@@ -1,7 +1,7 @@
 /* eslint-env jest */
 import webdriver from 'next-webdriver'
 
-export default context => {
+export default (context) => {
   describe('Client Navigation 404', () => {
     describe('should show 404 upon client replacestate', () => {
       it('should navigate the page', async () => {
diff --git a/test/integration/client-navigation/lib/async-function.js b/test/integration/client-navigation/lib/async-function.js
index 2e92e96574..7d702fba43 100644
--- a/test/integration/client-navigation/lib/async-function.js
+++ b/test/integration/client-navigation/lib/async-function.js
@@ -1,3 +1,3 @@
-module.exports = async function() {
+module.exports = async function () {
   return 'test'
 }
diff --git a/test/integration/client-navigation/pages/async-props.js b/test/integration/client-navigation/pages/async-props.js
index f4d56163ac..13e85ff962 100644
--- a/test/integration/client-navigation/pages/async-props.js
+++ b/test/integration/client-navigation/pages/async-props.js
@@ -11,7 +11,7 @@ export default class AsyncProps extends React.Component {
 }
 
 function fetchData() {
-  const p = new Promise(resolve => {
+  const p = new Promise((resolve) => {
     setTimeout(() => resolve({ name: 'Diego Milito' }), 10)
   })
   return p
diff --git a/test/integration/client-navigation/pages/head.js b/test/integration/client-navigation/pages/head.js
index ae698dc67e..565abdc9d1 100644
--- a/test/integration/client-navigation/pages/head.js
+++ b/test/integration/client-navigation/pages/head.js
@@ -105,7 +105,7 @@ export default () => (
       <link rel="stylesheet" href="dedupe-style.css" key="my-style" />
 
       {/* such style can be used for alternate links on _app vs individual pages */}
-      {['pl', 'en'].map(language => (
+      {['pl', 'en'].map((language) => (
         <link
           rel="alternate"
           key={language}
@@ -113,7 +113,7 @@ export default () => (
           href={'/first/' + language}
         />
       ))}
-      {['pl', 'en'].map(language => (
+      {['pl', 'en'].map((language) => (
         <link
           rel="alternate"
           key={language}
diff --git a/test/integration/client-navigation/pages/instance-get-initial-props.js b/test/integration/client-navigation/pages/instance-get-initial-props.js
index bce76bde7b..fbd1859ff3 100644
--- a/test/integration/client-navigation/pages/instance-get-initial-props.js
+++ b/test/integration/client-navigation/pages/instance-get-initial-props.js
@@ -11,7 +11,7 @@ export default class InstanceInitialPropsPage extends React.Component {
 }
 
 function fetchData() {
-  const p = new Promise(resolve => {
+  const p = new Promise((resolve) => {
     setTimeout(() => resolve({ name: 'Anderson Leite' }), 10)
   })
   return p
diff --git a/test/integration/client-navigation/pages/memo-component.js b/test/integration/client-navigation/pages/memo-component.js
index 580568e24a..6bb12c4611 100644
--- a/test/integration/client-navigation/pages/memo-component.js
+++ b/test/integration/client-navigation/pages/memo-component.js
@@ -1,3 +1,3 @@
 import React from 'react'
 
-export default React.memo(props => <span {...props}>Memo component</span>)
+export default React.memo((props) => <span {...props}>Memo component</span>)
diff --git a/test/integration/client-navigation/pages/nav/hash-changes.js b/test/integration/client-navigation/pages/nav/hash-changes.js
index 66d65cf095..d09ebb6163 100644
--- a/test/integration/client-navigation/pages/nav/hash-changes.js
+++ b/test/integration/client-navigation/pages/nav/hash-changes.js
@@ -33,14 +33,14 @@ export default class SelfReload extends Component {
           <a id="scroll-to-name-item-400">Go to name item 400</a>
         </Link>
         <p>COUNT: {this.props.count}</p>
-        {Array.from({ length: 500 }, (x, i) => i + 1).map(i => {
+        {Array.from({ length: 500 }, (x, i) => i + 1).map((i) => {
           return (
             <div key={`item-${i}`} id={`item-${i}`}>
               {i}
             </div>
           )
         })}
-        {Array.from({ length: 500 }, (x, i) => i + 1).map(i => {
+        {Array.from({ length: 500 }, (x, i) => i + 1).map((i) => {
           return (
             <div key={`item-${i}`} name={`name-item-${i}`}>
               {i}
diff --git a/test/integration/client-navigation/pages/nav/head-1.js b/test/integration/client-navigation/pages/nav/head-1.js
index a32795a445..b1b9bbfd83 100644
--- a/test/integration/client-navigation/pages/nav/head-1.js
+++ b/test/integration/client-navigation/pages/nav/head-1.js
@@ -2,7 +2,7 @@ import React from 'react'
 import Head from 'next/head'
 import Link from 'next/link'
 
-export default props => (
+export default (props) => (
   <div id="head-1">
     <Head>
       <meta name="description" content="Head One" />
diff --git a/test/integration/client-navigation/pages/nav/head-2.js b/test/integration/client-navigation/pages/nav/head-2.js
index ea5e782b4e..e0d29a74da 100644
--- a/test/integration/client-navigation/pages/nav/head-2.js
+++ b/test/integration/client-navigation/pages/nav/head-2.js
@@ -2,7 +2,7 @@ import React from 'react'
 import Head from 'next/head'
 import Link from 'next/link'
 
-export default props => (
+export default (props) => (
   <div id="head-2">
     <Head>
       <meta name="description" content="Head Two" />
diff --git a/test/integration/client-navigation/pages/nav/on-click.js b/test/integration/client-navigation/pages/nav/on-click.js
index 45f8042c36..401f54f0d4 100644
--- a/test/integration/client-navigation/pages/nav/on-click.js
+++ b/test/integration/client-navigation/pages/nav/on-click.js
@@ -26,7 +26,7 @@ export default class OnClick extends Component {
         <Link href="/nav/on-click">
           <a
             id="on-click-link-prevent-default"
-            onClick={e => {
+            onClick={(e) => {
               e.preventDefault()
               this.setState({ stateCounter: stateCounter + 1 })
             }}
diff --git a/test/integration/client-navigation/pages/nav/pass-href-prop.js b/test/integration/client-navigation/pages/nav/pass-href-prop.js
index 84c6796fab..ce9acc1ef6 100644
--- a/test/integration/client-navigation/pages/nav/pass-href-prop.js
+++ b/test/integration/client-navigation/pages/nav/pass-href-prop.js
@@ -1,7 +1,7 @@
 import Link from 'next/link'
 
 const UnexpectedNestedA = () => {
-  const UnexpectedWrapper = props => {
+  const UnexpectedWrapper = (props) => {
     const { href, id } = props
     const safeProps = { href, id }
     return <a {...safeProps}>{props.children}</a>
diff --git a/test/integration/client-navigation/pages/nav/redirect.js b/test/integration/client-navigation/pages/nav/redirect.js
index 8e9d634a7f..b34c2bf681 100644
--- a/test/integration/client-navigation/pages/nav/redirect.js
+++ b/test/integration/client-navigation/pages/nav/redirect.js
@@ -2,7 +2,7 @@ import Router from 'next/router'
 
 const Page = () => <p>This is the page</p>
 
-Page.getInitialProps = ctx => {
+Page.getInitialProps = (ctx) => {
   if (ctx.res) {
     ctx.res.writeHead(302, { Location: '/nav/about' })
     ctx.res.end()
diff --git a/test/integration/client-navigation/pages/nav/with-hoc.js b/test/integration/client-navigation/pages/nav/with-hoc.js
index 761823e24a..d2b1fffa28 100644
--- a/test/integration/client-navigation/pages/nav/with-hoc.js
+++ b/test/integration/client-navigation/pages/nav/with-hoc.js
@@ -1,7 +1,7 @@
 import { withRouter } from 'next/router'
 
 const Link = withRouter(({ router, children, href }) => {
-  const handleClick = e => {
+  const handleClick = (e) => {
     e.preventDefault()
     router.push(href)
   }
diff --git a/test/integration/client-navigation/test/index.test.js b/test/integration/client-navigation/test/index.test.js
index e4b885b566..25c69cbb1c 100644
--- a/test/integration/client-navigation/test/index.test.js
+++ b/test/integration/client-navigation/test/index.test.js
@@ -57,7 +57,7 @@ describe('Client Navigation', () => {
       '/nested-cdm',
     ]
     await Promise.all(
-      prerender.map(route => renderViaHTTP(context.appPort, route))
+      prerender.map((route) => renderViaHTTP(context.appPort, route))
     )
   })
   afterAll(() => killApp(context.server))
@@ -639,10 +639,7 @@ describe('Client Navigation', () => {
         .text()
       expect(counter).toBe('Counter: 2')
 
-      counter = await browser
-        .back()
-        .elementByCss('#counter')
-        .text()
+      counter = await browser.back().elementByCss('#counter').text()
       expect(counter).toBe('Counter: 1')
 
       const getInitialPropsRunCount = await browser
diff --git a/test/integration/client-navigation/test/rendering.js b/test/integration/client-navigation/test/rendering.js
index 82c44d2445..e08b2e6c3d 100644
--- a/test/integration/client-navigation/test/rendering.js
+++ b/test/integration/client-navigation/test/rendering.js
@@ -4,7 +4,7 @@ import cheerio from 'cheerio'
 import { BUILD_MANIFEST, REACT_LOADABLE_MANIFEST } from 'next/constants'
 import { join } from 'path'
 
-export default function(render, fetch) {
+export default function (render, fetch) {
   async function get$(path, query) {
     const html = await render(path, query)
     return cheerio.load(html)
@@ -206,9 +206,7 @@ export default function(render, fetch) {
       const expectedErrorMessage =
         'Circular structure in \\"getInitialProps\\" result of page \\"/circular-json-error\\".'
       expect(
-        $('#__NEXT_DATA__')
-          .text()
-          .includes(expectedErrorMessage)
+        $('#__NEXT_DATA__').text().includes(expectedErrorMessage)
       ).toBeTruthy()
     })
 
@@ -217,9 +215,7 @@ export default function(render, fetch) {
       const expectedErrorMessage =
         '\\"InstanceInitialPropsPage.getInitialProps()\\" is defined as an instance method - visit https://err.sh/zeit/next.js/get-initial-props-as-an-instance-method for more information.'
       expect(
-        $('#__NEXT_DATA__')
-          .text()
-          .includes(expectedErrorMessage)
+        $('#__NEXT_DATA__').text().includes(expectedErrorMessage)
       ).toBeTruthy()
     })
 
@@ -228,9 +224,7 @@ export default function(render, fetch) {
       const expectedErrorMessage =
         '\\"EmptyInitialPropsPage.getInitialProps()\\" should resolve to an object. But found \\"null\\" instead.'
       expect(
-        $('#__NEXT_DATA__')
-          .text()
-          .includes(expectedErrorMessage)
+        $('#__NEXT_DATA__').text().includes(expectedErrorMessage)
       ).toBeTruthy()
     })
 
@@ -330,10 +324,10 @@ export default function(render, fetch) {
       }
 
       const responses = await Promise.all(
-        resources.map(resource => fetch(resource))
+        resources.map((resource) => fetch(resource))
       )
 
-      responses.forEach(res => {
+      responses.forEach((res) => {
         try {
           expect(res.headers.get('Cache-Control')).toBe(
             'no-store, must-revalidate'
diff --git a/test/integration/config-promise-error/next.config.js b/test/integration/config-promise-error/next.config.js
index 0d8c81c25e..5f62c10ecb 100644
--- a/test/integration/config-promise-error/next.config.js
+++ b/test/integration/config-promise-error/next.config.js
@@ -1,5 +1,5 @@
 module.exports = (phase, { isServer }) => {
-  return new Promise(resolve => {
+  return new Promise((resolve) => {
     resolve({ target: 'serverless' })
   })
 }
diff --git a/test/integration/conformance/pages/page3.js b/test/integration/conformance/pages/page3.js
index 91ce805416..03d534597c 100644
--- a/test/integration/conformance/pages/page3.js
+++ b/test/integration/conformance/pages/page3.js
@@ -1,5 +1,5 @@
 import Link from 'next/link'
-import('lodash').then(_ => console.log(_.chunk(['a', 'b', 'c', 'd'], 2)))
+import('lodash').then((_) => console.log(_.chunk(['a', 'b', 'c', 'd'], 2)))
 
 const Page = () => {
   return (
diff --git a/test/integration/create-next-app/index.test.js b/test/integration/create-next-app/index.test.js
index a2f8b6a1ac..373c409d64 100644
--- a/test/integration/create-next-app/index.test.js
+++ b/test/integration/create-next-app/index.test.js
@@ -12,7 +12,7 @@ const run = (cwd, ...args) => execa('node', [cli, ...args], { cwd })
 const runStarter = (cwd, ...args) => {
   const res = run(cwd, ...args)
 
-  res.stdout.on('data', data => {
+  res.stdout.on('data', (data) => {
     const stdout = data.toString()
 
     if (/Pick a template/.test(stdout)) {
@@ -24,12 +24,7 @@ const runStarter = (cwd, ...args) => {
 }
 
 async function usingTempDir(fn) {
-  const folder = path.join(
-    os.tmpdir(),
-    Math.random()
-      .toString(36)
-      .substring(2)
-  )
+  const folder = path.join(os.tmpdir(), Math.random().toString(36).substring(2))
   await fs.mkdirp(folder)
   try {
     return await fn(folder)
@@ -40,7 +35,7 @@ async function usingTempDir(fn) {
 
 describe('create next app', () => {
   it('non-empty directory', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'non-empty-directory'
       await fs.mkdirp(path.join(cwd, projectName))
       const pkg = path.join(cwd, projectName, 'package.json')
@@ -59,7 +54,7 @@ describe('create next app', () => {
   // stdin is piped instead of inherited on windows
   if (process.platform !== 'win32') {
     it('empty directory', async () => {
-      await usingTempDir(async cwd => {
+      await usingTempDir(async (cwd) => {
         const projectName = 'empty-directory'
         const res = await runStarter(cwd, projectName)
 
