Add support for rendering .css chunks (#4861)

Depends on https://github.com/zeit/next-plugins/pull/228

Failing tests are expected as `@zeit/next-css` has to be updated/released first.

This implements rendering of `.css` chunks. Effectively removing the custom document requirement when adding next-css/sass/less/stylus.

build/webpack.js

@@ -41,7 +41,7 @@ function externalsConfig (dir, isServer) {
       }
 
       // Webpack itself has to be compiled because it doesn't always use module relative paths
-      if (res.match(/node_modules[/\\]webpack/)) {
+      if (res.match(/node_modules[/\\]webpack/) || res.match(/node_modules[/\\]css-loader/)) {
         return callback()
       }
 
@@ -59,7 +59,6 @@ function externalsConfig (dir, isServer) {
 function optimizationConfig ({dir, dev, isServer, totalPages}) {
   if (isServer) {
     return {
-      // runtimeChunk: 'single',
       splitChunks: false,
       minimize: false
     }
@@ -69,7 +68,12 @@ function optimizationConfig ({dir, dev, isServer, totalPages}) {
     runtimeChunk: {
       name: CLIENT_STATIC_FILES_RUNTIME_WEBPACK
     },
-    splitChunks: false
+    splitChunks: {
+      cacheGroups: {
+        default: false,
+        vendors: false
+      }
+    }
   }
 
   if (dev) {
@@ -79,21 +83,14 @@ function optimizationConfig ({dir, dev, isServer, totalPages}) {
   // Only enabled in production
   // This logic will create a commons bundle
   // with modules that are used in 50% of all pages
-  return {
-    ...config,
-    splitChunks: {
-      chunks: 'all',
-      cacheGroups: {
-        default: false,
-        vendors: false,
-        commons: {
-          name: 'commons',
-          chunks: 'all',
-          minChunks: totalPages > 2 ? totalPages * 0.5 : 2
-        }
-      }
-    }
+  config.splitChunks.chunks = 'all'
+  config.splitChunks.cacheGroups.commons = {
+    name: 'commons',
+    chunks: 'all',
+    minChunks: totalPages > 2 ? totalPages * 0.5 : 2
   }
+
+  return config
 }
 
 type BaseConfigContext = {|

build/webpack/plugins/build-manifest-plugin.js

@@ -8,7 +8,7 @@ export default class BuildManifestPlugin {
   apply (compiler: any) {
     compiler.hooks.emit.tapAsync('NextJsBuildManifest', (compilation, callback) => {
       const {chunks} = compilation
-      const assetMap = {pages: {}, css: []}
+      const assetMap = {pages: {}}
 
       const mainJsChunk = chunks.find((c) => c.name === CLIENT_STATIC_FILES_RUNTIME_MAIN)
       const mainJsFiles = mainJsChunk && mainJsChunk.files.length > 0 ? mainJsChunk.files.filter((file) => /\.js$/.test(file)) : []
@@ -35,12 +35,16 @@ export default class BuildManifestPlugin {
           }
 
           for (const file of chunk.files) {
-            // Only `.js` files are added for now. In the future we can also handle other file types.
-            if (/\.map$/.test(file) || /\.hot-update\.js$/.test(file) || !/\.js$/.test(file)) {
+            if (/\.map$/.test(file) || /\.hot-update\.js$/.test(file)) {
               continue
             }
 
-            // These are manually added to _document.js
+            // Only `.js` and `.css` files are added for now. In the future we can also handle other file types.
+            if (!/\.js$/.test(file) && !/\.css$/.test(file)) {
+              continue
+            }
+
+            // The page bundles are manually added to _document.js as they need extra properties
             if (IS_BUNDLED_PAGE_REGEX.exec(file)) {
               continue
             }
@@ -52,35 +56,6 @@ export default class BuildManifestPlugin {
         assetMap.pages[`/${pagePath.replace(/\\/g, '/')}`] = [...filesForEntry, ...mainJsFiles]
       }
 
