refactor(core): improve handling of server bundle

.gitignore

@@ -38,6 +38,8 @@ website/_dogfooding/_swizzle_theme_tests
 
 CrowdinTranslations_*.zip
 
+website/.cpu-prof
+
 website/i18n/**/*
 #!website/i18n/fr
 #!website/i18n/fr/**/*

package.json

@@ -28,6 +28,7 @@
     "build:website:deployPreview:build": "cross-env NETLIFY=true CONTEXT='deploy-preview' yarn workspace website build",
     "build:website:deployPreview": "yarn build:website:deployPreview:testWrap && yarn build:website:deployPreview:build",
     "build:website:fast": "yarn workspace website build:fast",
+    "build:website:fast:profile": "yarn workspace website build:fast:profile",
     "build:website:en": "yarn workspace website build --locale en",
     "clear:website": "yarn workspace website clear",
     "serve:website": "yarn workspace website serve",

packages/docusaurus-mdx-loader/src/loader.ts

@@ -28,10 +28,6 @@ import type {LoaderContext} from 'webpack';
 // See https://github.com/microsoft/TypeScript/issues/49721#issuecomment-1517839391
 type Pluggable = any; // TODO fix this asap
 
-const {
-  loaders: {inlineMarkdownAssetImageFileLoader},
-} = getFileLoaderUtils();
-
 export type MDXPlugin = Pluggable;
 
 export type Options = Partial<MDXOptions> & {
@@ -72,7 +68,13 @@ async function readMetadataPath(metadataPath: string) {
  *
  * `{image: "./myImage.png"}` => `{image: require("./myImage.png")}`
  */
-function createAssetsExportCode(assets: unknown) {
+function createAssetsExportCode({
+  assets,
+  inlineMarkdownAssetImageFileLoader,
+}: {
+  assets: unknown;
+  inlineMarkdownAssetImageFileLoader: string;
+}) {
   if (
     typeof assets !== 'object' ||
     !assets ||
@@ -245,13 +247,23 @@ ${JSON.stringify(frontMatter, null, 2)}`;
       ? options.createAssets({frontMatter, metadata})
       : undefined;
 
+  const fileLoaderUtils = getFileLoaderUtils(compilerName === 'server');
+
   // TODO use remark plugins to insert extra exports instead of string concat?
   // cf how the toc is exported
   const exportsCode = `
 export const frontMatter = ${stringifyObject(frontMatter)};
 export const contentTitle = ${stringifyObject(contentTitle)};
 ${metadataJsonString ? `export const metadata = ${metadataJsonString};` : ''}
-${assets ? `export const assets = ${createAssetsExportCode(assets)};` : ''}
+${
+  assets
+    ? `export const assets = ${createAssetsExportCode({
+        assets,
+        inlineMarkdownAssetImageFileLoader:
+          fileLoaderUtils.loaders.inlineMarkdownAssetImageFileLoader,
+      })};`
+    : ''
+}
 `;
 
   const code = `

packages/docusaurus-mdx-loader/src/remark/transformImage/index.ts

@@ -13,8 +13,8 @@ import {
   toMessageRelativeFilePath,
   posixPath,
   escapePath,
-  getFileLoaderUtils,
   findAsyncSequential,
+  getFileLoaderUtils,
 } from '@docusaurus/utils';
 import escapeHtml from 'escape-html';
 import sizeOf from 'image-size';
@@ -27,39 +27,36 @@ import type {MdxJsxTextElement} from 'mdast-util-mdx';
 import type {Image} from 'mdast';
 import type {Parent} from 'unist';
 