@@ -75,7 +70,7 @@ describe('create next app', () => {
   }
 
   it('invalid example name', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'invalid-example-name'
       expect.assertions(2)
       try {
@@ -90,7 +85,7 @@ describe('create next app', () => {
   })
 
   it('valid example', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'valid-example'
       const res = await run(cwd, projectName, '--example', 'basic-css')
       expect(res.exitCode).toBe(0)
@@ -109,7 +104,7 @@ describe('create next app', () => {
   })
 
   it('should allow example with GitHub URL', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'github-app'
       const res = await run(
         cwd,
@@ -135,7 +130,7 @@ describe('create next app', () => {
   })
 
   it('should allow example with GitHub URL and example-path', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'github-example-path'
       const res = await run(
         cwd,
@@ -163,7 +158,7 @@ describe('create next app', () => {
   })
 
   it('should use --example-path over the file path in the GitHub URL', async () => {
-    await usingTempDir(async cwd => {
+    await usingTempDir(async (cwd) => {
       const projectName = 'github-example-path-2'
       const res = await run(
         cwd,
@@ -194,7 +189,7 @@ describe('create next app', () => {
   // stdin is piped instead of inherited on windows
   if (process.platform !== 'win32') {
     it('should allow to manually select an example', async () => {
-      await usingTempDir(async cwd => {
+      await usingTempDir(async (cwd) => {
         const runExample = (...args) => {
           const res = run(cwd, ...args)
 
diff --git a/test/integration/css-client-nav/test/index.test.js b/test/integration/css-client-nav/test/index.test.js
index 4eb9f66572..e841f33cb1 100644
--- a/test/integration/css-client-nav/test/index.test.js
+++ b/test/integration/css-client-nav/test/index.test.js
@@ -96,11 +96,11 @@ describe('CSS Module client-side navigation in Production', () => {
       const cssPreloads = await browser.eval(
         `[].slice.call(document.querySelectorAll('link[rel=preload][href*=".css"]')).map(e=>e.as)`
       )
-      expect(cssPreloads.every(e => e === 'style')).toBe(true)
+      expect(cssPreloads.every((e) => e === 'style')).toBe(true)
       const cssPreloads2 = await browser.eval(
         `[].slice.call(document.querySelectorAll('link[rel=prefetch][href*=".css"]')).map(e=>e.as)`
       )
-      expect(cssPreloads2.every(e => e === 'style')).toBe(true)
+      expect(cssPreloads2.every((e) => e === 'style')).toBe(true)
 
       await browser.elementByCss('#link-red').click()
 
@@ -252,11 +252,11 @@ describe('CSS Module client-side navigation in Production (Modern)', () => {
       const cssPreloads = await browser.eval(
         `[].slice.call(document.querySelectorAll('link[rel=preload][href*=".css"]')).map(e=>e.as)`
       )
-      expect(cssPreloads.every(e => e === 'style')).toBe(true)
+      expect(cssPreloads.every((e) => e === 'style')).toBe(true)
       const cssPreloads2 = await browser.eval(
         `[].slice.call(document.querySelectorAll('link[rel=prefetch][href*=".css"]')).map(e=>e.as)`
       )
-      expect(cssPreloads2.every(e => e === 'style')).toBe(true)
+      expect(cssPreloads2.every((e) => e === 'style')).toBe(true)
 
       await browser.elementByCss('#link-red').click()
 
diff --git a/test/integration/css-customization/test/index.test.js b/test/integration/css-customization/test/index.test.js
index b62ab5c36c..015d5bfd20 100644
--- a/test/integration/css-customization/test/index.test.js
+++ b/test/integration/css-customization/test/index.test.js
@@ -28,7 +28,7 @@ describe('CSS Customization', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -44,7 +44,7 @@ describe('CSS Customization', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+    const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
     expect(cssMapFiles.length).toBe(1)
     const cssMapContent = (
@@ -98,7 +98,7 @@ describe('Legacy Next-CSS Customization', () => {
     const cssFolder = join(appDir, '.next/static/chunks')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -127,7 +127,7 @@ describe('CSS Customization Array', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -143,7 +143,7 @@ describe('CSS Customization Array', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+    const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
     expect(cssMapFiles.length).toBe(1)
     const cssMapContent = (
@@ -197,7 +197,7 @@ describe('Bad CSS Customization', () => {
       'postcss-modules-extract-imports',
       'postcss-modules-local-by-default',
       'postcss-modules',
-    ].forEach(plugin => {
+    ].forEach((plugin) => {
       expect(stderr).toMatch(
         new RegExp(`Please remove the.*?${escapeStringRegexp(plugin)}`)
       )
@@ -208,7 +208,7 @@ describe('Bad CSS Customization', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -224,7 +224,7 @@ describe('Bad CSS Customization', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+    const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
     expect(cssMapFiles.length).toBe(1)
   })
diff --git a/test/integration/css-features/fixtures/browsers-new/pages/index.js b/test/integration/css-features/fixtures/browsers-new/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/css-features/fixtures/browsers-new/pages/index.js
+++ b/test/integration/css-features/fixtures/browsers-new/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/css-features/fixtures/browsers-old/pages/index.js b/test/integration/css-features/fixtures/browsers-old/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/css-features/fixtures/browsers-old/pages/index.js
+++ b/test/integration/css-features/fixtures/browsers-old/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/css-features/fixtures/cp-el-modules/pages/index.js b/test/integration/css-features/fixtures/cp-el-modules/pages/index.js
index cad0fc5061..26fbab0766 100644
--- a/test/integration/css-features/fixtures/cp-el-modules/pages/index.js
+++ b/test/integration/css-features/fixtures/cp-el-modules/pages/index.js
@@ -1,5 +1,5 @@
 import styles from './styles.module.css'
 
-export default function() {
+export default function () {
   return <div>{JSON.stringify(styles)}</div>
 }
diff --git a/test/integration/css-features/fixtures/cp-global-modules/pages/index.js b/test/integration/css-features/fixtures/cp-global-modules/pages/index.js
index cad0fc5061..26fbab0766 100644
--- a/test/integration/css-features/fixtures/cp-global-modules/pages/index.js
+++ b/test/integration/css-features/fixtures/cp-global-modules/pages/index.js
@@ -1,5 +1,5 @@
 import styles from './styles.module.css'
 
-export default function() {
+export default function () {
   return <div>{JSON.stringify(styles)}</div>
 }
diff --git a/test/integration/css-features/fixtures/cp-ie-11/pages/index.js b/test/integration/css-features/fixtures/cp-ie-11/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/css-features/fixtures/cp-ie-11/pages/index.js
+++ b/test/integration/css-features/fixtures/cp-ie-11/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/css-features/fixtures/cp-modern/pages/index.js b/test/integration/css-features/fixtures/cp-modern/pages/index.js
index d2ef69607d..7176cf7772 100644
--- a/test/integration/css-features/fixtures/cp-modern/pages/index.js
+++ b/test/integration/css-features/fixtures/cp-modern/pages/index.js
@@ -1,3 +1,3 @@
-export default function() {
+export default function () {
   return <div />
 }
diff --git a/test/integration/css-features/fixtures/module-import-global-invalid/pages/index.js b/test/integration/css-features/fixtures/module-import-global-invalid/pages/index.js
index cad0fc5061..26fbab0766 100644
--- a/test/integration/css-features/fixtures/module-import-global-invalid/pages/index.js
+++ b/test/integration/css-features/fixtures/module-import-global-invalid/pages/index.js
@@ -1,5 +1,5 @@
 import styles from './styles.module.css'
 
-export default function() {
+export default function () {
   return <div>{JSON.stringify(styles)}</div>
 }
diff --git a/test/integration/css-features/fixtures/module-import-global/pages/index.js b/test/integration/css-features/fixtures/module-import-global/pages/index.js
index cad0fc5061..26fbab0766 100644
--- a/test/integration/css-features/fixtures/module-import-global/pages/index.js
+++ b/test/integration/css-features/fixtures/module-import-global/pages/index.js
@@ -1,5 +1,5 @@
 import styles from './styles.module.css'
 
-export default function() {
+export default function () {
   return <div>{JSON.stringify(styles)}</div>
 }
diff --git a/test/integration/css-features/test/index.test.js b/test/integration/css-features/test/index.test.js
index bf4c4ac47e..399ae04948 100644
--- a/test/integration/css-features/test/index.test.js
+++ b/test/integration/css-features/test/index.test.js
@@ -29,7 +29,7 @@ describe('Browserslist: Old', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -61,7 +61,7 @@ describe('Browserslist: New', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -93,7 +93,7 @@ describe('Custom Properties: Pass-Through IE11', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -125,7 +125,7 @@ describe('Custom Properties: Pass-Through Modern', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -193,7 +193,7 @@ describe('CSS Modules: Import Global CSS', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
diff --git a/test/integration/css-fixtures/bad-custom-configuration-func/postcss.config.js b/test/integration/css-fixtures/bad-custom-configuration-func/postcss.config.js
index 9bf5d079ed..0d41554a32 100644
--- a/test/integration/css-fixtures/bad-custom-configuration-func/postcss.config.js
+++ b/test/integration/css-fixtures/bad-custom-configuration-func/postcss.config.js
@@ -1,3 +1,3 @@
-module.exports = function() {
+module.exports = function () {
   return { plugins: [] }
 }
diff --git a/test/integration/css-fixtures/with-tailwindcss-and-purgecss/postcss.config.js b/test/integration/css-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
index b39d3d7ff9..2f75132b35 100644
--- a/test/integration/css-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
+++ b/test/integration/css-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
@@ -6,7 +6,7 @@ module.exports = {
       '@fullhuman/postcss-purgecss',
       {
         content: [path.join(__dirname, './pages/**/*.{js,jsx,ts,tsx}')],
-        defaultExtractor: content => content.match(/[A-Za-z0-9-_:/]+/g) || [],
+        defaultExtractor: (content) => content.match(/[A-Za-z0-9-_:/]+/g) || [],
       },
     ],
   ],
diff --git a/test/integration/css-modules/test/index.test.js b/test/integration/css-modules/test/index.test.js
index a48b099944..8066466aee 100644
--- a/test/integration/css-modules/test/index.test.js
+++ b/test/integration/css-modules/test/index.test.js
@@ -48,7 +48,7 @@ describe('Basic CSS Module Support', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -104,7 +104,7 @@ describe('3rd Party CSS Module Support', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -320,7 +320,7 @@ describe('Valid CSS Module Usage from within node_modules', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -373,7 +373,7 @@ describe('Valid Nested CSS Module Usage from within node_modules', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -406,7 +406,7 @@ describe('CSS Module Composes Usage (Basic)', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -439,7 +439,7 @@ describe('CSS Module Composes Usage (External)', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -487,7 +487,7 @@ describe('Dynamic Route CSS Module Usage', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -537,7 +537,7 @@ describe('Catch-all Route CSS Module Usage', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
diff --git a/test/integration/css/test/index.test.js b/test/integration/css/test/index.test.js
index dd1359462c..2e5b78f43f 100644
--- a/test/integration/css/test/index.test.js
+++ b/test/integration/css/test/index.test.js
@@ -40,7 +40,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       expect(await readFile(join(cssFolder, cssFiles[0]), 'utf8')).toContain(
@@ -68,7 +68,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       expect(await readFile(join(cssFolder, cssFiles[0]), 'utf8')).toContain(
@@ -96,7 +96,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -125,7 +125,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -156,7 +156,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -174,7 +174,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
       const cssMapContent = (
@@ -223,7 +223,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -549,7 +549,7 @@ describe('CSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -561,11 +561,8 @@ describe('CSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -598,7 +595,7 @@ describe('CSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -610,11 +607,8 @@ describe('CSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -647,7 +641,7 @@ describe('CSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -659,11 +653,8 @@ describe('CSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -695,7 +686,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -722,7 +713,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -913,7 +904,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -929,7 +920,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
     })
@@ -954,7 +945,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -971,7 +962,7 @@ describe('CSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
     })
diff --git a/test/integration/custom-routes/server.js b/test/integration/custom-routes/server.js
index e07441ae67..d31590fd3d 100644
--- a/test/integration/custom-routes/server.js
+++ b/test/integration/custom-routes/server.js
@@ -2,11 +2,11 @@ const path = require('path')
 const http = require('http')
 
 const server = http.createServer((req, res) => {
-  const pagePath = page => path.join('.next/serverless/pages/', page)
-  const render = page => {
+  const pagePath = (page) => path.join('.next/serverless/pages/', page)
+  const render = (page) => {
     require(`./${pagePath(page)}`).render(req, res)
   }
-  const apiCall = page => {
+  const apiCall = (page) => {
     require(`./${pagePath(page)}`).default(req, res)
   }
 
diff --git a/test/integration/custom-routes/test/index.test.js b/test/integration/custom-routes/test/index.test.js
index e78ce75dc5..c2e4b9f773 100644
--- a/test/integration/custom-routes/test/index.test.js
+++ b/test/integration/custom-routes/test/index.test.js
@@ -231,11 +231,7 @@ const runTests = (isDev = false) => {
       '/query-rewrite/first/second?section=overridden&name=overridden&first=overridden&second=overridden&keep=me'
     )
 
-    const data = JSON.parse(
-      cheerio
-        .load(html)('p')
-        .text()
-    )
+    const data = JSON.parse(cheerio.load(html)('p').text())
     expect(data).toEqual({
       first: 'first',
       second: 'second',
@@ -367,7 +363,7 @@ const runTests = (isDev = false) => {
     const res = await fetchViaHTTP(appPort, '/proxy-me/first?keep=me&and=me')
     expect(res.status).toBe(200)
     expect(
-      [...externalServerHits].map(u => {
+      [...externalServerHits].map((u) => {
         const { pathname, query } = url.parse(u, true)
         return {
           pathname,
@@ -462,11 +458,7 @@ const runTests = (isDev = false) => {
       appPort,
       '/unnamed-params/nested/first/second/hello/world'
     )
-    const params = JSON.parse(
-      cheerio
-        .load(html)('p')
-        .text()
-    )
+    const params = JSON.parse(cheerio.load(html)('p').text())
     expect(params).toEqual({ test: 'hello' })
   })
 
