Add CONFIG_FILE constant, add types for server/config.js (#4529)

This was pulled from #4518, it can already be merged so it's easier to get it in.

bin/next

@@ -2,6 +2,7 @@
 import { join } from 'path'
 import { spawn } from 'cross-spawn'
 import pkg from '../../package.json'
+import {CONFIG_FILE} from '../lib/constants'
 
 if (pkg.peerDependencies) {
   Object.keys(pkg.peerDependencies).forEach(dependency => {
@@ -89,9 +90,9 @@ let proc = startProcess()
 
 if (cmd === 'dev') {
   const {watchFile} = require('fs')
-  watchFile(`${process.cwd()}/next.config.js`, (cur, prev) => {
+  watchFile(`${process.cwd()}/${CONFIG_FILE}`, (cur, prev) => {
     if (cur.size > 0 || prev.size > 0) {
-      console.log('\n> Found a change in next.config.js, restarting the server...')
+      console.log(`\n> Found a change in ${CONFIG_FILE}, restarting the server...`)
       // Don't listen to 'close' now since otherwise parent gets killed by listener
       proc.removeAllListeners('close')
       proc.kill()

lib/constants.js

@@ -5,3 +5,4 @@ export const PHASE_DEVELOPMENT_SERVER = 'phase-development-server'
 export const PAGES_MANIFEST = 'pages-manifest.json'
 export const BUILD_MANIFEST = 'build-manifest.json'
 export const SERVER_DIRECTORY = 'server'
+export const CONFIG_FILE = 'next.config.js'

server/build/index.js

@@ -2,7 +2,7 @@ import { join } from 'path'
 import promisify from '../lib/promisify'
 import fs from 'fs'
 import webpack from 'webpack'
-import getConfig from '../config'
+import loadConfig from '../config'
 import { PHASE_PRODUCTION_BUILD } from '../../lib/constants'
 import getBaseWebpackConfig from './webpack'
 
@@ -10,7 +10,7 @@ const access = promisify(fs.access)
 const writeFile = promisify(fs.writeFile)
 
 export default async function build (dir, conf = null) {
-  const config = getConfig(PHASE_PRODUCTION_BUILD, dir, conf)
+  const config = loadConfig(PHASE_PRODUCTION_BUILD, dir, conf)
   const buildId = await config.generateBuildId() // defaults to a uuid
 
   try {

server/config.js

@@ -1,10 +1,26 @@
 // @flow
 import findUp from 'find-up'
 import uuid from 'uuid'
+import {CONFIG_FILE} from '../lib/constants'
 
-const cache = new Map()
+type WebpackConfig = *
 
-const defaultConfig = {
+type WebpackDevMiddlewareConfig = *
+
+export type NextConfig = {|
+  webpack: null | (webpackConfig: WebpackConfig, {dir: string, dev: boolean, isServer: boolean, buildId: string, config: NextConfig, defaultLoaders: {}, totalPages: number}) => WebpackConfig,
+  webpackDevMiddleware: null | (WebpackDevMiddlewareConfig: WebpackDevMiddlewareConfig) => WebpackDevMiddlewareConfig,
+  poweredByHeader: boolean,
+  distDir: string,
+  assetPrefix: string,
+  configOrigin: string,
+  useFileSystemPublicRoutes: boolean,
+  generateBuildId: () => string,
+  generateEtags: boolean,
+  pageExtensions: Array<string>
+|}
+
+const defaultConfig: NextConfig = {
   webpack: null,
   webpackDevMiddleware: null,
   poweredByHeader: true,
@@ -17,37 +33,28 @@ const defaultConfig = {
   pageExtensions: ['jsx', 'js']
 }
 
-export default function getConfig (phase: string, dir: string, customConfig?: ?Object) {
-  if (!cache.has(dir)) {
-    cache.set(dir, loadConfig(phase, dir, customConfig))
-  }
-  return cache.get(dir)
-}
+type PhaseFunction = (phase: string, options: {defaultConfig: NextConfig}) => NextConfig
 
-export function loadConfig (phase: string, dir: string, customConfig?: ?Object) {
-  if (customConfig && typeof customConfig === 'object') {
+export default function loadConfig (phase: string, dir: string, customConfig?: NextConfig): NextConfig {
+  if (customConfig) {
     customConfig.configOrigin = 'server'
-    return withDefaults(customConfig)
+    return {...defaultConfig, ...customConfig}
   }
-  const path: string = findUp.sync('next.config.js', {
+  const path: string = findUp.sync(CONFIG_FILE, {
     cwd: dir
   })
 