-const {
-  loaders: {inlineMarkdownImageFileLoader},
-} = getFileLoaderUtils();
-
 type PluginOptions = {
   staticDirs: string[];
   siteDir: string;
 };
 
 type Context = PluginOptions & {
   filePath: string;
+  inlineMarkdownImageFileLoader: string;
 };
 
 type Target = [node: Image, index: number, parent: Parent];
 
 async function toImageRequireNode(
   [node]: Target,
   imagePath: string,
-  filePath: string,
+  context: Context,
 ) {
   // MdxJsxTextElement => see https://github.com/facebook/docusaurus/pull/8288#discussion_r1125871405
   const jsxNode = node as unknown as MdxJsxTextElement;
   const attributes: MdxJsxTextElement['attributes'] = [];
 
   let relativeImagePath = posixPath(
-    path.relative(path.dirname(filePath), imagePath),
+    path.relative(path.dirname(context.filePath), imagePath),
   );
   relativeImagePath = `./${relativeImagePath}`;
 
   const parsedUrl = url.parse(node.url);
   const hash = parsedUrl.hash ?? '';
   const search = parsedUrl.search ?? '';
-  const requireString = `${inlineMarkdownImageFileLoader}${
+  const requireString = `${context.inlineMarkdownImageFileLoader}${
     escapePath(relativeImagePath) + search
   }`;
   if (node.alt) {
@@ -186,21 +183,26 @@ async function processImageNode(target: Target, context: Context) {
   // We try to convert image urls without protocol to images with require calls
   // going through webpack ensures that image assets exist at build time
   const imagePath = await getImageAbsolutePath(parsedUrl.pathname, context);
-  await toImageRequireNode(target, imagePath, context.filePath);
+  await toImageRequireNode(target, imagePath, context);
 }
 
 export default function plugin(options: PluginOptions): Transformer {
   return async (root, vfile) => {
     const {visit} = await import('unist-util-visit');
 
+    const fileLoaderUtils = getFileLoaderUtils(
+      vfile.data.compilerName === 'server',
+    );
+    const context: Context = {
+      ...options,
+      filePath: vfile.path!,
+      inlineMarkdownImageFileLoader:
+        fileLoaderUtils.loaders.inlineMarkdownImageFileLoader,
+    };
+
     const promises: Promise<void>[] = [];
     visit(root, 'image', (node: Image, index, parent) => {
-      promises.push(
-        processImageNode([node, index, parent!], {
-          ...options,
-          filePath: vfile.path!,
-        }),
-      );
+      promises.push(processImageNode([node, index, parent!], context));
     });
     await Promise.all(promises);
   };

packages/docusaurus-mdx-loader/src/remark/transformLinks/index.ts

@@ -12,8 +12,8 @@ import {
   toMessageRelativeFilePath,
   posixPath,
   escapePath,
-  getFileLoaderUtils,
   findAsyncSequential,
+  getFileLoaderUtils,
 } from '@docusaurus/utils';
 import escapeHtml from 'escape-html';
 import {assetRequireAttributeValue, transformNode} from '../utils';
@@ -24,17 +24,14 @@ import type {MdxJsxTextElement} from 'mdast-util-mdx';
 import type {Parent} from 'unist';
 import type {Link, Literal} from 'mdast';
 
-const {
-  loaders: {inlineMarkdownLinkFileLoader},
-} = getFileLoaderUtils();
-
 type PluginOptions = {
   staticDirs: string[];
   siteDir: string;
 };
 
 type Context = PluginOptions & {
   filePath: string;
+  inlineMarkdownLinkFileLoader: string;
 };
 
 type Target = [node: Link, index: number, parent: Parent];
@@ -45,15 +42,15 @@ type Target = [node: Link, index: number, parent: Parent];
 async function toAssetRequireNode(
   [node]: Target,
   assetPath: string,
-  filePath: string,
+  context: Context,
 ) {
   // MdxJsxTextElement => see https://github.com/facebook/docusaurus/pull/8288#discussion_r1125871405
   const jsxNode = node as unknown as MdxJsxTextElement;
   const attributes: MdxJsxTextElement['attributes'] = [];
 
   // require("assets/file.pdf") means requiring from a package called assets
   const relativeAssetPath = `./${posixPath(
-    path.relative(path.dirname(filePath), assetPath),
+    path.relative(path.dirname(context.filePath), assetPath),
   )}`;
 
   const parsedUrl = url.parse(node.url);
@@ -65,7 +62,9 @@ async function toAssetRequireNode(
     path.extname(relativeAssetPath) === '.json'
       ? `${relativeAssetPath.replace('.json', '.raw')}!=`
       : ''
-  }${inlineMarkdownLinkFileLoader}${escapePath(relativeAssetPath) + search}`;
+  }${context.inlineMarkdownLinkFileLoader}${
+    escapePath(relativeAssetPath) + search
+  }`;
 
   attributes.push({
     type: 'mdxJsxAttribute',
@@ -196,22 +195,27 @@ async function processLinkNode(target: Target, context: Context) {
     context,
   );
   if (assetPath) {
-    await toAssetRequireNode(target, assetPath, context.filePath);
+    await toAssetRequireNode(target, assetPath, context);
   }
 }
 
 export default function plugin(options: PluginOptions): Transformer {
   return async (root, vfile) => {
     const {visit} = await import('unist-util-visit');
 