-      for (const chunk of chunks) {
-        if (!chunk.name || !chunk.files) {
-          continue
-        }
-
-        const files = []
-
-        for (const file of chunk.files) {
-          if (/\.map$/.test(file)) {
-            continue
-          }
-
-          if (/\.hot-update\.js$/.test(file)) {
-            continue
-          }
-
-          if (/\.css$/.exec(file)) {
-            assetMap.css.push(file)
-            continue
-          }
-
-          files.push(file)
-        }
-
-        if (files.length > 0) {
-          assetMap[chunk.name] = files
-        }
-      }
-
       if (typeof assetMap.pages['/index'] !== 'undefined') {
         assetMap.pages['/'] = assetMap.pages['/index']
       }

build/webpack/plugins/nextjs-ssr-module-cache.js

@@ -1,6 +1,7 @@
 import webpack from 'webpack'
 import { RawSource } from 'webpack-sources'
 import { join, relative, dirname } from 'path'
+import {IS_BUNDLED_PAGE_REGEX} from '../../../lib/constants'
 
 const SSR_MODULE_CACHE_FILENAME = 'ssr-module-cache.js'
 
@@ -31,7 +32,14 @@ export default class NextJsSsrImportPlugin {
       compilation.mainTemplate.hooks.localVars.intercept({
         register (tapInfo) {
           if (tapInfo.name === 'MainTemplate') {
+            const originalFn = tapInfo.fn
             tapInfo.fn = (source, chunk) => {
+              // If the chunk is not part of the pages directory we have to keep the original behavior,
+              // otherwise webpack will error out when the file is used before the compilation finishes
+              // this is the case with mini-css-extract-plugin
+              if (!IS_BUNDLED_PAGE_REGEX.exec(chunk.name)) {
+                return originalFn(source, chunk)
+              }
               const pagePath = join(outputPath, dirname(chunk.name))
               const relativePathToBaseDir = relative(pagePath, join(outputPath, SSR_MODULE_CACHE_FILENAME))
               // Make sure even in windows, the path looks like in unix

package.json

@@ -99,7 +99,7 @@
     "unfetch": "3.0.0",
     "url": "0.11.0",
     "uuid": "3.1.0",
-    "webpack": "4.16.1",
+    "webpack": "4.16.3",
     "webpack-dev-middleware": "3.1.3",
     "webpack-hot-middleware": "2.22.2",
     "webpack-sources": "1.1.0",
@@ -112,7 +112,8 @@
     "@taskr/clear": "1.1.0",
     "@taskr/esnext": "1.1.0",
     "@taskr/watch": "1.1.0",
-    "@zeit/next-css": "0.0.7",
+    "@zeit/next-css": "0.2.1-canary.1",
+    "@zeit/next-sass": "0.2.1-canary.1",
     "@zeit/next-typescript": "1.1.0",
     "babel-eslint": "8.2.2",
     "babel-jest": "21.2.0",
@@ -135,6 +136,7 @@
     "mkdirp": "0.5.1",
     "node-fetch": "1.7.3",
     "node-notifier": "5.1.2",
+    "node-sass": "4.9.2",
     "nyc": "11.2.1",
     "react": "16.4.0",
     "react-dom": "16.4.0",

server/document.js

@@ -49,15 +49,41 @@ export class Head extends Component {
       return null
     }
   
-    return files.map((file) => (
-      <link
+    return files.map((file) => {
+      // Only render .js files here
+      if(!/\.js$/.exec(file)) {
+        return null
+      }
+
+      return <link
         key={file}
         nonce={this.props.nonce}
         rel='preload'
         href={`${assetPrefix}/_next/${file}`}
         as='script'
       />
-    ))
+    })
+  }
+
+  getCssLinks () {
+    const { assetPrefix, files } = this.context._documentProps
+    if(!files || files.length === 0) {
+      return null
+    }
+  
+    return files.map((file) => {
+      // Only render .css files here
+      if(!/\.css$/.exec(file)) {
+        return null
+      }
+
+      return <link
+        key={file}
+        nonce={this.props.nonce}
+        rel='stylesheet'
+        href={`${assetPrefix}/_next/${file}`}
+      />
+    })
   }
 
   getPreloadDynamicChunks () {
@@ -85,6 +111,7 @@ export class Head extends Component {
       <link rel='preload' href={`${assetPrefix}/_next/static/${buildId}/pages/_error.js`} as='script' nonce={this.props.nonce} />
       {this.getPreloadDynamicChunks()}
       {this.getPreloadMainLinks()}
+      {this.getCssLinks()}
       {styles || null}
       {this.props.children}
     </head>
@@ -122,14 +149,19 @@ export class NextScript extends Component {
       return null
     }
   