@@ -945,7 +937,7 @@ describe('Custom routes', () => {
       res.end('hi from external')
     })
     await new Promise((resolve, reject) => {
-      externalServer.listen(externalServerPort, error => {
+      externalServer.listen(externalServerPort, (error) => {
         if (error) return reject(error)
         resolve()
       })
@@ -999,7 +991,7 @@ describe('Custom routes', () => {
       stdout = buildStdout
       appPort = await findPort()
       app = await nextStart(appDir, appPort, {
-        onStdout: msg => {
+        onStdout: (msg) => {
           stdout += msg
         },
       })
@@ -1036,11 +1028,7 @@ describe('Custom routes', () => {
 
     it('should apply rewrites in lambda correctly for page route', async () => {
       const html = await renderViaHTTP(appPort, '/query-rewrite/first/second')
-      const data = JSON.parse(
-        cheerio
-          .load(html)('p')
-          .text()
-      )
+      const data = JSON.parse(cheerio.load(html)('p').text())
       expect(data).toEqual({
         first: 'first',
         second: 'second',
@@ -1081,7 +1069,7 @@ describe('Custom routes', () => {
   })
 
   describe('should load custom routes when only one type is used', () => {
-    const runSoloTests = isDev => {
+    const runSoloTests = (isDev) => {
       const buildAndStart = async () => {
         if (isDev) {
           appPort = await findPort()
diff --git a/test/integration/custom-server/server.js b/test/integration/custom-server/server.js
index c0117310ea..0b34500af9 100644
--- a/test/integration/custom-server/server.js
+++ b/test/integration/custom-server/server.js
@@ -47,7 +47,7 @@ app.prepare().then(() => {
     handleNextRequests(req, res)
   })
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) {
       throw err
     }
diff --git a/test/integration/duplicate-pages/test/index.test.js b/test/integration/duplicate-pages/test/index.test.js
index 28b72f5900..dd0c7a50db 100644
--- a/test/integration/duplicate-pages/test/index.test.js
+++ b/test/integration/duplicate-pages/test/index.test.js
@@ -24,7 +24,7 @@ describe('Handles Duplicate Pages', () => {
   describe('dev mode', () => {
     it('Shows warning in development', async () => {
       let output
-      const handleOutput = msg => {
+      const handleOutput = (msg) => {
         output += msg
       }
       const appPort = await findPort()
diff --git a/test/integration/dynamic-optional-routing/test/index.test.js b/test/integration/dynamic-optional-routing/test/index.test.js
index ba5e348588..7c26da5ee7 100644
--- a/test/integration/dynamic-optional-routing/test/index.test.js
+++ b/test/integration/dynamic-optional-routing/test/index.test.js
@@ -163,10 +163,10 @@ describe('Dynamic Optional Routing', () => {
     afterAll(() => killApp(app))
 
     runTests()
-    runInvalidPagesTests(async appDir => {
+    runInvalidPagesTests(async (appDir) => {
       let stderr = ''
       await launchApp(appDir, await findPort(), {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
@@ -193,7 +193,7 @@ describe('Dynamic Optional Routing', () => {
     afterAll(() => killApp(app))
 
     runTests()
-    runInvalidPagesTests(async appDir =>
+    runInvalidPagesTests(async (appDir) =>
       nextBuild(appDir, [], { stderr: true })
     )
   })
diff --git a/test/integration/dynamic-routing/pages/on-mount/[post].js b/test/integration/dynamic-routing/pages/on-mount/[post].js
index 1016ca9f7a..1bb5e3cd4b 100644
--- a/test/integration/dynamic-routing/pages/on-mount/[post].js
+++ b/test/integration/dynamic-routing/pages/on-mount/[post].js
@@ -6,7 +6,7 @@ export default () => {
   return (
     <>
       <p>onmpost: {query.post || 'pending'}</p>
-      {Array.from({ length: 500 }, (x, i) => i + 1).map(i => {
+      {Array.from({ length: 500 }, (x, i) => i + 1).map((i) => {
         return (
           <div key={`item-${i}`} id={`item-${i}`}>
             {i}
diff --git a/test/integration/empty-object-getInitialProps/test/index.test.js b/test/integration/empty-object-getInitialProps/test/index.test.js
index 7a51283c6f..8f65540e78 100644
--- a/test/integration/empty-object-getInitialProps/test/index.test.js
+++ b/test/integration/empty-object-getInitialProps/test/index.test.js
@@ -17,7 +17,7 @@ let output = ''
 let appPort
 let app
 
-const handleOutput = msg => {
+const handleOutput = (msg) => {
   output += msg
 }
 
diff --git a/test/integration/env-config/app/pages/api/all.js b/test/integration/env-config/app/pages/api/all.js
index a80843c772..61d66efb0e 100644
--- a/test/integration/env-config/app/pages/api/all.js
+++ b/test/integration/env-config/app/pages/api/all.js
@@ -22,7 +22,7 @@ const variables = [
 
 const items = {}
 
-variables.forEach(variable => {
+variables.forEach((variable) => {
   items[variable] = process.env[variable]
 })
 
diff --git a/test/integration/env-config/app/pages/index.js b/test/integration/env-config/app/pages/index.js
index f087c9c363..c3e6932677 100644
--- a/test/integration/env-config/app/pages/index.js
+++ b/test/integration/env-config/app/pages/index.js
@@ -23,7 +23,7 @@ const variables = [
 export async function getStaticProps() {
   const items = {}
 
-  variables.forEach(variable => {
+  variables.forEach((variable) => {
     if (process.env[variable]) {
       items[variable] = process.env[variable]
     }
diff --git a/test/integration/env-config/app/pages/some-ssg.js b/test/integration/env-config/app/pages/some-ssg.js
index f087c9c363..c3e6932677 100644
--- a/test/integration/env-config/app/pages/some-ssg.js
+++ b/test/integration/env-config/app/pages/some-ssg.js
@@ -23,7 +23,7 @@ const variables = [
 export async function getStaticProps() {
   const items = {}
 
-  variables.forEach(variable => {
+  variables.forEach((variable) => {
     if (process.env[variable]) {
       items[variable] = process.env[variable]
     }
diff --git a/test/integration/env-config/app/pages/some-ssp.js b/test/integration/env-config/app/pages/some-ssp.js
index 03e75f4f7d..10cfebf896 100644
--- a/test/integration/env-config/app/pages/some-ssp.js
+++ b/test/integration/env-config/app/pages/some-ssp.js
@@ -23,7 +23,7 @@ const variables = [
 export async function getServerSideProps() {
   const items = {}
 
-  variables.forEach(variable => {
+  variables.forEach((variable) => {
     if (process.env[variable]) {
       items[variable] = process.env[variable]
     }
diff --git a/test/integration/env-config/test/index.test.js b/test/integration/env-config/test/index.test.js
index e687a7b90f..cb130ab7a1 100644
--- a/test/integration/env-config/test/index.test.js
+++ b/test/integration/env-config/test/index.test.js
@@ -21,13 +21,9 @@ let appPort
 let buildId
 const appDir = join(__dirname, '../app')
 
-const getEnvFromHtml = async path => {
+const getEnvFromHtml = async (path) => {
   const html = await renderViaHTTP(appPort, path)
-  return JSON.parse(
-    cheerio
-      .load(html)('p')
-      .text()
-  )
+  return JSON.parse(cheerio.load(html)('p').text())
 }
 
 const runTests = (mode = 'dev') => {
@@ -35,7 +31,7 @@ const runTests = (mode = 'dev') => {
   const isTestEnv = mode === 'test'
   const isDev = isDevOnly || isTestEnv
 
-  const checkEnvData = data => {
+  const checkEnvData = (data) => {
     expect(data.ENV_FILE_KEY).toBe('env')
     expect(data.LOCAL_ENV_FILE_KEY).toBe(!isTestEnv ? 'localenv' : undefined)
     expect(data.DEVELOPMENT_ENV_FILE_KEY).toBe(
diff --git a/test/integration/export-serverless/next.config.js b/test/integration/export-serverless/next.config.js
index 0428bc53ef..bbf005a73f 100644
--- a/test/integration/export-serverless/next.config.js
+++ b/test/integration/export-serverless/next.config.js
@@ -1,11 +1,11 @@
 const { PHASE_DEVELOPMENT_SERVER } = require('next/constants')
 
-module.exports = phase => {
+module.exports = (phase) => {
   return {
     target: 'serverless',
     distDir: phase === PHASE_DEVELOPMENT_SERVER ? '.next-dev' : '.next',
     exportTrailingSlash: true,
-    exportPathMap: function() {
+    exportPathMap: function () {
       return {
         '/': { page: '/' },
         '/about': { page: '/about' },
diff --git a/test/integration/export-serverless/test/api-routes.js b/test/integration/export-serverless/test/api-routes.js
index 0b2c9a6fa2..2957d55a7c 100644
--- a/test/integration/export-serverless/test/api-routes.js
+++ b/test/integration/export-serverless/test/api-routes.js
@@ -2,7 +2,7 @@
 import { join } from 'path'
 import { File, runNextCommand } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('API routes export', () => {
     const nextConfig = new File(join(context.appDir, 'next.config.js'))
 
diff --git a/test/integration/export-serverless/test/browser.js b/test/integration/export-serverless/test/browser.js
index bc13e9b943..9942566558 100644
--- a/test/integration/export-serverless/test/browser.js
+++ b/test/integration/export-serverless/test/browser.js
@@ -2,7 +2,7 @@
 import webdriver from 'next-webdriver'
 import { check, getBrowserBodyText } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('Render via browser', () => {
     it('should render the home page', async () => {
       const browser = await webdriver(context.port, '/')
diff --git a/test/integration/export-serverless/test/dev.js b/test/integration/export-serverless/test/dev.js
index af68635a2c..2a1b45076f 100644
--- a/test/integration/export-serverless/test/dev.js
+++ b/test/integration/export-serverless/test/dev.js
@@ -3,12 +3,12 @@ import webdriver from 'next-webdriver'
 import { renderViaHTTP, getBrowserBodyText, check } from 'next-test-utils'
 import cheerio from 'cheerio'
 
-const loadJSONInPage = pageContent => {
+const loadJSONInPage = (pageContent) => {
   const page = cheerio.load(pageContent)
   return JSON.parse(page('#__next').text())
 }
 
-export default function(context) {
+export default function (context) {
   describe('Render in development mode', () => {
     it('should render the home page', async () => {
       const browser = await webdriver(context.port, '/')
diff --git a/test/integration/export-serverless/test/dynamic.js b/test/integration/export-serverless/test/dynamic.js
index 524413690d..e2368d6306 100644
--- a/test/integration/export-serverless/test/dynamic.js
+++ b/test/integration/export-serverless/test/dynamic.js
@@ -2,7 +2,7 @@
 import { join } from 'path'
 import { File, runNextCommand } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('Dynamic routes export', () => {
     const nextConfig = new File(join(context.appDir, 'next.config.js'))
     beforeEach(() => {
@@ -17,7 +17,7 @@ export default function(context) {
       const { stderr } = await runNextCommand(
         ['export', context.appDir, '--outdir', outdir],
         { stderr: true }
-      ).catch(err => err)
+      ).catch((err) => err)
 
       expect(stderr).toContain(
         'https://err.sh/zeit/next.js/export-path-mismatch'
diff --git a/test/integration/export-serverless/test/index.test.js b/test/integration/export-serverless/test/index.test.js
index 131a4dd68f..634c40980f 100644
--- a/test/integration/export-serverless/test/index.test.js
+++ b/test/integration/export-serverless/test/index.test.js
@@ -34,7 +34,7 @@ describe('Static Export', () => {
     const outdir = join(appDir, 'out')
     const tempfile = join(outdir, 'temp.txt')
 
-    await mkdir(outdir).catch(e => {
+    await mkdir(outdir).catch((e) => {
       if (e.code !== 'EEXIST') throw e
     })
     await writeFile(tempfile, 'Hello there')
@@ -43,7 +43,7 @@ describe('Static Export', () => {
     await nextExport(appDir, { outdir })
 
     let doesNotExist = false
-    await access(tempfile).catch(e => {
+    await access(tempfile).catch((e) => {
       if (e.code === 'ENOENT') doesNotExist = true
     })
     expect(doesNotExist).toBe(true)
diff --git a/test/integration/export-serverless/test/ssr.js b/test/integration/export-serverless/test/ssr.js
index c45bd437cf..ad1721f980 100644
--- a/test/integration/export-serverless/test/ssr.js
+++ b/test/integration/export-serverless/test/ssr.js
@@ -2,7 +2,7 @@
 import { renderViaHTTP } from 'next-test-utils'
 import cheerio from 'cheerio'
 
-export default function(context) {
+export default function (context) {
   describe('Render via SSR', () => {
     it('should render the home page', async () => {
       const html = await renderViaHTTP(context.port, '/')
diff --git a/test/integration/export/next.config.js b/test/integration/export/next.config.js
index f501eea43e..024fe7bbf7 100644
--- a/test/integration/export/next.config.js
+++ b/test/integration/export/next.config.js
@@ -1,6 +1,6 @@
 const { PHASE_DEVELOPMENT_SERVER } = require('next/constants')
 
-module.exports = phase => {
+module.exports = (phase) => {
   return {
     distDir: phase === PHASE_DEVELOPMENT_SERVER ? '.next-dev' : '.next',
     publicRuntimeConfig: {
@@ -10,7 +10,7 @@ module.exports = phase => {
       bar: 'bar',
     },
     exportTrailingSlash: true,
-    exportPathMap: function() {
+    exportPathMap: function () {
       return {
         '/': { page: '/' },
         '/about': { page: '/about' },
diff --git a/test/integration/export/pages/about.js b/test/integration/export/pages/about.js
index a9dd0852d4..1003e4e457 100644
--- a/test/integration/export/pages/about.js
+++ b/test/integration/export/pages/about.js
@@ -13,7 +13,7 @@ const About = ({ bar }) => (
   </div>
 )
 
-About.getInitialProps = async ctx => {
+About.getInitialProps = async (ctx) => {
   return { bar: serverRuntimeConfig.bar }
 }
 
diff --git a/test/integration/export/test/api-routes.js b/test/integration/export/test/api-routes.js
index 0b2c9a6fa2..2957d55a7c 100644
--- a/test/integration/export/test/api-routes.js
+++ b/test/integration/export/test/api-routes.js
@@ -2,7 +2,7 @@
 import { join } from 'path'
 import { File, runNextCommand } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('API routes export', () => {
     const nextConfig = new File(join(context.appDir, 'next.config.js'))
 
diff --git a/test/integration/export/test/browser.js b/test/integration/export/test/browser.js
index c1453ce3a2..f58c8be64e 100644
--- a/test/integration/export/test/browser.js
+++ b/test/integration/export/test/browser.js
@@ -2,7 +2,7 @@
 import webdriver from 'next-webdriver'
 import { check, getBrowserBodyText } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('Render via browser', () => {
     it('should render the home page', async () => {
       const browser = await webdriver(context.port, '/')
diff --git a/test/integration/export/test/dev.js b/test/integration/export/test/dev.js
index af68635a2c..2a1b45076f 100644
--- a/test/integration/export/test/dev.js
+++ b/test/integration/export/test/dev.js
@@ -3,12 +3,12 @@ import webdriver from 'next-webdriver'
 import { renderViaHTTP, getBrowserBodyText, check } from 'next-test-utils'
 import cheerio from 'cheerio'
 
