Remove buildId from dynamic import URLs (#3498)

* Use without .js for the filename.

* Modify the chunk filename to add .js via webpack

* Add import chunk's hash to the filename via webpack.

* Remove buildId from dynamic import urls.

* Make sure next-export work with dynamic imports

server/build/babel/plugins/handle-import.js

@@ -21,9 +21,9 @@ const buildImport = (args) => (template(`
         eval('require.ensure = function (deps, callback) { callback(require) }')
         require.ensure([], (require) => {
           let m = require(SOURCE)
-          m.__webpackChunkName = '${args.name}.js'
+          m.__webpackChunkName = '${args.name}'
           resolve(m);
-        }, 'chunks/${args.name}.js');
+        }, 'chunks/${args.name}');
       })
       :
       new (require('next/dynamic').SameLoopPromise)((resolve, reject) => {
@@ -40,7 +40,7 @@ const buildImport = (args) => (template(`
           } catch(error) {
             reject(error)
           }
-        }, 'chunks/${args.name}.js');
+        }, 'chunks/${args.name}');
       })
   )
 `))

server/build/plugins/dynamic-chunks-plugin.js

@@ -1,6 +1,6 @@
 import { ConcatSource } from 'webpack-sources'
 
-const isImportChunk = /^chunks[/\\].*\.js$/
+const isImportChunk = /^chunks[/\\]/
 const matchChunkName = /^chunks[/\\](.*)$/
 
 class DynamicChunkTemplatePlugin {

server/build/webpack.js

@@ -325,7 +325,7 @@ export default async function createCompiler (dir, { buildId, dev = false, quiet
       path: buildDir ? join(buildDir, '.next') : join(dir, config.distDir),
       filename: '[name]',
       libraryTarget: 'commonjs2',
-      publicPath: `/_next/${buildId}/webpack/`,
+      publicPath: `/_next/webpack/`,
       strictModuleExceptionHandling: true,
       devtoolModuleFilenameTemplate ({ resourcePath }) {
         const hash = createHash('sha1')
@@ -336,7 +336,7 @@ export default async function createCompiler (dir, { buildId, dev = false, quiet
         return `webpack:///${resourcePath}?${id}`
       },
       // This saves chunks with the name given via require.ensure()
-      chunkFilename: '[name]'
+      chunkFilename: '[name]-[chunkhash].js'
     },
     resolve: {
       extensions: ['.js', '.jsx', '.json'],

server/document.js

@@ -71,12 +71,12 @@ export class Head extends Component {
 
   getPreloadDynamicChunks () {
     const { chunks, __NEXT_DATA__ } = this.context._documentProps
-    let { assetPrefix, buildId } = __NEXT_DATA__
+    let { assetPrefix } = __NEXT_DATA__
-    return chunks.map((chunk) => (
+    return chunks.filenames.map((chunk) => (
       <link
         key={chunk}
         rel='preload'
-        href={`${assetPrefix}/_next/${buildId}/webpack/chunks/${chunk}`}
+        href={`${assetPrefix}/_next/webpack/chunks/${chunk}`}
         as='script'
       />
     ))
@@ -157,15 +157,15 @@ export class NextScript extends Component {
 
   getDynamicChunks () {
     const { chunks, __NEXT_DATA__ } = this.context._documentProps
-    let { assetPrefix, buildId } = __NEXT_DATA__
+    let { assetPrefix } = __NEXT_DATA__
     return (
       <Fragment>
-        {chunks.map((chunk) => (
+        {chunks.filenames.map((chunk) => (
           <script
             async
             key={chunk}
             type='text/javascript'
-            src={`${assetPrefix}/_next/${buildId}/webpack/chunks/${chunk}`}
+            src={`${assetPrefix}/_next/webpack/chunks/${chunk}`}
           />
         ))}
       </Fragment>
@@ -177,7 +177,7 @@ export class NextScript extends Component {
     const { pathname, buildId, assetPrefix } = __NEXT_DATA__
     const pagePathname = getPagePathname(pathname)
 
