From 0372ecd1e910697f2f362a607b5fd730d8a7f9b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Lorber?= <slorber@users.noreply.github.com>
Date: Fri, 17 Oct 2025 21:02:45 +0200
Subject: [PATCH] fix(faster): fix server build SWC / browserslist node target
 (#11496)

---
 .../src/loaders/jsLoader.ts                   |  4 +-
 .../docusaurus-bundler/src/minification.ts    |  5 ++-
 packages/docusaurus-faster/package.json       |  1 +
 packages/docusaurus-faster/src/index.ts       | 41 ++++++++++++++++++-
 .../docusaurus-theme-mermaid/src/index.ts     | 12 ------
 5 files changed, 46 insertions(+), 17 deletions(-)

diff --git a/packages/docusaurus-bundler/src/loaders/jsLoader.ts b/packages/docusaurus-bundler/src/loaders/jsLoader.ts
index 6f9213454d..51d749ce64 100644
--- a/packages/docusaurus-bundler/src/loaders/jsLoader.ts
+++ b/packages/docusaurus-bundler/src/loaders/jsLoader.ts
@@ -28,7 +28,7 @@ async function createSwcJsLoaderFactory(): Promise<
   return ({isServer}) => {
     return {
       loader,
-      options: getOptions({isServer}),
+      options: getOptions({isServer, bundlerName: 'webpack'}),
     };
   };
 }
@@ -42,7 +42,7 @@ async function createRspackSwcJsLoaderFactory(): Promise<
   return ({isServer}) => {
     return {
       loader,
-      options: getOptions({isServer}),
+      options: getOptions({isServer, bundlerName: 'rspack'}),
     };
   };
 }
diff --git a/packages/docusaurus-bundler/src/minification.ts b/packages/docusaurus-bundler/src/minification.ts
index 0c4d2d8dde..a06b81c988 100644
--- a/packages/docusaurus-bundler/src/minification.ts
+++ b/packages/docusaurus-bundler/src/minification.ts
@@ -142,7 +142,10 @@ async function getRspackMinimizers({
 }: MinimizersConfig): Promise<WebpackPluginInstance[]> {
   const rspack = getCurrentBundlerAsRspack({currentBundler});
   const getBrowserslistQueries = await importGetBrowserslistQueries();
-  const browserslistQueries = getBrowserslistQueries({isServer: false});
+  const browserslistQueries = getBrowserslistQueries({
+    isServer: false,
+    bundlerName: 'rspack',
+  });
   const swcJsMinimizerOptions = await importSwcJsMinimizerOptions();
   return [
     // See https://rspack.dev/plugins/rspack/swc-js-minimizer-rspack-plugin
diff --git a/packages/docusaurus-faster/package.json b/packages/docusaurus-faster/package.json
index 704b4f08a6..23c119d216 100644
--- a/packages/docusaurus-faster/package.json
+++ b/packages/docusaurus-faster/package.json
@@ -24,6 +24,7 @@
     "@swc/html": "^1.13.5",
     "browserslist": "^4.24.2",
     "lightningcss": "^1.27.0",
+    "semver": "^7.5.4",
     "swc-loader": "^0.2.6",
     "tslib": "^2.6.0",
     "webpack": "^5.95.0"
diff --git a/packages/docusaurus-faster/src/index.ts b/packages/docusaurus-faster/src/index.ts
index cba2c68730..27cc387a7a 100644
--- a/packages/docusaurus-faster/src/index.ts
+++ b/packages/docusaurus-faster/src/index.ts
@@ -9,18 +9,22 @@ import Rspack from '@rspack/core';
 import * as lightningcss from 'lightningcss';
 import browserslist from 'browserslist';
 import {minify as swcHtmlMinifier} from '@swc/html';
+import semver from 'semver';
 import type {JsMinifyOptions, Options as SwcOptions} from '@swc/core';
+import type {CurrentBundler} from '@docusaurus/types';
 
 export const swcLoader = require.resolve('swc-loader');
 
 export const getSwcLoaderOptions = ({
   isServer,
+  bundlerName,
 }: {
   isServer: boolean;
+  bundlerName: CurrentBundler['name'];
 }): SwcOptions => {
   return {
     env: {
-      targets: getBrowserslistQueries({isServer}),
+      targets: getBrowserslistQueries({isServer, bundlerName}),
     },
     jsc: {
       parser: {
@@ -63,20 +67,53 @@ export function getSwcJsMinimizerOptions(): JsMinifyOptions {
   };
 }
 
+// TODO this is not accurate
+//  for Rspack we should read from the built-in browserslist data
+//  see https://github.com/facebook/docusaurus/pull/11496
+function getLastBrowserslistKnownNodeVersion(
+  bundlerName: CurrentBundler['name'],
+): string {
+  if (bundlerName === 'rspack') {
+    // TODO hardcoded value until Rspack exposes its Browserslist data
+    //  see https://github.com/facebook/docusaurus/pull/11496
+    return '22.0.0';
+  }
+  // browserslist('last 1 node versions')[0]!.replace('node ', '')
+  return browserslist.nodeVersions.at(-1)!;
+}
+
+function getMinVersion(v1: string, v2: string): string {
+  return semver.lt(v1, v2) ? v1 : v2;
+}
+
 // We need this because of Rspack built-in LightningCSS integration
 // See https://github.com/orgs/browserslist/discussions/846
 export function getBrowserslistQueries({
   isServer,
+  bundlerName,
 }: {
   isServer: boolean;
+  bundlerName: CurrentBundler['name'];
 }): string[] {
   if (isServer) {
-    return [`node ${process.versions.node}`];
+    // Escape hatch env variable
+    if (process.env.DOCUSAURUS_SERVER_NODE_TARGET) {
+      return [`node ${process.env.DOCUSAURUS_SERVER_NODE_TARGET}`];
+    }
+    // For server builds, we want to use the current Node version as target
+    // But we can't pass a target that Browserslist doesn't know about yet
+    const nodeTarget = getMinVersion(
+      process.versions.node,
+      getLastBrowserslistKnownNodeVersion(bundlerName),
+    );
+
+    return [`node ${nodeTarget}`];
   }
 
   const queries = browserslist.loadConfig({path: process.cwd()}) ?? [
     ...browserslist.defaults,
   ];
+
   return queries;
 }
 
diff --git a/packages/docusaurus-theme-mermaid/src/index.ts b/packages/docusaurus-theme-mermaid/src/index.ts
index 288000902b..622c6b2ef7 100644
--- a/packages/docusaurus-theme-mermaid/src/index.ts
+++ b/packages/docusaurus-theme-mermaid/src/index.ts
@@ -49,18 +49,6 @@ export default async function themeMermaid(): Promise<Plugin<void>> {
             ),
           }),
         ],
-
-        // Workaround for weird Rspack/SWC issue
-        // See https://github.com/facebook/docusaurus/issues/11430
-        resolve: {
-          alias: {
-            ...(elkLayoutEnabled
-              ? {}
-              : {
-                  '@mermaid-js/layout-elk': false,
-                }),
-          },
-        },
       };
     },
   };