-const loadJSONInPage = pageContent => {
+const loadJSONInPage = (pageContent) => {
   const page = cheerio.load(pageContent)
   return JSON.parse(page('#__next').text())
 }
 
-export default function(context) {
+export default function (context) {
   describe('Render in development mode', () => {
     it('should render the home page', async () => {
       const browser = await webdriver(context.port, '/')
diff --git a/test/integration/export/test/dynamic.js b/test/integration/export/test/dynamic.js
index 524413690d..e2368d6306 100644
--- a/test/integration/export/test/dynamic.js
+++ b/test/integration/export/test/dynamic.js
@@ -2,7 +2,7 @@
 import { join } from 'path'
 import { File, runNextCommand } from 'next-test-utils'
 
-export default function(context) {
+export default function (context) {
   describe('Dynamic routes export', () => {
     const nextConfig = new File(join(context.appDir, 'next.config.js'))
     beforeEach(() => {
@@ -17,7 +17,7 @@ export default function(context) {
       const { stderr } = await runNextCommand(
         ['export', context.appDir, '--outdir', outdir],
         { stderr: true }
-      ).catch(err => err)
+      ).catch((err) => err)
 
       expect(stderr).toContain(
         'https://err.sh/zeit/next.js/export-path-mismatch'
diff --git a/test/integration/export/test/index.test.js b/test/integration/export/test/index.test.js
index ad29dbaa17..62775b2c8d 100644
--- a/test/integration/export/test/index.test.js
+++ b/test/integration/export/test/index.test.js
@@ -35,7 +35,7 @@ describe('Static Export', () => {
   it('should delete existing exported files', async () => {
     const tempfile = join(outdir, 'temp.txt')
 
-    await mkdir(outdir).catch(e => {
+    await mkdir(outdir).catch((e) => {
       if (e.code !== 'EEXIST') throw e
     })
     await writeFile(tempfile, 'Hello there')
@@ -44,7 +44,7 @@ describe('Static Export', () => {
     await nextExport(appDir, { outdir })
 
     let doesNotExist = false
-    await access(tempfile).catch(e => {
+    await access(tempfile).catch((e) => {
       if (e.code === 'ENOENT') doesNotExist = true
     })
     expect(doesNotExist).toBe(true)
diff --git a/test/integration/export/test/ssr.js b/test/integration/export/test/ssr.js
index 9dfc6a3df6..9d29a5a3a3 100644
--- a/test/integration/export/test/ssr.js
+++ b/test/integration/export/test/ssr.js
@@ -2,7 +2,7 @@
 import { renderViaHTTP } from 'next-test-utils'
 import cheerio from 'cheerio'
 
-export default function(context) {
+export default function (context) {
   describe('Render via SSR', () => {
     it('should render the home page', async () => {
       const html = await renderViaHTTP(context.port, '/')
diff --git a/test/integration/fetch-polyfill-ky-universal/api-server.js b/test/integration/fetch-polyfill-ky-universal/api-server.js
index 4f766546b0..0733d1effe 100644
--- a/test/integration/fetch-polyfill-ky-universal/api-server.js
+++ b/test/integration/fetch-polyfill-ky-universal/api-server.js
@@ -5,7 +5,7 @@ const server = new http.Server(async (req, res) => {
   res.end(JSON.stringify({ foo: 'bar' }))
 })
 
-server.listen(port, err => {
+server.listen(port, (err) => {
   if (err) {
     throw err
   }
diff --git a/test/integration/fetch-polyfill/api-server.js b/test/integration/fetch-polyfill/api-server.js
index af954dae13..b0efc498f1 100644
--- a/test/integration/fetch-polyfill/api-server.js
+++ b/test/integration/fetch-polyfill/api-server.js
@@ -29,7 +29,7 @@ const server = new http.Server(async (req, res) => {
   res.end(JSON.stringify({ foo: 'bar' }))
 })
 
-server.listen(port, err => {
+server.listen(port, (err) => {
   if (err) {
     throw err
   }
diff --git a/test/integration/fetch-polyfill/pages/user/[username].js b/test/integration/fetch-polyfill/pages/user/[username].js
index 936a72b1ae..06045545e2 100644
--- a/test/integration/fetch-polyfill/pages/user/[username].js
+++ b/test/integration/fetch-polyfill/pages/user/[username].js
@@ -10,7 +10,7 @@ export async function getStaticPaths() {
 
   return {
     fallback: false,
-    paths: usernames.map(username => {
+    paths: usernames.map((username) => {
       return {
         params: {
           username,
diff --git a/test/integration/file-serving/test/index.test.js b/test/integration/file-serving/test/index.test.js
index cdf1956171..d2be0b79ae 100644
--- a/test/integration/file-serving/test/index.test.js
+++ b/test/integration/file-serving/test/index.test.js
@@ -19,7 +19,7 @@ const appDir = join(__dirname, '../')
 let appPort
 let app
 
-const expectStatus = async path => {
+const expectStatus = async (path) => {
   const containRegex = /(This page could not be found|Bad Request)/
   // test base mount point `public/`
   const res = await fetchViaHTTP(appPort, path)
diff --git a/test/integration/filesystempublicroutes/server.js b/test/integration/filesystempublicroutes/server.js
index 56c953923b..71b62d95d3 100644
--- a/test/integration/filesystempublicroutes/server.js
+++ b/test/integration/filesystempublicroutes/server.js
@@ -23,7 +23,7 @@ app.prepare().then(() => {
     handleNextRequests(req, res)
   })
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) {
       throw err
     }
diff --git a/test/integration/getserversideprops-preview/pages/index.js b/test/integration/getserversideprops-preview/pages/index.js
index d48204d469..c2eaabce7d 100644
--- a/test/integration/getserversideprops-preview/pages/index.js
+++ b/test/integration/getserversideprops-preview/pages/index.js
@@ -10,7 +10,7 @@ export function getServerSideProps({ res, preview, previewData }) {
   }
 }
 
-export default function({ hasProps, preview, previewData }) {
+export default function ({ hasProps, preview, previewData }) {
   if (!hasProps) {
     return <pre id="props-pre">Has No Props</pre>
   }
diff --git a/test/integration/getserversideprops-preview/pages/to-index.js b/test/integration/getserversideprops-preview/pages/to-index.js
index 2979fa90b0..3dc25e6c21 100644
--- a/test/integration/getserversideprops-preview/pages/to-index.js
+++ b/test/integration/getserversideprops-preview/pages/to-index.js
@@ -4,7 +4,7 @@ export function getServerSideProps() {
   return { props: {} }
 }
 
-export default function() {
+export default function () {
   return (
     <main>
       <Link href="/">
diff --git a/test/integration/getserversideprops-preview/test/index.test.js b/test/integration/getserversideprops-preview/test/index.test.js
index 33f2c70609..c456729975 100644
--- a/test/integration/getserversideprops-preview/test/index.test.js
+++ b/test/integration/getserversideprops-preview/test/index.test.js
@@ -71,7 +71,7 @@ function runTests(startServer = nextStart) {
     const originalCookies = res.headers.get('set-cookie').split(',')
     const cookies = originalCookies.map(cookie.parse)
 
-    expect(originalCookies.every(c => c.includes('; Secure;'))).toBe(true)
+    expect(originalCookies.every((c) => c.includes('; Secure;'))).toBe(true)
 
     expect(cookies.length).toBe(2)
     expect(cookies[0]).toMatchObject({ Path: '/', SameSite: 'None' })
@@ -194,10 +194,7 @@ describe('ServerSide Props Preview Mode', () => {
       const res = await fetchViaHTTP(appPort, '/api/preview', { lets: 'goooo' })
       expect(res.status).toBe(200)
 
-      const cookies = res.headers
-        .get('set-cookie')
-        .split(',')
-        .map(cookie.parse)
+      const cookies = res.headers.get('set-cookie').split(',').map(cookie.parse)
 
       expect(cookies.length).toBe(2)
       previewCookieString =
diff --git a/test/integration/getserversideprops/pages/blog/[post]/index.js b/test/integration/getserversideprops/pages/blog/[post]/index.js
index 6311696bad..354d3adef0 100644
--- a/test/integration/getserversideprops/pages/blog/[post]/index.js
+++ b/test/integration/getserversideprops/pages/blog/[post]/index.js
@@ -4,7 +4,7 @@ import { useRouter } from 'next/router'
 
 export async function getServerSideProps({ params }) {
   if (params.post === 'post-10') {
-    await new Promise(resolve => {
+    await new Promise((resolve) => {
       setTimeout(() => resolve(), 1000)
     })
   }
diff --git a/test/integration/getserversideprops/test/index.test.js b/test/integration/getserversideprops/test/index.test.js
index 8b0450beb2..fb503d5209 100644
--- a/test/integration/getserversideprops/test/index.test.js
+++ b/test/integration/getserversideprops/test/index.test.js
@@ -140,7 +140,7 @@ const navigateTest = (dev = false) => {
       '/blog/post-1/comment-1',
     ]
 
-    await Promise.all(toBuild.map(pg => renderViaHTTP(appPort, pg)))
+    await Promise.all(toBuild.map((pg) => renderViaHTTP(appPort, pg)))
 
     const browser = await webdriver(appPort, '/')
     let text = await browser.elementByCss('p').text()
diff --git a/test/integration/gip-identifier/test/index.test.js b/test/integration/gip-identifier/test/index.test.js
index 686aca3217..92a7ea0c72 100644
--- a/test/integration/gip-identifier/test/index.test.js
+++ b/test/integration/gip-identifier/test/index.test.js
@@ -21,7 +21,7 @@ let app
 let appPort
 let indexPageContent
 
-const runTests = isDev => {
+const runTests = (isDev) => {
   const getData = async () => {
     if (isDev) {
       appPort = await findPort()
diff --git a/test/integration/gssp-pageProps-merge/pages/gsp.js b/test/integration/gssp-pageProps-merge/pages/gsp.js
index 1bcf3bb50c..30b5587646 100644
--- a/test/integration/gssp-pageProps-merge/pages/gsp.js
+++ b/test/integration/gssp-pageProps-merge/pages/gsp.js
@@ -1,2 +1,2 @@
 export const getStaticProps = () => ({ props: { hi: 'hi' } })
-export default props => <p>{JSON.stringify(props)}</p>
+export default (props) => <p>{JSON.stringify(props)}</p>
diff --git a/test/integration/gssp-pageProps-merge/pages/gssp.js b/test/integration/gssp-pageProps-merge/pages/gssp.js
index 629b687ee2..ebf57fdd1f 100644
--- a/test/integration/gssp-pageProps-merge/pages/gssp.js
+++ b/test/integration/gssp-pageProps-merge/pages/gssp.js
@@ -1,2 +1,2 @@
 export const getServerSideProps = () => ({ props: { hi: 'hi' } })
-export default props => <p>{JSON.stringify(props)}</p>
+export default (props) => <p>{JSON.stringify(props)}</p>
diff --git a/test/integration/invalid-custom-routes/test/index.test.js b/test/integration/invalid-custom-routes/test/index.test.js
index f3335f2466..3a197d69ae 100644
--- a/test/integration/invalid-custom-routes/test/index.test.js
+++ b/test/integration/invalid-custom-routes/test/index.test.js
@@ -399,7 +399,7 @@ describe('Errors on invalid custom routes', () => {
       getStderr = async () => {
         let stderr = ''
         await launchApp(appDir, await findPort(), {
-          onStderr: msg => {
+          onStderr: (msg) => {
             stderr += msg
           },
         })
diff --git a/test/integration/invalid-href/pages/first.js b/test/integration/invalid-href/pages/first.js
index fc4cd08f45..d136303cea 100644
--- a/test/integration/invalid-href/pages/first.js
+++ b/test/integration/invalid-href/pages/first.js
@@ -10,7 +10,7 @@ export default () => {
   return method ? (
     <a
       id="click-me"
-      onClick={e => {
+      onClick={(e) => {
         e.preventDefault()
         router[method](invalidLink)
       }}
diff --git a/test/integration/invalid-href/pages/second.js b/test/integration/invalid-href/pages/second.js
index d151561719..1dfc0d03e1 100644
--- a/test/integration/invalid-href/pages/second.js
+++ b/test/integration/invalid-href/pages/second.js
@@ -10,7 +10,7 @@ export default () => {
   return method ? (
     <a
       id="click-me"
-      onClick={e => {
+      onClick={(e) => {
         e.preventDefault()
         router[method](invalidLink)
       }}
diff --git a/test/integration/invalid-href/test/index.test.js b/test/integration/invalid-href/test/index.test.js
index 746beb3dd3..07f5bf7821 100644
--- a/test/integration/invalid-href/test/index.test.js
+++ b/test/integration/invalid-href/test/index.test.js
@@ -52,7 +52,7 @@ const showsError = async (
     await waitFor(2000)
     const warnLogs = await browser.eval('window.warnLogs')
     console.log(warnLogs)
-    expect(warnLogs.some(log => log.match(regex))).toBe(true)
+    expect(warnLogs.some((log) => log.match(regex))).toBe(true)
   } else {
     expect(await hasRedbox(browser)).toBe(true)
     const errorContent = await getRedboxHeader(browser)
@@ -181,7 +181,7 @@ describe('Invalid hrefs', () => {
       await waitFor(500)
       const errors = await browser.eval('window.caughtErrors')
       expect(
-        errors.find(err =>
+        errors.find((err) =>
           err.includes(
             'The provided `as` value (/blog/post-1) is incompatible with the `href` value (/[post]). Read more: https://err.sh/zeit/next.js/incompatible-href-as'
           )
diff --git a/test/integration/invalid-multi-match/test/index.test.js b/test/integration/invalid-multi-match/test/index.test.js
index 72f9df7400..56c57da46c 100644
--- a/test/integration/invalid-multi-match/test/index.test.js
+++ b/test/integration/invalid-multi-match/test/index.test.js
@@ -32,7 +32,7 @@ describe('Custom routes invalid multi-match', () => {
     beforeAll(async () => {
       appPort = await findPort()
       app = await launchApp(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
@@ -46,7 +46,7 @@ describe('Custom routes invalid multi-match', () => {
       await nextBuild(appDir)
       appPort = await findPort()
       app = await nextStart(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
diff --git a/test/integration/link-ref/pages/child-ref-func.js b/test/integration/link-ref/pages/child-ref-func.js
index dafbdbe6e9..7588a1ff16 100644
--- a/test/integration/link-ref/pages/child-ref-func.js
+++ b/test/integration/link-ref/pages/child-ref-func.js
@@ -13,7 +13,7 @@ export default () => {
   return (
     <Link href="/">
       <a
-        ref={el => {
+        ref={(el) => {
           myRef.current = el
         }}
       >
diff --git a/test/integration/link-ref/test/index.test.js b/test/integration/link-ref/test/index.test.js
index a8d3e275eb..0251c868f9 100644
--- a/test/integration/link-ref/test/index.test.js
+++ b/test/integration/link-ref/test/index.test.js
@@ -16,7 +16,7 @@ let app
 let appPort
 const appDir = join(__dirname, '..')
 
