refactor(core): refactor SSG infrastructure

packages/docusaurus-bundler/src/index.ts

@@ -15,6 +15,10 @@ export {
 } from './currentBundler';
 
 export {getMinimizers} from './minification';
-export {getHtmlMinifier, type HtmlMinifier} from './minifyHtml';
+export {
+  getHtmlMinifier,
+  type HtmlMinifier,
+  type HtmlMinifierType,
+} from './minifyHtml';
 export {createJsLoaderFactory} from './loaders/jsLoader';
 export {createStyleLoadersFactory} from './loaders/styleLoader';

packages/docusaurus-bundler/src/minifyHtml.ts

@@ -7,11 +7,12 @@
 
 import {minify as terserHtmlMinifier} from 'html-minifier-terser';
 import {importSwcHtmlMinifier} from './importFaster';
-import type {DocusaurusConfig} from '@docusaurus/types';
 
 // Historical env variable
 const SkipHtmlMinification = process.env.SKIP_HTML_MINIFICATION === 'true';
 
+export type HtmlMinifierType = 'swc' | 'terser';
+
 export type HtmlMinifierResult = {
   code: string;
   warnings: string[];
@@ -25,24 +26,15 @@ const NoopMinifier: HtmlMinifier = {
   minify: async (html: string) => ({code: html, warnings: []}),
 };
 
-type SiteConfigSlice = {
-  future: {
-    experimental_faster: Pick<
-      DocusaurusConfig['future']['experimental_faster'],
-      'swcHtmlMinimizer'
-    >;
-  };
-};
-
 export async function getHtmlMinifier({
-  siteConfig,
+  type,
 }: {
-  siteConfig: SiteConfigSlice;
+  type: HtmlMinifierType;
 }): Promise<HtmlMinifier> {
   if (SkipHtmlMinification) {
     return NoopMinifier;
   }
-  if (siteConfig.future.experimental_faster.swcHtmlMinimizer) {
+  if (type === 'swc') {
     return getSwcMinifier();
   } else {
     return getTerserMinifier();

packages/docusaurus-logger/src/perfLogger.ts

@@ -9,15 +9,16 @@ import logger from './logger';
 
 // For now this is a private env variable we use internally
 // But we'll want to expose this feature officially some day
-const PerfDebuggingEnabled: boolean = !!process.env.DOCUSAURUS_PERF_LOGGER;
+const PerfDebuggingEnabled: boolean =
+  process.env.DOCUSAURUS_PERF_LOGGER === 'true';
 
 const Thresholds = {
   min: 5,
   yellow: 100,
   red: 1000,
 };
 
-const PerfPrefix = logger.yellow(`[PERF] `);
+const PerfPrefix = logger.yellow(`[PERF]`);
 
 // This is what enables to "see the parent stack" for each log
 // Parent1 > Parent2 > Parent3 > child trace
@@ -42,6 +43,14 @@ type Memory = {
   after: NodeJS.MemoryUsage;
 };
 
+function getMemory(): NodeJS.MemoryUsage {
+  // Before reading memory stats, we explicitly call the GC
+  // Note: this only works when Node.js option "--expose-gc" is provided
+  globalThis.gc?.();
+
+  return process.memoryUsage();
+}
+
 function createPerfLogger(): PerfLoggerAPI {
   if (!PerfDebuggingEnabled) {
     const noop = () => {};
@@ -73,29 +82,35 @@ function createPerfLogger(): PerfLoggerAPI {
     );
   };
 
+  const formatStatus = (error: Error | undefined): string => {
+    return error ? logger.red('[KO]') : ''; // logger.green('[OK]');
+  };
+
   const printPerfLog = ({
     label,
     duration,
     memory,
+    error,
   }: {
     label: string;
     duration: number;
     memory: Memory;
+    error: Error | undefined;
   }) => {
     if (duration < Thresholds.min) {
       return;
     }
     console.log(
-      `${PerfPrefix + label} - ${formatDuration(duration)} - ${formatMemory(
-        memory,
-      )}`,
+      `${PerfPrefix}${formatStatus(error)} ${label} - ${formatDuration(
+        duration,
+      )} - ${formatMemory(memory)}`,
     );
   };
 
   const start: PerfLoggerAPI['start'] = (label) =>
     performance.mark(label, {
       detail: {
-        memoryUsage: process.memoryUsage(),
+        memoryUsage: getMemory(),
       },
     });
 
