misc: remove IIFE from webpack build fn (5/6) (#45459)

This is mostly useless now that the compilation is self contained to a file.  ## Bug - [ ] Related issues linked using `fixes #number` - [ ] Integration tests added - [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md) ## Feature - [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR. - [ ] Related issues linked using `fixes #number` - [ ] [e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs) tests added - [ ] Documentation added - [ ] Telemetry added. In case of a feature if it's used or not. - [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md) ## Documentation / Examples - [ ] Make sure the linting passes by running `pnpm build && pnpm lint` - [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)
vercel · Feb 1, 2023 · b967bdf · b967bdf
1 parent e3a69f0
commit b967bdf
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Showing 3 changed files with 212 additions and 139 deletions.
diff --git a/packages/next/src/build/webpack-build.ts b/packages/next/src/build/webpack-build.ts
@@ -6,6 +6,7 @@ import {
   COMPILER_NAMES,
   CLIENT_STATIC_FILES_RUNTIME_MAIN_APP,
   APP_CLIENT_INTERNALS,
+  PHASE_PRODUCTION_BUILD,
 } from '../shared/lib/constants'
 import { runCompiler } from './compiler'
 import * as Log from './output/log'
@@ -14,8 +15,10 @@ import { NextError } from '../lib/is-error'
 import { injectedClientEntries } from './webpack/plugins/flight-client-entry-plugin'
 import { TelemetryPlugin } from './webpack/plugins/telemetry-plugin'
 import { NextBuildContext } from './build-context'
-
+import { isMainThread, parentPort, Worker, workerData } from 'worker_threads'
 import { createEntrypoints } from './entries'
+import loadConfig from '../server/config'
+import { trace } from '../trace'
 
 type CompilerResult = {
   errors: webpack.StatsError[]
@@ -33,7 +36,7 @@ function isTelemetryPlugin(plugin: unknown): plugin is TelemetryPlugin {
   return plugin instanceof TelemetryPlugin
 }
 
-export async function webpackBuild(): Promise<number> {
+async function webpackBuildImpl(): Promise<number> {
   let result: CompilerResult | null = {
     warnings: [],
     errors: [],
@@ -44,155 +47,151 @@ export async function webpackBuild(): Promise<number> {
   const buildSpinner = NextBuildContext.buildSpinner
   const dir = NextBuildContext.dir!
 
-  await (async () => {
-    // IIFE to isolate locals and avoid retaining memory too long
-    const runWebpackSpan = nextBuildSpan.traceChild('run-webpack-compiler')
-
-    const entrypoints = await nextBuildSpan
-      .traceChild('create-entrypoints')
-      .traceAsyncFn(() =>
-        createEntrypoints({
-          buildId: NextBuildContext.buildId!,
-          config: NextBuildContext.config!,
-          envFiles: NextBuildContext.loadedEnvFiles!,
-          isDev: false,
-          rootDir: dir,
-          pageExtensions: NextBuildContext.config!.pageExtensions!,
-          pagesDir: NextBuildContext.pagesDir!,
-          appDir: NextBuildContext.appDir!,
-          pages: NextBuildContext.mappedPages!,
-          appPaths: NextBuildContext.mappedAppPages!,
-          previewMode: NextBuildContext.previewProps!,
-          rootPaths: NextBuildContext.mappedRootPaths!,
-        })
-      )
+  const runWebpackSpan = nextBuildSpan.traceChild('run-webpack-compiler')
+  const entrypoints = await nextBuildSpan
+    .traceChild('create-entrypoints')
+    .traceAsyncFn(() =>
+      createEntrypoints({
+        buildId: NextBuildContext.buildId!,
+        config: NextBuildContext.config!,
+        envFiles: NextBuildContext.loadedEnvFiles!,
+        isDev: false,
+        rootDir: dir,
+        pageExtensions: NextBuildContext.config!.pageExtensions!,
+        pagesDir: NextBuildContext.pagesDir!,
+        appDir: NextBuildContext.appDir!,
+        pages: NextBuildContext.mappedPages!,
+        appPaths: NextBuildContext.mappedAppPages!,
+        previewMode: NextBuildContext.previewProps!,
+        rootPaths: NextBuildContext.mappedRootPaths!,
+      })
+    )
 