-const noError = async pathname => {
+const noError = async (pathname) => {
   const browser = await webdriver(appPort, '/')
   await browser.eval(`(function() {
     window.caughtErrors = []
@@ -33,7 +33,7 @@ const noError = async pathname => {
   await browser.close()
 }
 
-const didPrefetch = async pathname => {
+const didPrefetch = async (pathname) => {
   const browser = await webdriver(appPort, pathname)
   const links = await browser.elementsByCss('link[rel=prefetch]')
   let found = false
diff --git a/test/integration/modern-mode/test/index.test.js b/test/integration/modern-mode/test/index.test.js
index a11e8e2a01..f76778bd3c 100644
--- a/test/integration/modern-mode/test/index.test.js
+++ b/test/integration/modern-mode/test/index.test.js
@@ -44,16 +44,16 @@ describe('Modern Mode', () => {
     const buildFiles = [
       ...readdirSync(join(appDir, '.next/static', buildId, 'pages')),
       ...readdirSync(join(appDir, '.next/static/runtime')).map(
-        file => file.replace(/-\w+\./, '.') // remove hash
+        (file) => file.replace(/-\w+\./, '.') // remove hash
       ),
       ...readdirSync(join(appDir, '.next/static/chunks')).map(
-        file => file.replace(/\.\w+\./, '.') // remove hash
+        (file) => file.replace(/\.\w+\./, '.') // remove hash
       ),
     ]
 
     console.log(`Client files: ${buildFiles.join(', ')}`)
 
-    expectedFiles.forEach(file => {
+    expectedFiles.forEach((file) => {
       expect(buildFiles).toContain(`${file}.js`)
       expect(buildFiles).toContain(`${file}.module.js`)
     })
diff --git a/test/integration/next-plugins/test/index.test.js b/test/integration/next-plugins/test/index.test.js
index 4d9870280c..120abed064 100644
--- a/test/integration/next-plugins/test/index.test.js
+++ b/test/integration/next-plugins/test/index.test.js
@@ -36,7 +36,7 @@ function runTests() {
   it('should apply headTags from plugin correctly', async () => {
     const html = await renderViaHTTP(appPort, '/')
     const $ = cheerio.load(html)
-    const found = Array.from($('head').children()).find(el => {
+    const found = Array.from($('head').children()).find((el) => {
       return (el.attribs.src || '').match(/googletagmanager.*?my-tracking-id/)
     })
     expect(found).toBeTruthy()
@@ -46,7 +46,7 @@ function runTests() {
     const html = await renderViaHTTP(appPort, '/')
     const $ = cheerio.load(html)
     const found = Array.from($('body').children()).find(
-      el =>
+      (el) =>
         el.type === 'script' &&
         el.children[0] &&
         el.children[0].data.includes('console.log')
diff --git a/test/integration/non-standard-node-env-warning/server.js b/test/integration/non-standard-node-env-warning/server.js
index b36da3f5c9..4b32085cc2 100644
--- a/test/integration/non-standard-node-env-warning/server.js
+++ b/test/integration/non-standard-node-env-warning/server.js
@@ -13,7 +13,7 @@ app.prepare().then(() => {
     handleNextRequests(req, res)
   })
 
-  server.listen(port, err => {
+  server.listen(port, (err) => {
     if (err) {
       throw err
     }
diff --git a/test/integration/ondemand/test/index.test.js b/test/integration/ondemand/test/index.test.js
index 966a8df2be..e1ff51be3e 100644
--- a/test/integration/ondemand/test/index.test.js
+++ b/test/integration/ondemand/test/index.test.js
@@ -17,7 +17,7 @@ import {
 
 const context = {}
 
-const doPing = page => {
+const doPing = (page) => {
   const controller = new AbortController()
   const signal = controller.signal
   return fetchViaHTTP(
@@ -25,8 +25,8 @@ const doPing = page => {
     '/_next/webpack-hmr',
     { page },
     { signal }
-  ).then(res => {
-    res.body.on('data', chunk => {
+  ).then((res) => {
+    res.body.on('data', (chunk) => {
       try {
         const payload = JSON.parse(chunk.toString().split('data:')[1])
         if (payload.success || payload.invalid) {
diff --git a/test/integration/polyfills/pages/fetch.js b/test/integration/polyfills/pages/fetch.js
index a3a7ed7000..84b0409893 100644
--- a/test/integration/polyfills/pages/fetch.js
+++ b/test/integration/polyfills/pages/fetch.js
@@ -2,7 +2,7 @@ import { useState, useEffect } from 'react'
 import unfetchImp from 'unfetch'
 import isomorphicUnfetchImp from 'isomorphic-unfetch'
 
-const testWhatwgFetchMethods = whatWgFetch => {
+const testWhatwgFetchMethods = (whatWgFetch) => {
   return (
     whatWgFetch.Headers.name === 'Headers' &&
     whatWgFetch.Request.name === 'Request' &&
@@ -18,10 +18,10 @@ const testFetchImports = async () => {
 
   let areImportsMatching =
     [whatwgFetchImp.fetch, whatwgFetchReq.fetch].every(
-      lib => lib.name === 'fetch'
+      (lib) => lib.name === 'fetch'
     ) &&
     [unfetchImp, unfetchReq, isomorphicUnfetchImp, isomorphicUnfetchReq].every(
-      lib => lib.name === 'bound fetch'
+      (lib) => lib.name === 'bound fetch'
     )
 
   return areImportsMatching &&
@@ -35,7 +35,7 @@ const Page = () => {
   const [testStatus, setTestStatus] = useState('computing')
 
   useEffect(() => {
-    testFetchImports().then(status => {
+    testFetchImports().then((status) => {
       console.log(status)
       setTestStatus(status)
     })
diff --git a/test/integration/preload-viewport/test/index.test.js b/test/integration/preload-viewport/test/index.test.js
index 51aa1d562a..cbbceffb74 100644
--- a/test/integration/preload-viewport/test/index.test.js
+++ b/test/integration/preload-viewport/test/index.test.js
@@ -212,7 +212,7 @@ describe('Prefetching Links in viewport', () => {
     expect(hrefs).toEqual([...new Set(hrefs)])
 
     // Verify encoding
-    expect(hrefs.some(e => e.includes(`%5Bhello%5D.js`))).toBe(true)
+    expect(hrefs.some((e) => e.includes(`%5Bhello%5D.js`))).toBe(true)
   })
 
   it('should not add an another observer for a prefetched page', async () => {
@@ -279,7 +279,7 @@ describe('Prefetching Links in viewport', () => {
     }
     hrefs.sort()
 
-    expect(hrefs.map(href => parse(href).pathname)).toMatchInlineSnapshot(`
+    expect(hrefs.map((href) => parse(href).pathname)).toMatchInlineSnapshot(`
       Array [
         "/_next/data/test-build/ssg/basic.json",
         "/_next/data/test-build/ssg/catch-all/foo.json",
@@ -307,7 +307,7 @@ describe('Prefetching Links in viewport', () => {
     }
     hrefs.sort()
 
-    expect(hrefs.map(href => parse(href).pathname)).toMatchInlineSnapshot(`
+    expect(hrefs.map((href) => parse(href).pathname)).toMatchInlineSnapshot(`
       Array [
         "/_next/data/test-build/ssg/catch-all/foo.json",
         "/_next/data/test-build/ssg/catch-all/foo/bar.json",
diff --git a/test/integration/prerender-no-revalidate/test/index.test.js b/test/integration/prerender-no-revalidate/test/index.test.js
index 43af0afed2..abe6662a98 100644
--- a/test/integration/prerender-no-revalidate/test/index.test.js
+++ b/test/integration/prerender-no-revalidate/test/index.test.js
@@ -91,7 +91,7 @@ describe('SSG Prerender No Revalidate', () => {
       appPort = await findPort()
       stderr = ''
       app = await nextStart(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
@@ -113,7 +113,7 @@ describe('SSG Prerender No Revalidate', () => {
       appPort = await findPort()
       stderr = ''
       app = await nextStart(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
diff --git a/test/integration/prerender-preview/pages/index.js b/test/integration/prerender-preview/pages/index.js
index 26d417d3b2..4128f5fc9f 100644
--- a/test/integration/prerender-preview/pages/index.js
+++ b/test/integration/prerender-preview/pages/index.js
@@ -8,7 +8,7 @@ export function getStaticProps({ preview, previewData }) {
   }
 }
 
-export default function({ hasProps, preview, previewData }) {
+export default function ({ hasProps, preview, previewData }) {
   if (!hasProps) {
     return <pre id="props-pre">Has No Props</pre>
   }
diff --git a/test/integration/prerender-preview/pages/to-index.js b/test/integration/prerender-preview/pages/to-index.js
index 008f905005..306ead7496 100644
--- a/test/integration/prerender-preview/pages/to-index.js
+++ b/test/integration/prerender-preview/pages/to-index.js
@@ -4,7 +4,7 @@ export function getStaticProps() {
   return { props: {} }
 }
 
-export default function() {
+export default function () {
   return (
     <main>
       <Link href="/">
diff --git a/test/integration/prerender-preview/test/index.test.js b/test/integration/prerender-preview/test/index.test.js
index 05ee89e204..f85c7a1d5d 100644
--- a/test/integration/prerender-preview/test/index.test.js
+++ b/test/integration/prerender-preview/test/index.test.js
@@ -77,7 +77,7 @@ function runTests(startServer = nextStart) {
     const originalCookies = res.headers.get('set-cookie').split(',')
     const cookies = originalCookies.map(cookie.parse)
 
-    expect(originalCookies.every(c => c.includes('; Secure;'))).toBe(true)
+    expect(originalCookies.every((c) => c.includes('; Secure;'))).toBe(true)
 
     expect(cookies.length).toBe(2)
     expect(cookies[0]).toMatchObject({ Path: '/', SameSite: 'None' })
@@ -103,7 +103,7 @@ function runTests(startServer = nextStart) {
     const originalCookies = res.headers.get('set-cookie').split(',')
     const cookies = originalCookies.map(cookie.parse)
 
-    expect(originalCookies.every(c => c.includes('; Secure;'))).toBe(true)
+    expect(originalCookies.every((c) => c.includes('; Secure;'))).toBe(true)
 
     expect(cookies.length).toBe(2)
     expect(cookies[0]).toMatchObject({ Path: '/', SameSite: 'None' })
@@ -214,10 +214,7 @@ describe('Prerender Preview Mode', () => {
       const res = await fetchViaHTTP(appPort, '/api/preview', { lets: 'goooo' })
       expect(res.status).toBe(200)
 
-      const cookies = res.headers
-        .get('set-cookie')
-        .split(',')
-        .map(cookie.parse)
+      const cookies = res.headers.get('set-cookie').split(',').map(cookie.parse)
 
       expect(cookies.length).toBe(2)
       previewCookieString =
diff --git a/test/integration/prerender/pages/blog/[post]/index.js b/test/integration/prerender/pages/blog/[post]/index.js
index d14a03d8af..0c9f829bca 100644
--- a/test/integration/prerender/pages/blog/[post]/index.js
+++ b/test/integration/prerender/pages/blog/[post]/index.js
@@ -21,7 +21,7 @@ let counter = 0
 
 export async function getStaticProps({ params }) {
   if (params.post === 'post-10') {
-    await new Promise(resolve => {
+    await new Promise((resolve) => {
       setTimeout(() => resolve(), 1000)
     })
   }
diff --git a/test/integration/prerender/pages/catchall-explicit/[...slug].js b/test/integration/prerender/pages/catchall-explicit/[...slug].js
index 419cd89c33..bcdb9c0743 100644
--- a/test/integration/prerender/pages/catchall-explicit/[...slug].js
+++ b/test/integration/prerender/pages/catchall-explicit/[...slug].js
@@ -1,6 +1,6 @@
 export async function getStaticProps({ params: { slug } }) {
   if (slug[0] === 'delayby3s') {
-    await new Promise(resolve => setTimeout(resolve, 3000))
+    await new Promise((resolve) => setTimeout(resolve, 3000))
   }
 
   return {
diff --git a/test/integration/prerender/pages/catchall/[...slug].js b/test/integration/prerender/pages/catchall/[...slug].js
index 57bf14e3b3..b11dbf5ce8 100644
--- a/test/integration/prerender/pages/catchall/[...slug].js
+++ b/test/integration/prerender/pages/catchall/[...slug].js
@@ -2,7 +2,7 @@ import { useRouter } from 'next/router'
 
 export async function getStaticProps({ params: { slug } }) {
   if (slug[0] === 'delayby3s') {
-    await new Promise(resolve => setTimeout(resolve, 3000))
+    await new Promise((resolve) => setTimeout(resolve, 3000))
   }
 
   return {
diff --git a/test/integration/prerender/test/index.test.js b/test/integration/prerender/test/index.test.js
index 32d8764f6c..2ef64b47d5 100644
--- a/test/integration/prerender/test/index.test.js
+++ b/test/integration/prerender/test/index.test.js
@@ -171,7 +171,7 @@ const navigateTest = (dev = false) => {
 
     await waitFor(2500)
 