@@ -110,30 +125,42 @@ function createPerfLogger(): PerfLoggerAPI {
       duration,
       memory: {
         before: memoryUsage,
-        after: process.memoryUsage(),
+        after: getMemory(),
       },
+      error: undefined,
     });
   };
 
   const log: PerfLoggerAPI['log'] = (label: string) =>
-    console.log(PerfPrefix + applyParentPrefix(label));
+    console.log(`${PerfPrefix} ${applyParentPrefix(label)}`);
 
   const async: PerfLoggerAPI['async'] = async (label, asyncFn) => {
     const finalLabel = applyParentPrefix(label);
     const before = performance.now();
-    const memoryBefore = process.memoryUsage();
-    const result = await ParentPrefix.run(finalLabel, () => asyncFn());
-    const memoryAfter = process.memoryUsage();
-    const duration = performance.now() - before;
-    printPerfLog({
-      label: finalLabel,
-      duration,
-      memory: {
-        before: memoryBefore,
-        after: memoryAfter,
-      },
-    });
-    return result;
+    const memoryBefore = getMemory();
+
+    const asyncEnd = ({error}: {error: Error | undefined}) => {
+      const memoryAfter = getMemory();
+      const duration = performance.now() - before;
+      printPerfLog({
+        error,
+        label: finalLabel,
+        duration,
+        memory: {
+          before: memoryBefore,
+          after: memoryAfter,
+        },
+      });
+    };
+
+    try {
+      const result = await ParentPrefix.run(finalLabel, () => asyncFn());
+      asyncEnd({error: undefined});
+      return result;
+    } catch (e) {
+      asyncEnd({error: e as Error});
+      throw e;
+    }
   };
 
   return {

packages/docusaurus-types/src/config.d.ts

@@ -403,6 +403,7 @@ export type DocusaurusConfig = {
    *
    * @see https://docusaurus.io/docs/api/docusaurus-config#ssrTemplate
    */
+  // TODO Docusaurus v4 - rename to ssgTemplate?
   ssrTemplate?: string;
   /**
    * Will be used as title delimiter in the generated `<title>` tag.

packages/docusaurus/src/client/renderToHtml.tsx

@@ -7,74 +7,22 @@
 
 import type {ReactNode} from 'react';
 import {renderToPipeableStream} from 'react-dom/server';
-import {Writable} from 'stream';
+import {PassThrough} from 'node:stream';
+import {text} from 'node:stream/consumers';
 
+// See also https://github.com/facebook/react/issues/31134
+// See also https://github.com/facebook/docusaurus/issues/9985#issuecomment-2396367797
 export async function renderToHtml(app: ReactNode): Promise<string> {
-  // Inspired from
-  // https://react.dev/reference/react-dom/server/renderToPipeableStream#waiting-for-all-content-to-load-for-crawlers-and-static-generation
-  // https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/cache-dir/static-entry.js
-  const writableStream = new WritableAsPromise();
-
-  const {pipe} = renderToPipeableStream(app, {
-    onError(error) {
-      writableStream.destroy(error as Error);
-    },
-    onAllReady() {
-      pipe(writableStream);
-    },
-  });
-
-  return writableStream.getPromise();
-}
-
-// WritableAsPromise inspired by https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/cache-dir/server-utils/writable-as-promise.js
-
-/* eslint-disable no-underscore-dangle */
-class WritableAsPromise extends Writable {
-  private _output: string;
-  private _deferred: {
-    promise: Promise<string> | null;
-    resolve: (value: string) => void;
-    reject: (reason: Error) => void;
-  };
-
-  constructor() {
-    super();
-    this._output = ``;
-    this._deferred = {
-      promise: null,
-      resolve: () => null,
-      reject: () => null,
-    };
-    this._deferred.promise = new Promise((resolve, reject) => {
-      this._deferred.resolve = resolve;
-      this._deferred.reject = reject;
+  return new Promise((resolve, reject) => {
+    const passThrough = new PassThrough();
+    const {pipe} = renderToPipeableStream(app, {
+      onError(error) {
+        reject(error);
+      },
+      onAllReady() {
+        pipe(passThrough);
+        text(passThrough).then(resolve, reject);
+      },
     });
-  }
-
-  override _write(
-    chunk: {toString: () => string},
-    _enc: unknown,
-    next: () => void,
-  ) {
-    this._output += chunk.toString();
-    next();
-  }
-
-  override _destroy(error: Error | null, next: (error?: Error | null) => void) {
-    if (error instanceof Error) {
-      this._deferred.reject(error);
-    } else {
-      next();
-    }
-  }
-
-  override end() {
-    this._deferred.resolve(this._output);
-    return this.destroy();
-  }
-
-  getPromise(): Promise<string> {
-    return this._deferred.promise!;
-  }
+  });
 }

packages/docusaurus/src/client/serverEntry.tsx

@@ -42,7 +42,10 @@ const render: AppRenderer = async ({pathname}) => {
   const html = await renderToHtml(app);
 
   const collectedData: PageCollectedData = {
+    // TODO Docusaurus v4 refactor: helmet state is non-serializable
+    //  this makes it impossible to run SSG in a worker thread
     helmet: (helmetContext as FilledContext).helmet,
+
     anchors: statefulBrokenLinks.getCollectedAnchors(),
     links: statefulBrokenLinks.getCollectedLinks(),
     modules: Array.from(modules),