Add node_modules bundling under the --lambdas flag for next build (#5690)

* Add node_modules bundling under the —lambdas flag for next build

* Run minifier when lambdas mode is enabled

* Add lambdas option to next.config.js

* Add test for lambdas option

packages/next/bin/next-build

@@ -7,9 +7,10 @@ import { printAndExit } from '../server/lib/utils'
 
 const argv = parseArgs(process.argv.slice(2), {
   alias: {
-    h: 'help'
+    h: 'help',
+    l: 'lambdas'
   },
-  boolean: ['h']
+  boolean: ['h', 'l']
 })
 
 if (argv.help) {
@@ -28,6 +29,7 @@ if (argv.help) {
 }
 
 const dir = resolve(argv._[0] || '.')
+const lambdas = argv.lambdas
 
 // Check if pages dir exists and warn if not
 if (!existsSync(dir)) {
@@ -42,7 +44,7 @@ if (!existsSync(join(dir, 'pages'))) {
   printAndExit('> Couldn\'t find a `pages` directory. Please create one under the project root')
 }
 
-build(dir)
+build(dir, null, lambdas)
   .catch((err) => {
     printAndExit(err)
   })

packages/next/build/index.js

@@ -32,8 +32,9 @@ async function ensureProjectDirectoryIsWriteAble (dir) {
   }
 }
 
-export default async function build (dir, conf = null) {
+export default async function build (dir, conf = null, lambdas = false) {
   const config = loadConfig(PHASE_PRODUCTION_BUILD, dir, conf)
+  const lambdasOption = config.lambdas ? config.lambdas : lambdas
   const distDir = join(dir, config.distDir)
   const buildId = await generateBuildId(config.generateBuildId, nanoid)
 
@@ -41,8 +42,8 @@ export default async function build (dir, conf = null) {
 
   try {
     const configs = await Promise.all([
-      getBaseWebpackConfig(dir, { buildId, isServer: false, config }),
+      getBaseWebpackConfig(dir, { buildId, isServer: false, config, lambdas: lambdasOption }),
-      getBaseWebpackConfig(dir, { buildId, isServer: true, config })
+      getBaseWebpackConfig(dir, { buildId, isServer: true, config, lambdas: lambdasOption })
     ])
 
     await runCompiler(configs)

packages/next/build/webpack.js

@@ -25,13 +25,41 @@ import AssetsSizePlugin from './webpack/plugins/assets-size-plugin'
 // The externals config makes sure that
 // on the server side when modules are
 // in node_modules they don't get compiled by webpack
-function externalsConfig (dir, isServer) {
+function externalsConfig (dir, isServer, lambdas) {
   const externals = []
 
   if (!isServer) {
     return externals
   }
 
+  // When lambdas mode is enabled all node_modules will be compiled into the server bundles
+  // So that all dependencies can be devDependencies and are not required to be installed
+  if (lambdas) {
+    return [
+      (context, request, callback) => {
+        resolve(request, { basedir: context, preserveSymlinks: true }, (err, res) => {
+          if (err) {
+            return callback()
+          }
+          if (res.match(/next-server[/\\]dist[/\\]lib[/\\]head/)) {
+            return callback(null, `commonjs next-server/dist/lib/head.js`)
+          }
+          if (res.match(/next-server[/\\]dist[/\\]lib[/\\]asset/)) {
+            return callback(null, `commonjs next-server/dist/lib/asset.js`)
+          }
+          if (res.match(/next-server[/\\]dist[/\\]lib[/\\]runtime-config/)) {
+            return callback(null, `commonjs next-server/dist/lib/runtime-config.js`)
+          }
+          // Default pages have to be transpiled
+          if (res.match(/next-server[/\\]dist[/\\]lib[/\\]loadable/)) {
+            return callback(null, `commonjs next-server/dist/lib/loadable.js`)
+          }
+          callback()
+        })
+      }
+    ]
+  }
+
   const notExternalModules = ['next/app', 'next/document', 'next/error', 'http-status', 'string-hash']
 
   externals.push((context, request, callback) => {
@@ -74,7 +102,26 @@ function externalsConfig (dir, isServer) {
   return externals
 }
 
-function optimizationConfig ({dir, dev, isServer, totalPages}) {
+function optimizationConfig ({dir, dev, isServer, totalPages, lambdas}) {
+  if (isServer && lambdas) {
+    return {
+      splitChunks: false,
+      minimizer: [
+        new TerserPlugin({
+          parallel: true,
+          sourceMap: false,
+          cache: true,
+          cacheKeys: (keys) => {
+            // path changes per build because we add buildId
+            // because the input is already hashed the path is not needed
+            delete keys.path
+            return keys
+          }
+        })
+      ]
+    }
+  }
+
   if (isServer) {
     return {
       splitChunks: false,
@@ -135,10 +182,11 @@ type BaseConfigContext = {|
   dev: boolean,
   isServer: boolean,
   buildId: string,
-  config: NextConfig
+  config: NextConfig,
+  lambdas: boolean
 |}
 
-export default async function getBaseWebpackConfig (dir: string, {dev = false, isServer = false, buildId, config}: BaseConfigContext) {
+export default async function getBaseWebpackConfig (dir: string, {dev = false, isServer = false, buildId, config, lambdas = false}: BaseConfigContext) {
   const defaultLoaders = {
     babel: {
       loader: 'next-babel-loader',
@@ -194,8 +242,8 @@ export default async function getBaseWebpackConfig (dir: string, {dev = false, i
     name: isServer ? 'server' : 'client',
     cache: true,
     target: isServer ? 'node' : 'web',
-    externals: externalsConfig(dir, isServer),
+    externals: externalsConfig(dir, isServer, lambdas),
-    optimization: optimizationConfig({dir, dev, isServer, totalPages}),
+    optimization: optimizationConfig({dir, dev, isServer, totalPages, lambdas}),
     recordsPath: path.join(outputPath, 'records.json'),
     context: dir,
     // Kept as function to be backwards compatible

test/integration/lambdas/next.config.js

@@ -0,0 +1,7 @@
+module.exports = {
+  onDemandEntries: {
+    // Make sure entries are not getting disposed.
+    maxInactiveAge: 1000 * 60 * 60
+  },
+  lambdas: true
+}

test/integration/lambdas/pages/index.js

@@ -0,0 +1 @@
+export default () => 'Hello World'

test/integration/lambdas/test/index.test.js

@@ -0,0 +1,38 @@
+/* eslint-env jest */
+/* global jasmine, test */
+import { join } from 'path'
+import {
+  nextServer,
+  nextBuild,
+  startApp,
+  stopApp,
+  renderViaHTTP
+} from 'next-test-utils'
+
+const appDir = join(__dirname, '../')
+let appPort
+let server
+let app
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60 * 5
+
+const context = {}
+
+describe('Lambdas', () => {
+  beforeAll(async () => {
+    await nextBuild(appDir)
+    app = nextServer({
+      dir: join(__dirname, '../'),
+      dev: false,
+      quiet: true
+    })
+
+    server = await startApp(app)
+    context.appPort = appPort = server.address().port
+  })
+  afterAll(() => stopApp(server))
+
+  it('should render the page', async () => {
+    const html = await renderViaHTTP(appPort, '/')
+    expect(html).toMatch(/Hello World/)
+  })
+})