-    await Promise.all(toBuild.map(pg => renderViaHTTP(appPort, pg)))
+    await Promise.all(toBuild.map((pg) => renderViaHTTP(appPort, pg)))
 
     const browser = await webdriver(appPort, '/')
     let text = await browser.elementByCss('p').text()
@@ -416,11 +416,7 @@ const runTests = (dev = false, looseMode = false) => {
     const $ = cheerio.load(html)
 
     expect(
-      JSON.parse(
-        cheerio
-          .load(html)('#__NEXT_DATA__')
-          .text()
-      ).isFallback
+      JSON.parse(cheerio.load(html)('#__NEXT_DATA__').text()).isFallback
     ).toBe(false)
     expect($('#catchall').text()).toMatch(/Hi.*?another value/)
   })
@@ -471,11 +467,7 @@ const runTests = (dev = false, looseMode = false) => {
     const $ = cheerio.load(html)
 
     expect(
-      JSON.parse(
-        cheerio
-          .load(html)('#__NEXT_DATA__')
-          .text()
-      ).isFallback
+      JSON.parse(cheerio.load(html)('#__NEXT_DATA__').text()).isFallback
     ).toBe(false)
     expect($('#catchall').text()).toMatch(/Hi.*?another value/)
   })
@@ -485,11 +477,7 @@ const runTests = (dev = false, looseMode = false) => {
     const $ = cheerio.load(html)
 
     expect(
-      JSON.parse(
-        cheerio
-          .load(html)('#__NEXT_DATA__')
-          .text()
-      ).isFallback
+      JSON.parse(cheerio.load(html)('#__NEXT_DATA__').text()).isFallback
     ).toBe(false)
     expect($('#catchall').text()).toMatch(/Hi.*?second/)
   })
@@ -879,7 +867,7 @@ const runTests = (dev = false, looseMode = false) => {
       )
       const escapedBuildId = escapeRegex(buildId)
 
-      Object.keys(manifest.dynamicRoutes).forEach(key => {
+      Object.keys(manifest.dynamicRoutes).forEach((key) => {
         const item = manifest.dynamicRoutes[key]
 
         if (item.dataRouteRegex) {
@@ -1074,7 +1062,7 @@ describe('SSG Prerender', () => {
       )
       appPort = await findPort()
       app = await launchApp(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
@@ -1161,7 +1149,7 @@ describe('SSG Prerender', () => {
       stderr = ''
       appPort = await findPort()
       app = await nextStart(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
@@ -1274,7 +1262,7 @@ describe('SSG Prerender', () => {
       stderr = ''
       appPort = await findPort()
       app = await nextStart(appDir, appPort, {
-        onStderr: msg => {
+        onStderr: (msg) => {
           stderr += msg
         },
       })
diff --git a/test/integration/process-env-stub/test/index.test.js b/test/integration/process-env-stub/test/index.test.js
index acdd4cd694..ae9d114692 100644
--- a/test/integration/process-env-stub/test/index.test.js
+++ b/test/integration/process-env-stub/test/index.test.js
@@ -18,7 +18,7 @@ let app
 let stderr
 let appPort
 
-const buildWarning = prop =>
+const buildWarning = (prop) =>
   `An environment variable (${prop}) that was not provided in the environment was accessed`
 
 const checkMissing = async (pathname, prop, shouldWarn = false) => {
@@ -49,7 +49,7 @@ const checkMissingClient = async (pathname, prop, shouldWarn = false) => {
 
   const logs = await browser.eval(`window.warnLogs`)
   const warning = buildWarning(prop)
-  const hasWarn = logs.some(log => log.includes(warning))
+  const hasWarn = logs.some((log) => log.includes(warning))
 
   expect(hasWarn).toBe(shouldWarn)
   await browser.close()
diff --git a/test/integration/production-browser-sourcemaps/test/index.test.js b/test/integration/production-browser-sourcemaps/test/index.test.js
index b10a79c4a1..dcf1be2f10 100644
--- a/test/integration/production-browser-sourcemaps/test/index.test.js
+++ b/test/integration/production-browser-sourcemaps/test/index.test.js
@@ -17,10 +17,10 @@ function runTests() {
       /.*/
     )
     const jsFiles = browserFiles.filter(
-      file => file.endsWith('.js') && file.includes('/pages/')
+      (file) => file.endsWith('.js') && file.includes('/pages/')
     )
 
-    jsFiles.forEach(file => {
+    jsFiles.forEach((file) => {
       expect(browserFiles.includes(`${file}.map`)).toBe(true)
     })
   })
diff --git a/test/integration/production/test/index.test.js b/test/integration/production/test/index.test.js
index f724f7eb16..f2171e4564 100644
--- a/test/integration/production/test/index.test.js
+++ b/test/integration/production/test/index.test.js
@@ -218,15 +218,15 @@ describe('Production Usage', () => {
       )
       expect(mediaStaticAssets.length).toBeGreaterThanOrEqual(1)
       expect(mediaStaticAssets[0]).toMatch(/[\\/]media[\\/]/)
-      ;[...cssStaticAssets, ...mediaStaticAssets].forEach(asset => {
+      ;[...cssStaticAssets, ...mediaStaticAssets].forEach((asset) => {
         resources.add(`${url}static${asset.replace(/\\+/g, '/')}`)
       })
 
       const responses = await Promise.all(
-        [...resources].map(resource => fetch(resource))
+        [...resources].map((resource) => fetch(resource))
       )
 
-      responses.forEach(res => {
+      responses.forEach((res) => {
         try {
           expect(res.headers.get('Cache-Control')).toBe(
             'public, max-age=31536000, immutable'
@@ -358,18 +358,12 @@ describe('Production Usage', () => {
     let id = await browser.elementByCss('#q0').text()
     expect(id).toBe('0')
 
-    await browser
-      .elementByCss('#first')
-      .click()
-      .waitForElementByCss('#q1')
+    await browser.elementByCss('#first').click().waitForElementByCss('#q1')
 
     id = await browser.elementByCss('#q1').text()
     expect(id).toBe('1')
 
-    await browser
-      .elementByCss('#second')
-      .click()
-      .waitForElementByCss('#q2')
+    await browser.elementByCss('#second').click().waitForElementByCss('#q2')
 
     id = await browser.elementByCss('#q2').text()
     expect(id).toBe('2')
@@ -570,7 +564,7 @@ describe('Production Usage', () => {
         await waitFor(3000)
         const browserLogs = await browser.log('browser')
         let foundLog = false
-        browserLogs.forEach(log => {
+        browserLogs.forEach((log) => {
           if (
             log.message.match(/\/no-such-page\.js - Failed to load resource/)
           ) {
@@ -662,7 +656,7 @@ describe('Production Usage', () => {
       browser = await webdriver(appPort, '/development-logs')
       const browserLogs = await browser.log('browser')
       let found = false
-      browserLogs.forEach(log => {
+      browserLogs.forEach((log) => {
         if (log.message.includes('Next.js auto-prefetches automatically')) {
           found = true
         }
@@ -707,7 +701,7 @@ describe('Production Usage', () => {
         'routeChange',
       ]
 
-      allPerfMarks.forEach(name =>
+      allPerfMarks.forEach((name) =>
         expect(currentPerfMarks).not.toContainEqual(
           expect.objectContaining({ name })
         )
diff --git a/test/integration/production/test/process-env.js b/test/integration/production/test/process-env.js
index 7c25c247fc..0ff038cc6f 100644
--- a/test/integration/production/test/process-env.js
+++ b/test/integration/production/test/process-env.js
@@ -3,10 +3,10 @@ import webdriver from 'next-webdriver'
 import { promises } from 'fs'
 import { join } from 'path'
 
-const readNextBuildFile = relativePath =>
+const readNextBuildFile = (relativePath) =>
   promises.readFile(join(__dirname, '../.next', relativePath), 'utf8')
 
-export default context => {
+export default (context) => {
   describe('process.env', () => {
     it('should set process.env.NODE_ENV in production', async () => {
       const browser = await webdriver(context.appPort, '/process-env')
diff --git a/test/integration/production/test/security.js b/test/integration/production/test/security.js
index a7a0cd60ee..f3766956c4 100644
--- a/test/integration/production/test/security.js
+++ b/test/integration/production/test/security.js
@@ -24,7 +24,7 @@ async function checkInjected(browser) {
   }
 }
 
-module.exports = context => {
+module.exports = (context) => {
   describe('With Security Related Issues', () => {
     it('should only access files inside .next directory', async () => {
       const buildId = readFileSync(join(__dirname, '../.next/BUILD_ID'), 'utf8')
@@ -80,7 +80,7 @@ module.exports = context => {
       }
 
       const homeDir = homedir()
-      buildFiles.forEach(buildFile => {
+      buildFiles.forEach((buildFile) => {
         const content = readFileSync(join(readPath, buildFile), 'utf8')
         if (content.includes(homeDir)) {
           throw new Error(
diff --git a/test/integration/route-load-cancel/pages/index.js b/test/integration/route-load-cancel/pages/index.js
index cbbc681310..b9b2e53538 100644
--- a/test/integration/route-load-cancel/pages/index.js
+++ b/test/integration/route-load-cancel/pages/index.js
@@ -5,7 +5,7 @@ import React, { useEffect } from 'react'
 export default () => {
   const router = useRouter()
   useEffect(() => {
-    router.events.on('routeChangeError', err => {
+    router.events.on('routeChangeError', (err) => {
       if (err.cancelled) {
         window.routeCancelled = 'yes'
       }
diff --git a/test/integration/route-load-cancel/pages/page1.js b/test/integration/route-load-cancel/pages/page1.js
index 89eddb2ee8..9813e006c1 100644
--- a/test/integration/route-load-cancel/pages/page1.js
+++ b/test/integration/route-load-cancel/pages/page1.js
@@ -3,7 +3,7 @@ function Page1() {
 }
 
 Page1.getInitialProps = async function getInitialProps() {
-  await new Promise(resolve => setTimeout(resolve, 5000))
+  await new Promise((resolve) => setTimeout(resolve, 5000))
   return {}
 }
 
diff --git a/test/integration/scss-fixtures/with-tailwindcss-and-purgecss/postcss.config.js b/test/integration/scss-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
index b39d3d7ff9..2f75132b35 100644
--- a/test/integration/scss-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
+++ b/test/integration/scss-fixtures/with-tailwindcss-and-purgecss/postcss.config.js
@@ -6,7 +6,7 @@ module.exports = {
       '@fullhuman/postcss-purgecss',
       {
         content: [path.join(__dirname, './pages/**/*.{js,jsx,ts,tsx}')],
-        defaultExtractor: content => content.match(/[A-Za-z0-9-_:/]+/g) || [],
+        defaultExtractor: (content) => content.match(/[A-Za-z0-9-_:/]+/g) || [],
       },
     ],
   ],
diff --git a/test/integration/scss-modules/test/index.test.js b/test/integration/scss-modules/test/index.test.js
index 75d1e609de..e73c4d902e 100644
--- a/test/integration/scss-modules/test/index.test.js
+++ b/test/integration/scss-modules/test/index.test.js
@@ -47,7 +47,7 @@ describe('Basic SCSS Module Support', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -103,7 +103,7 @@ describe('3rd Party CSS Module Support', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -319,7 +319,7 @@ describe('Valid CSS Module Usage from within node_modules', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -372,7 +372,7 @@ describe('Valid Nested CSS Module Usage from within node_modules', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -405,7 +405,7 @@ describe('CSS Module Composes Usage (Basic)', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -438,7 +438,7 @@ describe('CSS Module Composes Usage (External)', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -476,7 +476,7 @@ describe('Dynamic Route CSS Module Usage', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -534,7 +534,7 @@ describe('Catch-all Route CSS Module Usage', () => {
     const cssFolder = join(appDir, '.next/static/css')
 
     const files = await readdir(cssFolder)
-    const cssFiles = files.filter(f => /\.css$/.test(f))
+    const cssFiles = files.filter((f) => /\.css$/.test(f))
 
     expect(cssFiles.length).toBe(1)
     const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
diff --git a/test/integration/scss/test/index.test.js b/test/integration/scss/test/index.test.js
index 85ec031e58..fb47827bc1 100644
--- a/test/integration/scss/test/index.test.js
+++ b/test/integration/scss/test/index.test.js
@@ -69,7 +69,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       expect(await readFile(join(cssFolder, cssFiles[0]), 'utf8')).toContain(
@@ -97,7 +97,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       expect(await readFile(join(cssFolder, cssFiles[0]), 'utf8')).toContain(
@@ -125,7 +125,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       expect(await readFile(join(cssFolder, cssFiles[0]), 'utf8')).toContain(
@@ -153,7 +153,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -182,7 +182,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -213,7 +213,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -231,7 +231,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
       const cssMapContent = (
@@ -281,7 +281,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -607,7 +607,7 @@ describe('SCSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -619,11 +619,8 @@ describe('SCSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -656,7 +653,7 @@ describe('SCSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -668,11 +665,8 @@ describe('SCSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -705,7 +699,7 @@ describe('SCSS Support', () => {
       const mediaFolder = join(appDir, '.next/static/media')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -717,11 +711,8 @@ describe('SCSS Support', () => {
       expect(mediaFiles.length).toBe(3)
       expect(
         mediaFiles
-          .map(fileName =>
-            /^(.+?)\..{32}\.(.+?)$/
-              .exec(fileName)
-              .slice(1)
-              .join('.')
+          .map((fileName) =>
+            /^(.+?)\..{32}\.(.+?)$/.exec(fileName).slice(1).join('.')
           )
           .sort()
       ).toMatchInlineSnapshot(`
@@ -753,7 +744,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -780,7 +771,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -898,7 +889,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -914,7 +905,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
     })
@@ -939,7 +930,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssFiles = files.filter(f => /\.css$/.test(f))
+      const cssFiles = files.filter((f) => /\.css$/.test(f))
 
       expect(cssFiles.length).toBe(1)
       const cssContent = await readFile(join(cssFolder, cssFiles[0]), 'utf8')
@@ -956,7 +947,7 @@ describe('SCSS Support', () => {
       const cssFolder = join(appDir, '.next/static/css')
 
       const files = await readdir(cssFolder)
-      const cssMapFiles = files.filter(f => /\.css\.map$/.test(f))
+      const cssMapFiles = files.filter((f) => /\.css\.map$/.test(f))
 
       expect(cssMapFiles.length).toBe(1)
     })
diff --git a/test/integration/serverless/test/index.test.js b/test/integration/serverless/test/index.test.js
index 602dbe449a..93731bb4e1 100644
--- a/test/integration/serverless/test/index.test.js
+++ b/test/integration/serverless/test/index.test.js
@@ -31,7 +31,7 @@ describe('Serverless', () => {
     await nextBuild(appDir)
     appPort = await findPort()
     app = await nextStart(appDir, appPort, {
-      onStderr: msg => {
+      onStderr: (msg) => {
         stderr += msg || ''
       },
     })
@@ -259,7 +259,7 @@ describe('Serverless', () => {
           1: encodeURIComponent(paramRaw),
         }),
       },
-    }).then(res => res.text())
+    }).then((res) => res.text())
     const $ = cheerio.load(html)
     const data = JSON.parse($('#__NEXT_DATA__').html())
 