-    const commonWebpackOptions = {
-      isServer: false,
-      buildId: NextBuildContext.buildId!,
-      config: NextBuildContext.config!,
-      target: NextBuildContext.config!.target!,
-      appDir: NextBuildContext.appDir!,
-      pagesDir: NextBuildContext.pagesDir!,
-      rewrites: NextBuildContext.rewrites!,
-      reactProductionProfiling: NextBuildContext.reactProductionProfiling!,
-      noMangling: NextBuildContext.noMangling!,
-    }
+  const commonWebpackOptions = {
+    isServer: false,
+    buildId: NextBuildContext.buildId!,
+    config: NextBuildContext.config!,
+    target: NextBuildContext.config!.target!,
+    appDir: NextBuildContext.appDir!,
+    pagesDir: NextBuildContext.pagesDir!,
+    rewrites: NextBuildContext.rewrites!,
+    reactProductionProfiling: NextBuildContext.reactProductionProfiling!,
+    noMangling: NextBuildContext.noMangling!,
+  }
 
-    const configs = await runWebpackSpan
-      .traceChild('generate-webpack-config')
-      .traceAsyncFn(() =>
-        Promise.all([
-          getBaseWebpackConfig(dir, {
-            ...commonWebpackOptions,
-            middlewareMatchers: entrypoints.middlewareMatchers,
-            runWebpackSpan,
-            compilerType: COMPILER_NAMES.client,
-            entrypoints: entrypoints.client,
-          }),
-          getBaseWebpackConfig(dir, {
-            ...commonWebpackOptions,
-            runWebpackSpan,
-            middlewareMatchers: entrypoints.middlewareMatchers,
-            compilerType: COMPILER_NAMES.server,
-            entrypoints: entrypoints.server,
-          }),
-          getBaseWebpackConfig(dir, {
-            ...commonWebpackOptions,
-            runWebpackSpan,
-            middlewareMatchers: entrypoints.middlewareMatchers,
-            compilerType: COMPILER_NAMES.edgeServer,
-            entrypoints: entrypoints.edgeServer,
-          }),
-        ])
-      )
+  const configs = await runWebpackSpan
+    .traceChild('generate-webpack-config')
+    .traceAsyncFn(() =>
+      Promise.all([
+        getBaseWebpackConfig(dir, {
+          ...commonWebpackOptions,
+          middlewareMatchers: entrypoints.middlewareMatchers,
+          runWebpackSpan,
+          compilerType: COMPILER_NAMES.client,
+          entrypoints: entrypoints.client,
+        }),
+        getBaseWebpackConfig(dir, {
+          ...commonWebpackOptions,
+          runWebpackSpan,
+          middlewareMatchers: entrypoints.middlewareMatchers,
+          compilerType: COMPILER_NAMES.server,
+          entrypoints: entrypoints.server,
+        }),
+        getBaseWebpackConfig(dir, {
+          ...commonWebpackOptions,
+          runWebpackSpan,
+          middlewareMatchers: entrypoints.middlewareMatchers,
+          compilerType: COMPILER_NAMES.edgeServer,
+          entrypoints: entrypoints.edgeServer,
+        }),
+      ])
+    )
 
-    const clientConfig = configs[0]
+  const clientConfig = configs[0]
 