-    return files.map((file) => (
-      <script
+    return files.map((file) => {
+      // Only render .js files here
+      if(!/\.js$/.exec(file)) {
+        return null
+      }
+
+      return <script
         key={file}
         src={`${assetPrefix}/_next/${file}`}
         nonce={this.props.nonce}
         async
       />
-    ))
+    })
   }
 
   getDynamicChunks () {

test/integration/config/components/hello-webpack-css.css

@@ -1,3 +1,3 @@
 .helloWorld {
-  color: red;
+  font-size: 100px;
 }

test/integration/config/components/hello-webpack-css.js

@@ -1,3 +1,4 @@
 import css from './hello-webpack-css.css'
+import sass from './hello-webpack-sass.scss'
 import framework from 'css-framework/framework.css'
-export default () => <div className={`${css.helloWorld} ${framework.frameworkClass}`}>Hello World</div>
+export default () => <div className={`hello-world ${css.helloWorld} ${sass.helloWorldSass} ${framework.frameworkClass}`}>Hello World</div>

test/integration/config/components/hello-webpack-sass.scss

@@ -0,0 +1,5 @@
+$color: yellow;
+
+.helloWorldSass {
+  color: $color;
+}

test/integration/config/next.config.js

@@ -1,7 +1,8 @@
-// const withCSS = require('@zeit/next-css')
+const withCSS = require('@zeit/next-css')
+const withSass = require('@zeit/next-sass')
 const webpack = require('webpack')
-// module.exports = withCSS({
-module.exports = {
+const path = require('path')
+module.exports = withCSS(withSass({
   onDemandEntries: {
     // Make sure entries are not getting disposed.
     maxInactiveAge: 1000 * 60 * 60
@@ -14,6 +15,16 @@ module.exports = {
     staticFolder: '/static'
   },
   webpack (config, {buildId}) {
+    // When next-css is `npm link`ed we have to solve loaders from the project root
+    const nextLocation = path.join(require.resolve('next/package.json'), '../')
+    const nextCssNodeModulesLocation = path.join(
+      require.resolve('@zeit/next-css'),
+      '../../../node_modules'
+    )
+
+    if (nextCssNodeModulesLocation.indexOf(nextLocation) === -1) {
+      config.resolveLoader.modules.push(nextCssNodeModulesLocation)
+    }
     config.plugins.push(
       new webpack.DefinePlugin({
         'process.env.CONFIG_BUILD_ID': JSON.stringify(buildId)
@@ -22,5 +33,4 @@ module.exports = {
 
     return config
   }
-// })
-}
+}))

test/integration/config/node_modules/css-framework/framework.css

@@ -1,3 +1,3 @@
 .frameworkClass {
-  font-size: 100px;
+  background: blue
 }

test/integration/config/test/client.js

@@ -2,6 +2,8 @@
 
 import webdriver from 'next-webdriver'
 import { waitFor } from 'next-test-utils'
+import { readFileSync, writeFileSync } from 'fs'
+import { join } from 'path'
 