+    const fileLoaderUtils = getFileLoaderUtils(
+      vfile.data.compilerName === 'server',
+    );
+    const context: Context = {
+      ...options,
+      filePath: vfile.path!,
+      inlineMarkdownLinkFileLoader:
+        fileLoaderUtils.loaders.inlineMarkdownLinkFileLoader,
+    };
+
     const promises: Promise<void>[] = [];
     visit(root, 'link', (node: Link, index, parent) => {
-      promises.push(
-        processLinkNode([node, index, parent!], {
-          ...options,
-          filePath: vfile.path!,
-        }),
-      );
+      promises.push(processLinkNode([node, index, parent!], context));
     });
     await Promise.all(promises);
   };

packages/docusaurus-utils/src/webpackUtils.ts

@@ -50,12 +50,13 @@ type FileLoaderUtils = {
   };
 };
 
-/**
- * Returns unified loader configurations to be used for various file types.
- *
- * Inspired by https://github.com/gatsbyjs/gatsby/blob/8e6e021014da310b9cc7d02e58c9b3efe938c665/packages/gatsby/src/utils/webpack-utils.ts#L447
- */
-export function getFileLoaderUtils(): FileLoaderUtils {
+// TODO this historical code is quite messy
+//  We should try to get rid of it and move to assets pipeline
+function createFileLoaderUtils({
+  isServer,
+}: {
+  isServer: boolean;
+}): FileLoaderUtils {
   // Files/images < urlLoaderLimit will be inlined as base64 strings directly in
   // the html
   const urlLoaderLimit = WEBPACK_URL_LOADER_LIMIT;
@@ -72,6 +73,7 @@ export function getFileLoaderUtils(): FileLoaderUtils {
       loader: require.resolve(`file-loader`),
       options: {
         name: fileLoaderFileName(options.folder),
+        emitFile: !isServer,
       },
     }),
     url: (options: {folder: AssetFolder}) => ({
@@ -80,6 +82,7 @@ export function getFileLoaderUtils(): FileLoaderUtils {
         limit: urlLoaderLimit,
         name: fileLoaderFileName(options.folder),
         fallback: require.resolve('file-loader'),
+        emitFile: !isServer,
       },
     }),
 
@@ -92,13 +95,19 @@ export function getFileLoaderUtils(): FileLoaderUtils {
       require.resolve('url-loader'),
     )}?limit=${urlLoaderLimit}&name=${fileLoaderFileName(
       'images',
-    )}&fallback=${escapePath(require.resolve('file-loader'))}!`,
+    )}&fallback=${escapePath(require.resolve('file-loader'))}${
+      isServer ? `&emitFile=false` : ''
+    }!`,
     inlineMarkdownAssetImageFileLoader: `!${escapePath(
       require.resolve('file-loader'),
-    )}?name=${fileLoaderFileName('images')}!`,
+    )}?name=${fileLoaderFileName('images')}${
+      isServer ? `&emitFile=false` : ''
+    }!`,
     inlineMarkdownLinkFileLoader: `!${escapePath(
       require.resolve('file-loader'),
-    )}?name=${fileLoaderFileName('files')}!`,
+    )}?name=${fileLoaderFileName('files')}${
+      isServer ? `&emitFile=false` : ''
+    }!`,
   };
 
   const rules: FileLoaderUtils['rules'] = {
@@ -173,3 +182,16 @@ export function getFileLoaderUtils(): FileLoaderUtils {
 