-    if (
-      clientConfig.optimization &&
-      (clientConfig.optimization.minimize !== true ||
-        (clientConfig.optimization.minimizer &&
-          clientConfig.optimization.minimizer.length === 0))
-    ) {
-      Log.warn(
-        `Production code optimization has been disabled in your project. Read more: https://nextjs.org/docs/messages/minification-disabled`
-      )
-    }
+  if (
+    clientConfig.optimization &&
+    (clientConfig.optimization.minimize !== true ||
+      (clientConfig.optimization.minimizer &&
+        clientConfig.optimization.minimizer.length === 0))
+  ) {
+    Log.warn(
+      `Production code optimization has been disabled in your project. Read more: https://nextjs.org/docs/messages/minification-disabled`
+    )
+  }
 
-    webpackBuildStart = process.hrtime()
+  webpackBuildStart = process.hrtime()
 
-    // We run client and server compilation separately to optimize for memory usage
-    await runWebpackSpan.traceAsyncFn(async () => {
-      // Run the server compilers first and then the client
-      // compiler to track the boundary of server/client components.
-      let clientResult: SingleCompilerResult | null = null
+  // We run client and server compilation separately to optimize for memory usage
+  await runWebpackSpan.traceAsyncFn(async () => {
+    // Run the server compilers first and then the client
+    // compiler to track the boundary of server/client components.
+    let clientResult: SingleCompilerResult | null = null
 
-      // During the server compilations, entries of client components will be
-      // injected to this set and then will be consumed by the client compiler.
-      injectedClientEntries.clear()
+    // During the server compilations, entries of client components will be
+    // injected to this set and then will be consumed by the client compiler.
+    injectedClientEntries.clear()
 
-      const serverResult = await runCompiler(configs[1], {
-        runWebpackSpan,
-      })
-      const edgeServerResult = configs[2]
-        ? await runCompiler(configs[2], { runWebpackSpan })
-        : null
-
-      // Only continue if there were no errors
-      if (!serverResult.errors.length && !edgeServerResult?.errors.length) {
-        injectedClientEntries.forEach((value, key) => {
-          const clientEntry = clientConfig.entry as webpack.EntryObject
-          if (key === APP_CLIENT_INTERNALS) {
-            clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP] = [
-              // TODO-APP: cast clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP] to type EntryDescription once it's available from webpack
-              // @ts-expect-error clientEntry['main-app'] is type EntryDescription { import: ... }
-              ...clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP].import,
-              value,
-            ]
-          } else {
-            clientEntry[key] = {
-              dependOn: [CLIENT_STATIC_FILES_RUNTIME_MAIN_APP],
-              import: value,
-            }
+    const serverResult = await runCompiler(configs[1], {
+      runWebpackSpan,
+    })
+    const edgeServerResult = configs[2]
+      ? await runCompiler(configs[2], { runWebpackSpan })
+      : null
+
+    // Only continue if there were no errors
+    if (!serverResult.errors.length && !edgeServerResult?.errors.length) {
+      injectedClientEntries.forEach((value, key) => {
+        const clientEntry = clientConfig.entry as webpack.EntryObject
+        if (key === APP_CLIENT_INTERNALS) {
+          clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP] = [
+            // TODO-APP: cast clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP] to type EntryDescription once it's available from webpack
+            // @ts-expect-error clientEntry['main-app'] is type EntryDescription { import: ... }
+            ...clientEntry[CLIENT_STATIC_FILES_RUNTIME_MAIN_APP].import,
+            value,
+          ]
+        } else {
+          clientEntry[key] = {
+            dependOn: [CLIENT_STATIC_FILES_RUNTIME_MAIN_APP],
+            import: value,
           }
-        })
+        }
+      })
 
-        clientResult = await runCompiler(clientConfig, {
-          runWebpackSpan,
-        })
-      }
+      clientResult = await runCompiler(clientConfig, {
+        runWebpackSpan,
+      })
+    }
 