-    __NEXT_DATA__.chunks = chunks
+    __NEXT_DATA__.chunks = chunks.names
 
     return <Fragment>
       {staticMarkup ? null : <script nonce={this.props.nonce} dangerouslySetInnerHTML={{

server/export.js

@@ -51,10 +51,10 @@ export default async function (dir, options, configuration) {
   if (existsSync(join(nextDir, 'chunks'))) {
     log('  copying dynamic import chunks')
 
-    await mkdirp(join(outDir, '_next', buildId, 'webpack'))
+    await mkdirp(join(outDir, '_next', 'webpack'))
     await cp(
       join(nextDir, 'chunks'),
-      join(outDir, '_next', buildId, 'webpack', 'chunks')
+      join(outDir, '_next', 'webpack', 'chunks')
     )
   }
 

server/hot-reloader.js

@@ -179,7 +179,7 @@ export default class HotReloader {
     ]
 
     let webpackDevMiddlewareConfig = {
-      publicPath: `/_next/${this.buildId}/webpack/`,
+      publicPath: `/_next/webpack/`,
       noInfo: true,
       quiet: true,
       clientLogLevel: 'warning',

server/index.js

@@ -136,21 +136,17 @@ export default class Server {
       },
 
       // This is to support, webpack dynamic imports in production.
-      '/_next/:buildId/webpack/chunks/:name': async (req, res, params) => {
+      '/_next/webpack/chunks/:name': async (req, res, params) => {
-        if (!this.handleBuildId(params.buildId, res)) {
+        // Cache aggressively in production
-          return this.send404(res)
+        if (!this.dev) {
+          res.setHeader('Cache-Control', 'max-age=31536000, immutable')
         }
-
         const p = join(this.dir, this.dist, 'chunks', params.name)
         await this.serveStatic(req, res, p)
       },
 
       // This is to support, webpack dynamic import support with HMR
-      '/_next/:buildId/webpack/:id': async (req, res, params) => {
+      '/_next/webpack/:id': async (req, res, params) => {
-        if (!this.handleBuildId(params.buildId, res)) {
-          return this.send404(res)
-        }
-
         const p = join(this.dir, this.dist, 'chunks', params.id)
         await this.serveStatic(req, res, p)
       },

server/render.js

@@ -1,5 +1,4 @@
 import { join } from 'path'
-import { existsSync } from 'fs'
 import { createElement } from 'react'
 import { renderToString, renderToStaticMarkup } from 'react-dom/server'
 import send from 'send'
@@ -10,6 +9,7 @@ import getConfig from './config'
 import resolvePath from './resolve'
 import { Router } from '../lib/router'
 import { loadGetInitialProps } from '../lib/utils'
+import { getAvailableChunks } from './utils'
 import Head, { defaultHead } from '../lib/head'
 import App from '../lib/app'
 import ErrorDebug from '../lib/error-debug'
@@ -246,15 +246,22 @@ async function ensurePage (page, { dir, hotReloader }) {
 
 function loadChunks ({ dev, dir, dist, availableChunks }) {
   const flushedChunks = flushChunks()
-  const validChunks = []
+  const response = {
+    names: [],
+    filenames: []
+  }
+
+  if (dev) {
+    availableChunks = getAvailableChunks(dir, dist)
+  }
 
   for (var chunk of flushedChunks) {
-    const filename = join(dir, dist, 'chunks', chunk)
+    const filename = availableChunks[chunk]
-    const exists = dev ? existsSync(filename) : availableChunks[chunk]
+    if (filename) {
-    if (exists) {
+      response.names.push(chunk)
-      validChunks.push(chunk)
+      response.filenames.push(filename)
     }
   }
 
-  return validChunks
+  return response
 }

server/utils.js

@@ -13,7 +13,8 @@ export function getAvailableChunks (dir, dist) {
 
   chunkFiles.forEach(filename => {
     if (/\.js$/.test(filename)) {
-      chunksMap[filename] = true
+      const chunkName = filename.replace(/-.*/, '')
+      chunksMap[chunkName] = filename
     }
   })