   return {loaders, rules};
 }
+
+const FileLoaderUtilsMap = {
+  server: createFileLoaderUtils({isServer: true}),
+  client: createFileLoaderUtils({isServer: false}),
+};
+
+/**
+ * Returns unified loader configurations to be used for various file types.
+ * Inspired by https://github.com/gatsbyjs/gatsby/blob/8e6e021014da310b9cc7d02e58c9b3efe938c665/packages/gatsby/src/utils/webpack-utils.ts#L447
+ */
+export function getFileLoaderUtils(isServer: boolean): FileLoaderUtils {
+  return isServer ? FileLoaderUtilsMap.server : FileLoaderUtilsMap.client;
+}

packages/docusaurus/src/commands/build.ts

@@ -196,10 +196,7 @@ async function buildLocale({
     }),
   );
 
-  // Remove server.bundle.js because it is not needed.
-  await PerfLogger.async('Deleting server bundle', () =>
-    ensureUnlink(serverBundlePath),
-  );
+  await cleanupServerBundle(serverBundlePath);
 
   // Plugin Lifecycle - postBuild.
   await PerfLogger.async('postBuild()', () =>
@@ -361,8 +358,17 @@ async function getBuildServerConfig({props}: {props: Props}) {
   return {serverConfig: config, serverBundlePath: result.serverBundlePath};
 }
 
-async function ensureUnlink(filepath: string) {
-  if (await fs.pathExists(filepath)) {
-    await fs.unlink(filepath);
+// Remove /build/server server.bundle.js because it is not needed.
+async function cleanupServerBundle(serverBundlePath: string) {
+  if (process.env.DOCUSAURUS_KEEP_SERVER_BUNDLE === 'true') {
+    logger.warn(
+      "Will NOT delete server bundle because DOCUSAURUS_KEEP_SERVER_BUNDLE is set to 'true'",
+    );
+  } else {
+    await PerfLogger.async('Deleting server bundle', async () => {
+      // For now we assume server entry is at the root of the server out dir
+      const serverDir = path.dirname(serverBundlePath);
+      await fs.rm(serverDir, {recursive: true, force: true});
+    });
   }
 }

packages/docusaurus/src/webpack/base.ts

@@ -77,7 +77,7 @@ export async function createBaseConfig({
   const isProd = process.env.NODE_ENV === 'production';
   const minimizeEnabled = minify && isProd;
 
-  const fileLoaderUtils = getFileLoaderUtils();
+  const fileLoaderUtils = getFileLoaderUtils(isServer);
 
   const name = isServer ? 'server' : 'client';
   const mode = isProd ? 'production' : 'development';

packages/docusaurus/src/webpack/server.ts

@@ -27,14 +27,16 @@ export default async function createServerConfig(params: {
   });
 
   const outputFilename = 'server.bundle.js';
-  const serverBundlePath = path.join(props.outDir, outputFilename);
+  const outputDir = path.join(props.outDir, '__server');
+  const serverBundlePath = path.join(outputDir, outputFilename);
 
   const config = merge(baseConfig, {
     target: `node${NODE_MAJOR_VERSION}.${NODE_MINOR_VERSION}`,
     entry: {
       main: path.resolve(__dirname, '../client/serverEntry.js'),
     },
     output: {
+      path: outputDir,
       filename: outputFilename,
       libraryTarget: 'commonjs2',
       // Workaround for Webpack 4 Bug (https://github.com/webpack/webpack/issues/6522)

website/package.json

@@ -22,6 +22,7 @@
     "start:blogOnly": "cross-env yarn start --config=docusaurus.config-blog-only.js",
     "build:blogOnly": "cross-env yarn build --config=docusaurus.config-blog-only.js",
     "build:fast": "cross-env BUILD_FAST=true yarn build --locale en",
+    "build:fast:profile": "cross-env BUILD_FAST=true node --cpu-prof --cpu-prof-dir .cpu-prof ./node_modules/.bin/docusaurus build --locale en",
     "netlify:build:production": "yarn docusaurus write-translations && yarn netlify:crowdin:delay && yarn netlify:crowdin:uploadSources && yarn netlify:crowdin:downloadTranslations && yarn build && yarn test:css-order",
     "netlify:build:branchDeploy": "yarn build && yarn test:css-order",
     "netlify:build:deployPreview": "yarn build && yarn test:css-order",