@@ -272,10 +272,10 @@ describe('Serverless', () => {
     const html = await fetchViaHTTP(appPort, `/catchall/[...slug]`, '', {
       headers: {
         'x-now-route-matches': qs.stringify({
-          1: paramRaw.map(e => encodeURIComponent(e)).join('/'),
+          1: paramRaw.map((e) => encodeURIComponent(e)).join('/'),
         }),
       },
-    }).then(res => res.text())
+    }).then((res) => res.text())
     const $ = cheerio.load(html)
     const data = JSON.parse($('#__NEXT_DATA__').html())
 
diff --git a/test/integration/size-limit/test/index.test.js b/test/integration/size-limit/test/index.test.js
index 6944d05f2b..4be1dc6531 100644
--- a/test/integration/size-limit/test/index.test.js
+++ b/test/integration/size-limit/test/index.test.js
@@ -13,8 +13,8 @@ let baseResponseSize
 
 function getResponseSizes(resourceUrls) {
   return Promise.all(
-    resourceUrls.map(async url => {
-      const context = await fetch(url).then(res => res.text())
+    resourceUrls.map(async (url) => {
+      const context = await fetch(url).then((res) => res.text())
       return {
         url,
         bytes: context.length,
@@ -57,7 +57,7 @@ describe('Production response size', () => {
     scriptsUrls = $('script[src]')
       .map((i, el) => $(el).attr('src'))
       .get()
-      .map(path => `${baseUrl}${path}`)
+      .map((path) => `${baseUrl}${path}`)
   })
 
   afterAll(async () => {
@@ -69,13 +69,13 @@ describe('Production response size', () => {
     const responseSizes = [
       baseResponseSize,
       ...(await getResponseSizes(
-        scriptsUrls.filter(path => !path.endsWith('.module.js'))
+        scriptsUrls.filter((path) => !path.endsWith('.module.js'))
       )),
     ]
     const responseSizesBytes = getResponseSizesBytes(responseSizes)
     console.log(
       `Response Sizes for default:\n${responseSizes
-        .map(obj => ` ${obj.url}: ${obj.bytes} (bytes)`)
+        .map((obj) => ` ${obj.url}: ${obj.bytes} (bytes)`)
         .join('\n')} \nOverall: ${responseSizesBytes} KB`
     )
 
@@ -89,13 +89,13 @@ describe('Production response size', () => {
     const responseSizes = [
       baseResponseSize,
       ...(await getResponseSizes(
-        scriptsUrls.filter(path => path.endsWith('.module.js'))
+        scriptsUrls.filter((path) => path.endsWith('.module.js'))
       )),
     ]
     const responseSizesBytes = getResponseSizesBytes(responseSizes)
     console.log(
       `Response Sizes for modern:\n${responseSizes
-        .map(obj => ` ${obj.url}: ${obj.bytes} (bytes)`)
+        .map((obj) => ` ${obj.url}: ${obj.bytes} (bytes)`)
         .join('\n')} \nOverall: ${responseSizesBytes} bytes`
     )
 
diff --git a/test/integration/src-dir-support/src/pages/on-mount/[post].js b/test/integration/src-dir-support/src/pages/on-mount/[post].js
index 1016ca9f7a..1bb5e3cd4b 100644
--- a/test/integration/src-dir-support/src/pages/on-mount/[post].js
+++ b/test/integration/src-dir-support/src/pages/on-mount/[post].js
@@ -6,7 +6,7 @@ export default () => {
   return (
     <>
       <p>onmpost: {query.post || 'pending'}</p>
-      {Array.from({ length: 500 }, (x, i) => i + 1).map(i => {
+      {Array.from({ length: 500 }, (x, i) => i + 1).map((i) => {
         return (
           <div key={`item-${i}`} id={`item-${i}`}>
             {i}
diff --git a/test/integration/ssr-ctx/pages/index.js b/test/integration/ssr-ctx/pages/index.js
index 714a84b26c..f20eca5d2a 100644
--- a/test/integration/ssr-ctx/pages/index.js
+++ b/test/integration/ssr-ctx/pages/index.js
@@ -6,7 +6,7 @@ const Page = () => {
   return (
     <div>
       <Idk.Provider value="hello world">
-        <Idk.Consumer>{idk => <p>Value: {idk}</p>}</Idk.Consumer>
+        <Idk.Consumer>{(idk) => <p>Value: {idk}</p>}</Idk.Consumer>
       </Idk.Provider>
     </div>
   )
diff --git a/test/integration/telemetry/test/index.test.js b/test/integration/telemetry/test/index.test.js
index ad7899b5fe..07551ce8d4 100644
--- a/test/integration/telemetry/test/index.test.js
+++ b/test/integration/telemetry/test/index.test.js
@@ -340,7 +340,7 @@ describe('Telemetry CLI', () => {
     let port = await findPort()
     let stderr = ''
 
-    const handleStderr = msg => {
+    const handleStderr = (msg) => {
       stderr += msg
     }
     let app = await launchApp(appDir, port, {
diff --git a/test/integration/tsconfig-verifier/test/index.test.js b/test/integration/tsconfig-verifier/test/index.test.js
index c9d79866b8..bca640c4f4 100644
--- a/test/integration/tsconfig-verifier/test/index.test.js
+++ b/test/integration/tsconfig-verifier/test/index.test.js
@@ -46,17 +46,17 @@ describe('Fork ts checker plugin', () => {
     await killApp(app)
 
     await remove(tsConfig)
-    await new Promise(resolve => setTimeout(resolve, 500))
+    await new Promise((resolve) => setTimeout(resolve, 500))
 
     expect(await exists(tsConfig)).toBe(false)
 
     await createFile(tsConfig)
-    await new Promise(resolve => setTimeout(resolve, 500))
+    await new Promise((resolve) => setTimeout(resolve, 500))
 
     expect(await readFile(tsConfig, 'utf8')).toBe('')
 
     await killApp(app)
-    await new Promise(resolve => setTimeout(resolve, 500))
+    await new Promise((resolve) => setTimeout(resolve, 500))
 
     appPort = await findPort()
     app = await launchApp(appDir, appPort)
diff --git a/test/integration/typescript-ignore-errors/test/index.test.js b/test/integration/typescript-ignore-errors/test/index.test.js
index 78014b7aff..59c49f7c6d 100644
--- a/test/integration/typescript-ignore-errors/test/index.test.js
+++ b/test/integration/typescript-ignore-errors/test/index.test.js
@@ -41,8 +41,8 @@ describe('TypeScript with error handling options', () => {
             try {
               const appPort = await findPort()
               app = await launchApp(appDir, appPort, {
-                onStdout: msg => (output += msg),
-                onStderr: msg => (output += msg),
+                onStdout: (msg) => (output += msg),
+                onStderr: (msg) => (output += msg),
               })
               await renderViaHTTP(appPort, '')
 
diff --git a/test/integration/typescript-only-remove-type-imports/UserStatistics.ts b/test/integration/typescript-only-remove-type-imports/UserStatistics.ts
index 8468224a0b..6052d13136 100644
--- a/test/integration/typescript-only-remove-type-imports/UserStatistics.ts
+++ b/test/integration/typescript-only-remove-type-imports/UserStatistics.ts
@@ -1,5 +1,5 @@
-import type { User } from "./User";
+import type { User } from './User'
 
 export function getNewsletterRecipients(users: User[]) {
-  return users.map(u => u.email);
-}
\ No newline at end of file
+  return users.map((u) => u.email)
+}
diff --git a/test/integration/typescript-only-remove-type-imports/pages/index.tsx b/test/integration/typescript-only-remove-type-imports/pages/index.tsx
index 44957f9108..095cd1ebd8 100644
--- a/test/integration/typescript-only-remove-type-imports/pages/index.tsx
+++ b/test/integration/typescript-only-remove-type-imports/pages/index.tsx
@@ -1,30 +1,30 @@
-import type { User } from "../User";
+import type { User } from '../User'
 // eslint-disable-next-line
-import * as UnusedUserStatisticsThatShouldNotBeElided from "../UserStatistics";
+import * as UnusedUserStatisticsThatShouldNotBeElided from '../UserStatistics'
 
 const users: User[] = [
   {
-    id: "a",
-    email: "a@a.de",
-    username: "anton"
+    id: 'a',
+    email: 'a@a.de',
+    username: 'anton',
   },
   {
-    id: "b",
-    email: "b@b.de",
-    username: "berta"
-  }
+    id: 'b',
+    email: 'b@b.de',
+    username: 'berta',
+  },
 ]
 
 function Index() {
   return (
     <ul>
-      {users.map(u => (
+      {users.map((u) => (
         <li key={u.id}>
           {u.username}: {u.email}
         </li>
       ))}
     </ul>
-  );
+  )
 }
 
-export default Index;
\ No newline at end of file
+export default Index
diff --git a/test/integration/typescript-only-remove-type-imports/pages/normal.tsx b/test/integration/typescript-only-remove-type-imports/pages/normal.tsx
index 7e2e3bb8c9..c5f8a31642 100644
--- a/test/integration/typescript-only-remove-type-imports/pages/normal.tsx
+++ b/test/integration/typescript-only-remove-type-imports/pages/normal.tsx
@@ -1 +1 @@
-export default () => "A normal one"
\ No newline at end of file
+export default () => 'A normal one'
diff --git a/test/integration/typescript/test/index.test.js b/test/integration/typescript/test/index.test.js
index 0cb112c2a9..f7facc29fb 100644
--- a/test/integration/typescript/test/index.test.js
+++ b/test/integration/typescript/test/index.test.js
@@ -19,7 +19,7 @@ let appPort
 let app
 let output
 
-const handleOutput = msg => {
+const handleOutput = (msg) => {
   output += msg
 }
 
diff --git a/test/integration/with-router/components/header-nav.js b/test/integration/with-router/components/header-nav.js
index 4e2a2cf78e..35d9f394d3 100644
--- a/test/integration/with-router/components/header-nav.js
+++ b/test/integration/with-router/components/header-nav.js
@@ -36,19 +36,19 @@ class HeaderNav extends React.Component {
     this.props.router.events.off('routeChangeComplete', this.handleRouteChange)
   }
 
-  handleRouteChange = url => {
+  handleRouteChange = (url) => {
     this.setState({
       activeURL: url,
     })
   }
 
-  handleRouteChangeTopLevelRouter = url => {
+  handleRouteChangeTopLevelRouter = (url) => {
     this.setState({
       activeURLTopLevelRouter: url,
     })
   }
 
-  handleRouteChangeTopLevelRouterDeprecatedBehavior = url => {
+  handleRouteChangeTopLevelRouterDeprecatedBehavior = (url) => {
     this.setState({
       activeURLTopLevelRouterDeprecatedBehavior: url,
     })
@@ -57,7 +57,7 @@ class HeaderNav extends React.Component {
   render() {
     return (
       <nav>
-        {Object.keys(pages).map(url => (
+        {Object.keys(pages).map((url) => (
           <Link href={url} key={url} prefetch>
             <a
               className={`${this.state.activeURL === url ? 'active' : ''} ${
diff --git a/test/jest-environment.js b/test/jest-environment.js
index 5e6b56ae23..c254b08206 100644
--- a/test/jest-environment.js
+++ b/test/jest-environment.js
@@ -33,7 +33,7 @@ class CustomEnvironment extends NodeEnvironment {
     const newTabPort = await getPort()
 
     await new Promise((resolve, reject) => {
-      this.server.listen(newTabPort, err => {
+      this.server.listen(newTabPort, (err) => {
         if (err) return reject(err)
         resolve()
       })
@@ -44,7 +44,7 @@ class CustomEnvironment extends NodeEnvironment {
     if (browserName !== 'chrome' && SKIP_LOCAL_SELENIUM_SERVER !== 'true') {
       console.log('Installing selenium server')
       await new Promise((resolve, reject) => {
-        seleniumServer.install(err => {
+        seleniumServer.install((err) => {
           if (err) return reject(err)
           resolve()
         })
diff --git a/test/jest-global-setup.js b/test/jest-global-setup.js
index 4f9d249fa7..f0bcb418de 100644
--- a/test/jest-global-setup.js
+++ b/test/jest-global-setup.js
@@ -12,7 +12,7 @@ if (process.env.BROWSERSTACK) {
 
   globalSetup = () => {
     return new Promise((resolve, reject) => {
-      browserStackLocal.start(localBrowserStackOpts, err => {
+      browserStackLocal.start(localBrowserStackOpts, (err) => {
         if (err) return reject(err)
         console.log('Started BrowserStackLocal', browserStackLocal.isRunning())
         resolve()
diff --git a/test/lib/flat-map-polyfill.js b/test/lib/flat-map-polyfill.js
index e5002d82a7..b9ad706cfe 100644
--- a/test/lib/flat-map-polyfill.js
+++ b/test/lib/flat-map-polyfill.js
@@ -8,7 +8,7 @@ if (!Array.prototype.flat) {
       return depth
         ? Array.prototype.reduce.call(
             this,
-            function(acc, cur) {
+            function (acc, cur) {
               if (Array.isArray(cur)) {
                 acc.push.apply(acc, flat.call(cur, depth - 1))
               } else {
diff --git a/test/lib/next-test-utils.js b/test/lib/next-test-utils.js
index e7a6444436..359f6b0199 100644
--- a/test/lib/next-test-utils.js
+++ b/test/lib/next-test-utils.js
@@ -60,7 +60,7 @@ export function initNextServerScript(
       instance.stderr.removeListener('data', handleStderr)
     })
 