-      result = {
-        warnings: ([] as any[])
-          .concat(
-            clientResult?.warnings,
-            serverResult?.warnings,
-            edgeServerResult?.warnings
-          )
-          .filter(nonNullable),
-        errors: ([] as any[])
-          .concat(
-            clientResult?.errors,
-            serverResult?.errors,
-            edgeServerResult?.errors
-          )
-          .filter(nonNullable),
-        stats: [
-          clientResult?.stats,
-          serverResult?.stats,
-          edgeServerResult?.stats,
-        ],
-      }
-    })
-    result = nextBuildSpan
-      .traceChild('format-webpack-messages')
-      .traceFn(() => formatWebpackMessages(result, true))
+    result = {
+      warnings: ([] as any[])
+        .concat(
+          clientResult?.warnings,
+          serverResult?.warnings,
+          edgeServerResult?.warnings
+        )
+        .filter(nonNullable),
+      errors: ([] as any[])
+        .concat(
+          clientResult?.errors,
+          serverResult?.errors,
+          edgeServerResult?.errors
+        )
+        .filter(nonNullable),
+      stats: [
+        clientResult?.stats,
+        serverResult?.stats,
+        edgeServerResult?.stats,
+      ],
+    }
+  })
+  result = nextBuildSpan
+    .traceChild('format-webpack-messages')
+    .traceFn(() => formatWebpackMessages(result, true)) as CompilerResult
 
-    NextBuildContext.telemetryPlugin = (
-      clientConfig as webpack.Configuration
-    ).plugins?.find(isTelemetryPlugin)
-  })()
+  NextBuildContext.telemetryPlugin = (
+    clientConfig as webpack.Configuration
+  ).plugins?.find(isTelemetryPlugin)
 
   const webpackBuildEnd = process.hrtime(webpackBuildStart)
   if (buildSpinner) {
@@ -248,3 +247,70 @@ export async function webpackBuild(): Promise<number> {
     return webpackBuildEnd[0]
   }
 }
+
+// the main function when this file is run as a worker
+async function workerMain() {
+  const { buildContext } = workerData
+  // setup new build context from the serialized data passed from the parent
+  Object.assign(NextBuildContext, buildContext)
+
+  /// load the config because it's not serializable
+  NextBuildContext.config = await loadConfig(
+    PHASE_PRODUCTION_BUILD,
+    NextBuildContext.dir!,
+    undefined,
+    undefined,
+    true
+  )
+  NextBuildContext.nextBuildSpan = trace('next-build')
+
+  try {
+    const result = await webpackBuildImpl()
+    parentPort!.postMessage(result)
+  } catch (e) {
+    parentPort!.postMessage(e)
+  } finally {
+    process.exit(0)
+  }
+}
+
+if (!isMainThread) {
+  workerMain()
+}
+
+async function webpackBuildWithWorker() {
+  const {
+    config,
+    telemetryPlugin,
+    buildSpinner,
+    nextBuildSpan,
+    ...prunedBuildContext
+  } = NextBuildContext
+  const worker = new Worker(new URL(import.meta.url), {
+    workerData: {
+      buildContext: prunedBuildContext,
+    },
+  })
+
+  const result = await new Promise((resolve, reject) => {
+    worker.on('message', resolve)
+    worker.on('error', reject)
+    worker.on('exit', (code) => {
+      if (code !== 0) {
+        reject(new Error(`Worker stopped with exit code ${code}`))
+      }
+    })
+  })
+
+  return result as number
+}
+
+export async function webpackBuild() {
+  const config = NextBuildContext.config!
+
+  if (config.experimental.webpackBuildWorker) {
+    return await webpackBuildWithWorker()
+  } else {
+    return await webpackBuildImpl()
+  }
+}
diff --git a/packages/next/src/server/config-schema.ts b/packages/next/src/server/config-schema.ts
@@ -438,6 +438,9 @@ const configSchema = {
         mdxRs: {
           type: 'boolean',
         },
+        webpackBuildWorker: {
+          type: 'boolean',
+        },
         turbopackLoaders: {
           type: 'object',
         },