From 8e69a7976379910ea417e6565ca44397e4a3d2e2 Mon Sep 17 00:00:00 2001
From: Charan Rathore <141534082+charan-rathore@users.noreply.github.com>
Date: Sat, 26 Sep 2026 13:16:07 +0530
Subject: [PATCH 1/2] fix: keep browser:false modules empty in dependency
 optimizer

---
 .../vite/src/node/optimizer/rolldownDepPlugin.ts   | 10 ++++++++++
 .../optimize-deps/__tests__/optimize-deps.spec.ts  | 14 ++++++++++++++
 .../optimize-deps/dep-browser-false/index.js       |  4 ++++
 .../optimize-deps/dep-browser-false/package.json   |  9 +++++++++
 playground/optimize-deps/index.html                |  6 ++++++
 playground/optimize-deps/package.json              |  1 +
 pnpm-lock.yaml                                     | 10 ++++++++++
 7 files changed, 54 insertions(+)
 create mode 100644 playground/optimize-deps/dep-browser-false/index.js
 create mode 100644 playground/optimize-deps/dep-browser-false/package.json

diff --git a/packages/vite/src/node/optimizer/rolldownDepPlugin.ts b/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
index 07d8cab4566b40..3ee461584aea35 100644
--- a/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
+++ b/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
@@ -58,6 +58,7 @@ const externalTypes = [
 
 const optionalPeerDepNamespace = 'optional-peer-dep:'
 const browserExternalNamespace = 'browser-external:'
+const browserExternalEmptyNamespace = 'browser-external-empty:'
 
 export function rolldownDepPlugin(
   environment: Environment,
@@ -121,6 +122,11 @@ export function rolldownDepPlugin(
   }
 
   const resolveResult = (id: string, resolved: string, kind: ImportKind) => {
+    // An exact browser-external id is an explicit browser:false mapping.
+    // Suffixed ids are unsupported Node builtins and still need the warning.
+    if (resolved === browserExternalId) {
+      return { id: browserExternalEmptyNamespace + id }
+    }
     if (resolved.startsWith(browserExternalId)) {
       return {
         id: browserExternalNamespace + id,
@@ -255,11 +261,15 @@ export function rolldownDepPlugin(
       load: {
         filter: {
           id: [
+            prefixRegex(browserExternalEmptyNamespace),
             prefixRegex(browserExternalNamespace),
             prefixRegex(optionalPeerDepNamespace),
           ],
         },
         handler(id) {
+          if (id.startsWith(browserExternalEmptyNamespace)) {
+            return { code: 'module.exports = {}' }
+          }
           if (id.startsWith(browserExternalNamespace)) {
             const path = id.slice(browserExternalNamespace.length)
             if (isProduction) {
diff --git a/playground/optimize-deps/__tests__/optimize-deps.spec.ts b/playground/optimize-deps/__tests__/optimize-deps.spec.ts
index d6febaafad2c17..7754b0e1887e27 100644
--- a/playground/optimize-deps/__tests__/optimize-deps.spec.ts
+++ b/playground/optimize-deps/__tests__/optimize-deps.spec.ts
@@ -255,6 +255,20 @@ test('non optimized module is not duplicated', async () => {
     .toBe('from-absolute-path, from-relative-path')
 })
 
+test.runIf(isServe)(
+  'optimized browser:false is empty without warning',
+  async () => {
+    expect(await page.textContent('.browser-false-optimized')).toBe('[success]')
+    expect(browserLogs).not.toEqual(
+      expect.arrayContaining([
+        expect.stringContaining(
+          'Module "browser-false-only" has been externalized for browser compatibility',
+        ),
+      ]),
+    )
+  },
+)
+
 test.runIf(isServe)('error on builtin modules usage', () => {
   expect(browserLogs).toEqual(
     expect.arrayContaining([
diff --git a/playground/optimize-deps/dep-browser-false/index.js b/playground/optimize-deps/dep-browser-false/index.js
new file mode 100644
index 00000000000000..2c7cc4dea71645
--- /dev/null
+++ b/playground/optimize-deps/dep-browser-false/index.js
@@ -0,0 +1,4 @@
+// An explicit browser:false mapping is an empty module, not a Node builtin warning.
+// eslint-disable-next-line n/no-missing-require -- mapped to false by package browser field
+const fs = require('browser-false-only')
+module.exports = fs.readFileSync === undefined ? '[success]' : '[fail]'
diff --git a/playground/optimize-deps/dep-browser-false/package.json b/playground/optimize-deps/dep-browser-false/package.json
new file mode 100644
index 00000000000000..57732ee0c5f41c
--- /dev/null
+++ b/playground/optimize-deps/dep-browser-false/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@vitejs/test-dep-browser-false",
+  "private": true,
+  "version": "0.0.0",
+  "main": "index.js",
+  "browser": {
+    "browser-false-only": false
+  }
+}
diff --git a/playground/optimize-deps/index.html b/playground/optimize-deps/index.html
index 2e3b6607dabff7..6f351818c61a1b 100644
--- a/playground/optimize-deps/index.html
+++ b/playground/optimize-deps/index.html
@@ -336,6 +336,12 @@ <h2>Import the CommonJS external package that omits the js suffix</h2>
   }
 </script>
 