-    instance.on('error', err => {
+    instance.on('error', (err) => {
       reject(err)
     })
   })
@@ -72,7 +72,7 @@ export function renderViaAPI(app, pathname, query) {
 }
 
 export function renderViaHTTP(appPort, pathname, query) {
-  return fetchViaHTTP(appPort, pathname, query).then(res => res.text())
+  return fetchViaHTTP(appPort, pathname, query).then((res) => res.text())
 }
 
 export function fetchViaHTTP(appPort, pathname, query, opts) {
@@ -113,19 +113,19 @@ export function runNextCommand(argv, options = {}) {
 
     let stderrOutput = ''
     if (options.stderr) {
-      instance.stderr.on('data', function(chunk) {
+      instance.stderr.on('data', function (chunk) {
         stderrOutput += chunk
       })
     }
 
     let stdoutOutput = ''
     if (options.stdout) {
-      instance.stdout.on('data', function(chunk) {
+      instance.stdout.on('data', function (chunk) {
         stdoutOutput += chunk
       })
     }
 
-    instance.on('close', code => {
+    instance.on('close', (code) => {
       resolve({
         code,
         stdout: stdoutOutput,
@@ -133,7 +133,7 @@ export function runNextCommand(argv, options = {}) {
       })
     })
 
-    instance.on('error', err => {
+    instance.on('error', (err) => {
       err.stdout = stdoutOutput
       err.stderr = stderrOutput
       reject(err)
@@ -201,7 +201,7 @@ export function runNextCommandDev(argv, stdOut, opts = {}) {
       }
     })
 
-    instance.on('error', err => {
+    instance.on('error', (err) => {
       reject(err)
     })
   })
@@ -243,14 +243,14 @@ export function buildTS(args = [], cwd, env = {}) {
     )
     let output = ''
 
-    const handleData = chunk => {
+    const handleData = (chunk) => {
       output += chunk.toString()
     }
 
     instance.stdout.on('data', handleData)
     instance.stderr.on('data', handleData)
 
-    instance.on('exit', code => {
+    instance.on('exit', (code) => {
       if (code) {
         return reject(new Error('exited with code: ' + code + '\n' + output))
       }
@@ -262,7 +262,7 @@ export function buildTS(args = [], cwd, env = {}) {
 // Kill a launched app
 export async function killApp(instance) {
   await new Promise((resolve, reject) => {
-    treeKill(instance.pid, err => {
+    treeKill(instance.pid, (err) => {
       if (err) {
         if (
           process.platform === 'win32' &&
@@ -306,7 +306,7 @@ export function promiseCall(obj, method, ...args) {
   return new Promise((resolve, reject) => {
     const newArgs = [
       ...args,
-      function(err, res) {
+      function (err, res) {
         if (err) return reject(err)
         resolve(res)
       },
@@ -317,7 +317,7 @@ export function promiseCall(obj, method, ...args) {
 }
 
 export function waitFor(millis) {
-  return new Promise(resolve => setTimeout(resolve, millis))
+  return new Promise((resolve) => setTimeout(resolve, millis))
 }
 
 export async function startStaticServer(dir) {
@@ -414,7 +414,7 @@ export class File {
 export async function evaluate(browser, input) {
   if (typeof input === 'function') {
     const result = await browser.executeScript(input)
-    await new Promise(resolve => setTimeout(resolve, 30))
+    await new Promise((resolve) => setTimeout(resolve, 30))
     return result
   } else {
     throw new Error(`You must pass a function to be evaluated in the browser.`)
@@ -428,7 +428,7 @@ export async function hasRedbox(browser, expected = true) {
       return Boolean(
         [].slice
           .call(document.querySelectorAll('nextjs-portal'))
-          .find(p =>
+          .find((p) =>
             p.shadowRoot.querySelector(
               '#nextjs__container_errors_label, #nextjs__container_build_error_label'
             )
@@ -442,7 +442,7 @@ export async function hasRedbox(browser, expected = true) {
       break
     }
 
-    await new Promise(resolve => setTimeout(resolve, 1000))
+    await new Promise((resolve) => setTimeout(resolve, 1000))
   } while (expected)
   return false
 }
@@ -451,7 +451,7 @@ export async function getRedboxHeader(browser) {
   return evaluate(browser, () => {
     const portal = [].slice
       .call(document.querySelectorAll('nextjs-portal'))
-      .find(p => p.shadowRoot.querySelector('[data-nextjs-dialog-header'))
+      .find((p) => p.shadowRoot.querySelector('[data-nextjs-dialog-header'))
     const root = portal.shadowRoot
     return root.querySelector('[data-nextjs-dialog-header]').innerText
   })
@@ -461,7 +461,7 @@ export async function getRedboxSource(browser) {
   return evaluate(browser, () => {
     const portal = [].slice
       .call(document.querySelectorAll('nextjs-portal'))
-      .find(p =>
+      .find((p) =>
         p.shadowRoot.querySelector(
           '#nextjs__container_errors_label, #nextjs__container_build_error_label'
         )
diff --git a/test/lib/next-webdriver.d.ts b/test/lib/next-webdriver.d.ts
index e83e678083..e366c58c9c 100644
--- a/test/lib/next-webdriver.d.ts
+++ b/test/lib/next-webdriver.d.ts
@@ -21,7 +21,7 @@ interface Chain {
   quit: () => Chain
 }
 
-export default function(
+export default function (
   appPort: number,
   path: string,
   waitHydration?: boolean
diff --git a/test/lib/next-webdriver.js b/test/lib/next-webdriver.js
index 061328769a..e3b8e6ed6c 100644
--- a/test/lib/next-webdriver.js
+++ b/test/lib/next-webdriver.js
@@ -148,7 +148,7 @@ const freshWindow = async () => {
   await newTabLink.click()
 
   allWindows = await browser.getAllWindowHandles()
-  const newWindow = allWindows.find(win => win !== initialWindow)
+  const newWindow = allWindows.find((win) => win !== initialWindow)
   await browser.switchTo().window(newWindow)
 }
 
@@ -175,7 +175,7 @@ export default async (appPort, path, waitHydration = true) => {
   // Wait for application to hydrate
   if (waitHydration) {
     console.log(`\n> Waiting hydration for ${url}\n`)
-    await browser.executeAsyncScript(function() {
+    await browser.executeAsyncScript(function () {
       var callback = arguments[arguments.length - 1]
 
       // if it's not a Next.js app return
@@ -187,7 +187,7 @@ export default async (appPort, path, waitHydration = true) => {
         callback()
       } else {
         var timeout = setTimeout(callback, 10 * 1000)
-        window.__NEXT_HYDRATED_CB = function() {
+        window.__NEXT_HYDRATED_CB = function () {
           clearTimeout(timeout)
           callback()
         }
diff --git a/test/lib/wd-chain.js b/test/lib/wd-chain.js
index 0d402eee57..fc80746418 100644
--- a/test/lib/wd-chain.js
+++ b/test/lib/wd-chain.js
@@ -10,19 +10,19 @@ export default class Chain {
       this.promise = Promise.resolve()
     }
     this.promise = this.promise.then(nextCall)
-    this.then = cb => this.promise.then(cb)
-    this.catch = cb => this.promise.catch(cb)
-    this.finally = cb => this.promise.finally(cb)
+    this.then = (cb) => this.promise.then(cb)
+    this.catch = (cb) => this.promise.catch(cb)
+    this.finally = (cb) => this.promise.finally(cb)
     return this
   }
 
   elementByCss(sel) {
     return this.updateChain(() =>
-      this.browser.findElement(By.css(sel)).then(el => {
+      this.browser.findElement(By.css(sel)).then((el) => {
         el.sel = sel
         el.text = () => el.getText()
-        el.getComputedCss = prop => el.getCssValue(prop)
-        el.type = text => el.sendKeys(text)
+        el.getComputedCss = (prop) => el.getCssValue(prop)
+        el.type = (text) => el.sendKeys(text)
         el.getValue = () =>
           this.browser.executeScript(
             `return document.querySelector('${sel}').value`
@@ -37,7 +37,7 @@ export default class Chain {
   }
 
   getValue() {
-    return this.updateChain(el =>
+    return this.updateChain((el) =>
       this.browser.executeScript(
         `return document.querySelector('${el.sel}').value`
       )
@@ -45,15 +45,15 @@ export default class Chain {
   }
 
   text() {
-    return this.updateChain(el => el.getText())
+    return this.updateChain((el) => el.getText())
   }
 
   type(text) {
-    return this.updateChain(el => el.sendKeys(text))
+    return this.updateChain((el) => el.sendKeys(text))
   }
 
   moveTo() {
-    return this.updateChain(el => {
+    return this.updateChain((el) => {
       return this.browser
         .actions()
         .move({ origin: el })
@@ -63,13 +63,13 @@ export default class Chain {
   }
 
   getComputedCss(prop) {
-    return this.updateChain(el => {
+    return this.updateChain((el) => {
       return el.getCssValue(prop)
     })
   }
 
   getAttribute(attr) {
-    return this.updateChain(el => el.getAttribute(attr))
+    return this.updateChain((el) => el.getAttribute(attr))
   }
 
   hasElementByCssSelector(sel) {
@@ -77,7 +77,7 @@ export default class Chain {
   }
 
   click() {
-    return this.updateChain(el => {
+    return this.updateChain((el) => {
       return el.click().then(() => el)
     })
   }
@@ -100,12 +100,7 @@ export default class Chain {
   }
 
   log(type) {
-    return this.updateChain(() =>
-      this.browser
-        .manage()
-        .logs()
-        .get(type)
-    )
+    return this.updateChain(() => this.browser.manage().logs().get(type))
   }
 
   url() {
diff --git a/test/unit/babel-plugin-next-ssg-transform.test.js b/test/unit/babel-plugin-next-ssg-transform.test.js
index 97f34add42..7acba93216 100644
--- a/test/unit/babel-plugin-next-ssg-transform.test.js
+++ b/test/unit/babel-plugin-next-ssg-transform.test.js
@@ -1,11 +1,7 @@
 /* eslint-env jest */
 import { transform } from '@babel/core'
 
-const trim = s =>
-  s
-    .join('\n')
-    .trim()
-    .replace(/^\s+/gm, '')
+const trim = (s) => s.join('\n').trim().replace(/^\s+/gm, '')
 
 // avoid generating __source annotations in JSX during testing:
 const NODE_ENV = process.env.NODE_ENV
diff --git a/test/unit/is-serializable-props.test.js b/test/unit/is-serializable-props.test.js
index 451090000b..89039e76fa 100644
--- a/test/unit/is-serializable-props.test.js
+++ b/test/unit/is-serializable-props.test.js
@@ -111,7 +111,7 @@ Reason: \`undefined\` cannot be serialized as JSON. Please use \`null\` or omit
 Reason: \`symbol\` cannot be serialized as JSON. Please only return JSON serializable data types."
 `)
 
-    expect(() => isSerializableProps('/', 'test', { toplevel: function() {} }))
+    expect(() => isSerializableProps('/', 'test', { toplevel: function () {} }))
       .toThrowErrorMatchingInlineSnapshot(`
 "Error serializing \`.toplevel\` returned from \`test\` in \\"/\\".
 Reason: \`function\` cannot be serialized as JSON. Please only return JSON serializable data types."
@@ -147,7 +147,7 @@ Reason: \`symbol\` cannot be serialized as JSON. Please only return JSON seriali
 `)
 
     expect(() =>
-      isSerializableProps('/', 'test', { k: { a: [function() {}] } })
+      isSerializableProps('/', 'test', { k: { a: [function () {}] } })
     ).toThrowErrorMatchingInlineSnapshot(`
 "Error serializing \`.k.a[0]\` returned from \`test\` in \\"/\\".
 Reason: \`function\` cannot be serialized as JSON. Please only return JSON serializable data types."
diff --git a/test/unit/mitt.test.js b/test/unit/mitt.test.js
index b77ceaa666..79e3a7bb54 100644
--- a/test/unit/mitt.test.js
+++ b/test/unit/mitt.test.js
@@ -4,7 +4,7 @@ import mitt from 'next/dist/next-server/lib/mitt'
 describe('mitt', () => {
   describe('With listeners', () => {
     it('should listen to a event', () => {
-      return new Promise(resolve => {
+      return new Promise((resolve) => {
         const ev = mitt()
         ev.on('sample', resolve)
         ev.emit('sample')
@@ -30,7 +30,7 @@ describe('mitt', () => {
     it('should listen to multiple events', () => {
       const ev = mitt()
       const data = []
-      const cb = name => {
+      const cb = (name) => {
         data.push(name)
       }
 
diff --git a/test/unit/next-babel.test.js b/test/unit/next-babel.test.js
index f824aa2b0d..a385ea4017 100644
--- a/test/unit/next-babel.test.js
+++ b/test/unit/next-babel.test.js
@@ -1,11 +1,7 @@
 /* eslint-env jest */
 import { transform } from '@babel/core'
 
-const trim = s =>
-  s
-    .join('\n')
-    .trim()
-    .replace(/^\s+/gm, '')
+const trim = (s) => s.join('\n').trim().replace(/^\s+/gm, '')
 
 // avoid generating __source annotations in JSX during testing:
 const NODE_ENV = process.env.NODE_ENV
diff --git a/test/unit/recursive-readdir.test.js b/test/unit/recursive-readdir.test.js
index b96b582c40..ce0c15b54f 100644
--- a/test/unit/recursive-readdir.test.js
+++ b/test/unit/recursive-readdir.test.js
@@ -20,7 +20,7 @@ describe('recursiveReadDir', () => {
       /^[\\/]nav[\\/]products[\\/]product\.js/,
     ]
     expect(
-      result.filter(item => {
+      result.filter((item) => {
         for (const page of pages) {
           if (page.test(item)) {
             return false
diff --git a/yarn.lock b/yarn.lock
index 6ec132ab82..bd9231a4f8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -14560,10 +14560,10 @@ preserve@^0.2.0:
   resolved "https://registry.yarnpkg.com/preserve/-/preserve-0.2.0.tgz#815ed1f6ebc65926f865b310c0713bcb3315ce4b"
   integrity sha1-gV7R9uvGWSb4ZbMQwHE7yzMVzks=
 
-prettier@1.19.1:
-  version "1.19.1"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
-  integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
+prettier@2.0.5:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.0.5.tgz#d6d56282455243f2f92cc1716692c08aa31522d4"
+  integrity sha512-7PtVymN48hGcO4fGjybyBSIWDsLU4H4XlvOHfq91pz9kkGlonzwTfYkaIEwiRg/dAJF9YlbsduBAgtYLi+8cFg==
 
 pretty-bytes@^3.0.0:
   version "3.0.1"