-  let userConfig = {}
-
+  // If config file was found
   if (path && path.length) {
     // $FlowFixMe
     const userConfigModule = require(path)
-    userConfig = userConfigModule.default || userConfigModule
-    if (typeof userConfigModule === 'function') {
-      userConfig = userConfigModule(phase, {defaultConfig})
+    const userConfigInitial: NextConfig | PhaseFunction = userConfigModule.default || userConfigModule
+    if (typeof userConfigInitial === 'function') {
+      return {...defaultConfig, configOrigin: CONFIG_FILE, ...userConfigInitial(phase, {defaultConfig})}
     }
-    userConfig.configOrigin = 'next.config.js'
+
+    return {...defaultConfig, configOrigin: CONFIG_FILE, ...userConfigInitial}
   }
 
-  return withDefaults(userConfig)
-}
-
-function withDefaults (config: Object) {
-  return Object.assign({}, defaultConfig, config)
+  return defaultConfig
 }

server/export.js

@@ -4,8 +4,8 @@ import mkdirp from 'mkdirp-then'
 import walk from 'walk'
 import { extname, resolve, join, dirname, sep } from 'path'
 import { existsSync, readFileSync, writeFileSync } from 'fs'
-import getConfig from './config'
-import {PHASE_EXPORT, SERVER_DIRECTORY, PAGES_MANIFEST} from '../lib/constants'
+import loadConfig from './config'
+import {PHASE_EXPORT, SERVER_DIRECTORY, PAGES_MANIFEST, CONFIG_FILE} from '../lib/constants'
 import { renderToHTML } from './render'
 import { getAvailableChunks } from './utils'
 import { setAssetPrefix } from '../lib/asset'
@@ -13,7 +13,7 @@ import * as envConfig from '../lib/runtime-config'
 
 export default async function (dir, options, configuration) {
   dir = resolve(dir)
-  const nextConfig = configuration || getConfig(PHASE_EXPORT, dir)
+  const nextConfig = configuration || loadConfig(PHASE_EXPORT, dir)
   const nextDir = join(dir, nextConfig.distDir)
 
   log(`> using build directory: ${nextDir}`)
@@ -73,9 +73,9 @@ export default async function (dir, options, configuration) {
 
   await copyPages(nextDir, outDir, buildId)
 
-  // Get the exportPathMap from the `next.config.js`
+  // Get the exportPathMap from the config file
   if (typeof nextConfig.exportPathMap !== 'function') {
-    console.log('> No "exportPathMap" found in "next.config.js". Generating map from "./pages"')
+    console.log(`> No "exportPathMap" found in "${CONFIG_FILE}". Generating map from "./pages"`)
     nextConfig.exportPathMap = async (defaultMap) => {
       return defaultMap
     }

server/index.js

@@ -14,15 +14,16 @@ import {
 } from './render'
 import Router from './router'
 import { getAvailableChunks, isInternalUrl } from './utils'
-import getConfig from './config'
+import loadConfig from './config'
 import {PHASE_PRODUCTION_SERVER, PHASE_DEVELOPMENT_SERVER} from '../lib/constants'
-// We need to go up one more level since we are in the `dist` directory
-import pkg from '../../package'
 import * as asset from '../lib/asset'
 import * as envConfig from '../lib/runtime-config'
 import { isResSent } from '../lib/utils'
 import isAsyncSupported from './lib/is-async-supported'
 
+// We need to go up one more level since we are in the `dist` directory
+import pkg from '../../package'
+
 const access = promisify(fs.access)
 
 const blockedPages = {
@@ -39,7 +40,7 @@ export default class Server {
     this.router = new Router()
     this.http = null
     const phase = dev ? PHASE_DEVELOPMENT_SERVER : PHASE_PRODUCTION_SERVER
-    this.nextConfig = getConfig(phase, this.dir, conf)
+    this.nextConfig = loadConfig(phase, this.dir, conf)
     this.dist = this.nextConfig.distDir
 
     this.hotReloader = dev ? this.getHotReloader(this.dir, { quiet, config: this.nextConfig }) : null

test/isolated/config.test.js

@@ -1,7 +1,7 @@
 /* global describe, it, expect */
 
 import {join} from 'path'
-import getConfig, {loadConfig} from '../../dist/server/config'
+import loadConfig from '../../dist/server/config'
 import {PHASE_DEVELOPMENT_SERVER} from '../../dist/lib/constants'
 
 const pathToConfig = join(__dirname, '_resolvedata', 'without-function')
@@ -32,10 +32,4 @@ describe('config', () => {
     const config = loadConfig(PHASE_DEVELOPMENT_SERVER, null, null)
     expect(config.webpack).toBe(null)
   })
-
-  it('Should cache on getConfig', () => {
-    const config = getConfig(PHASE_DEVELOPMENT_SERVER, pathToConfig)
-    const config2 = getConfig(PHASE_DEVELOPMENT_SERVER, pathToConfig, {extraConfig: true}) // won't add extraConfig because it's cached.
-    expect(config === config2).toBe(true)
-  })
 })