+<p class="browser-false-optimized">[pending]</p>
+<script type="module">
+  import browserFalse from '@vitejs/test-dep-browser-false'
+  text('.browser-false-optimized', browserFalse)
+</script>
+
 <script type="module">
   // should error on builtin modules from dep
   import { read } from '@vitejs/test-dep-with-builtin-module-cjs'
diff --git a/playground/optimize-deps/package.json b/playground/optimize-deps/package.json
index 1895c50cccd1d5..344858adbd924d 100644
--- a/playground/optimize-deps/package.json
+++ b/playground/optimize-deps/package.json
@@ -39,6 +39,7 @@
     "@vitejs/test-dep-with-asset-ext1.pdf": "file:./dep-with-asset-ext/dep1",
     "@vitejs/test-dep-with-asset-ext2.pdf": "file:./dep-with-asset-ext/dep2",
     "@vitejs/test-dep-with-builtin-module-cjs": "file:./dep-with-builtin-module-cjs",
+    "@vitejs/test-dep-browser-false": "file:./dep-browser-false",
     "@vitejs/test-dep-with-builtin-module-esm": "file:./dep-with-builtin-module-esm",
     "@vitejs/test-dep-with-dynamic-import": "file:./dep-with-dynamic-import",
     "@vitejs/test-dep-with-optional-peer-dep": "file:./dep-with-optional-peer-dep",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3ab7eda3ba8254..ae7e40e72a5e0d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1234,6 +1234,9 @@ importers:
       '@vitejs/test-dep-alias-using-absolute-path':
         specifier: file:./dep-alias-using-absolute-path
         version: file:playground/optimize-deps/dep-alias-using-absolute-path
+      '@vitejs/test-dep-browser-false':
+        specifier: file:./dep-browser-false
+        version: file:playground/optimize-deps/dep-browser-false
       '@vitejs/test-dep-cjs-browser-field':
         specifier: file:./dep-cjs-browser-field
         version: file:playground/optimize-deps/dep-cjs-browser-field
@@ -1402,6 +1405,8 @@ importers:
         specifier: file:../dep-lodash
         version: file:playground/optimize-deps/dep-lodash
 
+  playground/optimize-deps/dep-browser-false: {}
+
   playground/optimize-deps/dep-cjs-browser-field: {}
 
   playground/optimize-deps/dep-cjs-browser-field-bare: {}
@@ -4697,6 +4702,9 @@ packages:
   '@vitejs/test-dep-alias-using-absolute-path@file:playground/optimize-deps/dep-alias-using-absolute-path':
     resolution: {directory: playground/optimize-deps/dep-alias-using-absolute-path, type: directory}
 
+  '@vitejs/test-dep-browser-false@file:playground/optimize-deps/dep-browser-false':
+    resolution: {directory: playground/optimize-deps/dep-browser-false, type: directory}
+
   '@vitejs/test-dep-cjs-browser-field-bare@file:playground/optimize-deps/dep-cjs-browser-field-bare':
     resolution: {directory: playground/optimize-deps/dep-cjs-browser-field-bare, type: directory}
 
@@ -10895,6 +10903,8 @@ snapshots:
     dependencies:
       '@vitejs/test-dep-lodash': file:playground/optimize-deps/dep-lodash
 
+  '@vitejs/test-dep-browser-false@file:playground/optimize-deps/dep-browser-false': {}
+
   '@vitejs/test-dep-cjs-browser-field-bare@file:playground/optimize-deps/dep-cjs-browser-field-bare': {}
 
   '@vitejs/test-dep-cjs-browser-field@file:playground/optimize-deps/dep-cjs-browser-field': {}

From 55869ef55d518059b13ac883c21189b0e736bc27 Mon Sep 17 00:00:00 2001
From: sapphi-red <green@sapphi.red>
Date: Wed, 30 Sep 2026 13:06:26 +0900
Subject: [PATCH 2/2] refactor: align with
 https://github.com/rolldown/rolldown/pull/10082

---
 packages/vite/src/node/optimizer/rolldownDepPlugin.ts | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/packages/vite/src/node/optimizer/rolldownDepPlugin.ts b/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
index 3ee461584aea35..8a0015790f95cf 100644
--- a/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
+++ b/packages/vite/src/node/optimizer/rolldownDepPlugin.ts
@@ -1,7 +1,7 @@
 import path from 'node:path'
 import MagicString from 'magic-string'
 import type { ImportKind, Plugin, RolldownPlugin } from 'rolldown'
-import { prefixRegex } from 'rolldown/filter'
+import { exactRegex, prefixRegex } from 'rolldown/filter'
 import { stripLiteral } from 'strip-literal'
 import { isWindows } from '../../shared/utils'
 import { JS_TYPES_RE, KNOWN_ASSET_TYPES } from '../constants'
@@ -58,7 +58,6 @@ const externalTypes = [
 
 const optionalPeerDepNamespace = 'optional-peer-dep:'
 const browserExternalNamespace = 'browser-external:'
-const browserExternalEmptyNamespace = 'browser-external-empty:'
 
 export function rolldownDepPlugin(
   environment: Environment,
@@ -125,7 +124,7 @@ export function rolldownDepPlugin(
     // An exact browser-external id is an explicit browser:false mapping.
     // Suffixed ids are unsupported Node builtins and still need the warning.
     if (resolved === browserExternalId) {
-      return { id: browserExternalEmptyNamespace + id }
+      return { id: browserExternalId }
     }
     if (resolved.startsWith(browserExternalId)) {
       return {
@@ -261,13 +260,13 @@ export function rolldownDepPlugin(
       load: {
         filter: {
           id: [
-            prefixRegex(browserExternalEmptyNamespace),
+            exactRegex(browserExternalId),
             prefixRegex(browserExternalNamespace),
             prefixRegex(optionalPeerDepNamespace),
           ],
         },
         handler(id) {
-          if (id.startsWith(browserExternalEmptyNamespace)) {
+          if (id === browserExternalId) {
             return { code: 'module.exports = {}' }
           }
           if (id.startsWith(browserExternalNamespace)) {