 export default (context, render) => {
   describe('Configuration', () => {
@@ -17,5 +19,81 @@ export default (context, render) => {
       expect(serverClientText).toBe('/static')
       browser.close()
     })
+
+    it('should update css styles using hmr', async () => {
+      let browser
+      try {
+        browser = await webdriver(context.appPort, '/webpack-css')
+        const pTag = await browser.elementByCss('.hello-world')
+        const initialFontSize = await pTag.getComputedCss('font-size')
+
+        expect(initialFontSize).toBe('100px')
+
+        const pagePath = join(__dirname, '../', 'components', 'hello-webpack-css.css')
+
+        const originalContent = readFileSync(pagePath, 'utf8')
+        const editedContent = originalContent.replace('100px', '200px')
+
+        // Change the page
+        writeFileSync(pagePath, editedContent, 'utf8')
+
+        // wait for 5 seconds
+        await waitFor(5000)
+
+        try {
+          // Check whether the this page has reloaded or not.
+          const editedPTag = await browser.elementByCss('.hello-world')
+          const editedFontSize = await editedPTag.getComputedCss('font-size')
+
+          expect(editedFontSize).toBe('200px')
+        } finally {
+          // Finally is used so that we revert the content back to the original regardless of the test outcome
+          // restore the about page content.
+          writeFileSync(pagePath, originalContent, 'utf8')
+        }
+      } finally {
+        if (browser) {
+          browser.close()
+        }
+      }
+    })
+
+    it('should update sass styles using hmr', async () => {
+      let browser
+      try {
+        browser = await webdriver(context.appPort, '/webpack-css')
+        const pTag = await browser.elementByCss('.hello-world')
+        const initialFontSize = await pTag.getComputedCss('color')
+
+        expect(initialFontSize).toBe('rgba(255, 255, 0, 1)')
+
+        const pagePath = join(__dirname, '../', 'components', 'hello-webpack-sass.scss')
+
+        const originalContent = readFileSync(pagePath, 'utf8')
+        const editedContent = originalContent.replace('yellow', 'red')
+
+        // Change the page
+        writeFileSync(pagePath, editedContent, 'utf8')
+
+        // wait for 5 seconds
+        await waitFor(5000)
+
+        try {
+          // Check whether the this page has reloaded or not.
+          const editedPTag = await browser.elementByCss('.hello-world')
+          const editedFontSize = await editedPTag.getComputedCss('color')
+
+          expect(editedFontSize).toBe('rgba(255, 0, 0, 1)')
+        } finally {
+          // Finally is used so that we revert the content back to the original regardless of the test outcome
+          // restore the about page content.
+          writeFileSync(pagePath, originalContent, 'utf8')
+        }
+      } finally {
+        if (browser) {
+          browser.close()
+        }
+      }
+    })
   })
 }

test/integration/config/test/index.test.js

@@ -24,8 +24,8 @@ describe('Configuration', () => {
     // pre-build all pages at the start
     await Promise.all([
       renderViaHTTP(context.appPort, '/next-config'),
-      renderViaHTTP(context.appPort, '/build-id')
-      // renderViaHTTP(context.appPort, '/webpack-css')
+      renderViaHTTP(context.appPort, '/build-id'),
+      renderViaHTTP(context.appPort, '/webpack-css')
     ])
   })
   afterAll(() => killApp(context.server))

test/integration/config/test/rendering.js

@@ -9,15 +9,15 @@ export default function ({ app }, suiteName, render, fetch) {
   }
 
   describe(suiteName, () => {
-    // test('renders css imports', async () => {
-    //   const $ = await get$('/webpack-css')
-    //   expect($('._46QtCORzC4BWRnIseSbG-').text() === 'Hello World')
-    // })
+    test('renders css imports', async () => {
+      const $ = await get$('/webpack-css')
+      expect($('._46QtCORzC4BWRnIseSbG-').text() === 'Hello World')
+    })
 
-    // test('renders non-js imports from node_modules', async () => {
-    //   const $ = await get$('/webpack-css')
-    //   expect($('._2pRSkKTPDMGLMnmsEkP__J').text() === 'Hello World')
-    // })
+    test('renders non-js imports from node_modules', async () => {
+      const $ = await get$('/webpack-css')
+      expect($('._2pRSkKTPDMGLMnmsEkP__J').text() === 'Hello World')
+    })
 
     test('renders server config on the server only', async () => {
       const $ = await get$('/next-config')

test/integration/production/test/index.test.js

@@ -15,7 +15,7 @@ import webdriver from 'next-webdriver'
 import fetch from 'node-fetch'
 import dynamicImportTests from '../../basic/test/dynamic'
 import security from './security'
-import {BUILD_MANIFEST, REACT_LOADABLE_MANIFEST, CLIENT_STATIC_FILES_RUNTIME_MAIN} from 'next/constants'
+import {BUILD_MANIFEST, REACT_LOADABLE_MANIFEST} from 'next/constants'
 
 const appDir = join(__dirname, '../')
 let appPort
@@ -68,8 +68,10 @@ describe('Production Usage', () => {
       // test dynamic chunk
       resources.push(url + reactLoadableManifest['../../components/hello1'][0].publicPath)
 
-      // test main.js
-      resources.push(url + buildManifest[CLIENT_STATIC_FILES_RUNTIME_MAIN][0])
+      // test main.js runtime etc
+      for (const item of buildManifest.pages['/']) {
+        resources.push(url + item)
+      }
 
       const responses = await Promise.all(resources.map((resource) => fetch(resource)))