fix(optimizer): map relative worker paths to correct relative file location

packages/vite/src/node/__tests__/plugins/import.spec.ts

@@ -79,13 +79,13 @@ describe('runTransform', () => {
   test('import all specifier', () => {
     expect(runTransformCjsImport('import * as react from "react"', false))
       .toMatchInlineSnapshot(`
-      "import __vite__cjsImport0_react from "./node_modules/.vite/deps/react.js";
-       const react = ((m, n) => n || !m?.__esModule ? {	...typeof m === "object" && !Array.isArray(m) || typeof m === "function" ? m : {},	default: m} : m)(__vite__cjsImport0_react, 0)"
-    `)
+        "import __vite__cjsImport0_react from "./node_modules/.vite/deps/react.js";
+         const react = ((m, n) => n || !m?.__esModule ? {  ...typeof m === "object" && !Array.isArray(m) || typeof m === "function" ? m : {},  default: m} : m)(__vite__cjsImport0_react, 0)"
+      `)
     expect(runTransformCjsImport('import * as react from "react"', true))
       .toMatchInlineSnapshot(`
         "import __vite__cjsImport0_react from "./node_modules/.vite/deps/react.js";
-         const react = ((m, n) => n || !m?.__esModule ? {	...typeof m === "object" && !Array.isArray(m) || typeof m === "function" ? m : {},	default: m} : m)(__vite__cjsImport0_react, 1)"
+         const react = ((m, n) => n || !m?.__esModule ? {  ...typeof m === "object" && !Array.isArray(m) || typeof m === "function" ? m : {},  default: m} : m)(__vite__cjsImport0_react, 1)"
       `)
   })
 

packages/vite/src/node/optimizer/rolldownDepPlugin.ts

@@ -1,6 +1,7 @@
 import path from 'node:path'
 import type { ImportKind, Plugin, RolldownPlugin } from 'rolldown'
 import { prefixRegex } from '@rolldown/pluginutils'
+import MagicString from 'magic-string'
 import { JS_TYPES_RE, KNOWN_ASSET_TYPES } from '../constants'
 import type { PackageCache } from '../packages'
 import {
@@ -11,6 +12,7 @@ import {
   isExternalUrl,
   isNodeBuiltin,
   moduleListContains,
+  normalizePath,
 } from '../utils'
 import { browserExternalId, optionalPeerDepId } from '../plugins/resolve'
 import { isModuleCSSRequest } from '../plugins/css'
@@ -298,6 +300,53 @@ export function rolldownDepPlugin(
           }
         },
       },
+      transform: {
+        filter: { code: /new\s+URL/ },
+        async handler(code, id) {
+          if (!id.includes('node_modules')) return null
+
+          const s = new MagicString(code)
+
+          const workerRE =
+            /new\s+URL\s*\(\s*['"]([^'"]+)['"]\s*,\s*import\.meta\.url\s*\)/g
+
+          // Optimized dependencies are always written to the 'deps' sub-directory
+          // within the configured cache directory.
+          const bundleDir = path.join(environment.config.cacheDir, 'deps')
+
+          let hasReplacements = false
+          let match
+          while ((match = workerRE.exec(code))) {
+            hasReplacements = true
+            const [fullMatch, url] = match
+            const absolutePath = path.resolve(path.dirname(id), url)
+            const relativePath = path.relative(bundleDir, absolutePath)
+            const normalizedRelativePath = normalizePath(relativePath)
+
+            // NOTE: add `'' +` to opt-out rolldown's transform: https://github.com/rolldown/rolldown/issues/2745
+            const replacement = `new URL('' + ${JSON.stringify(normalizedRelativePath)}, import.meta.url)`
+
+            s.overwrite(
+              match.index,
+              match.index + fullMatch.length,
+              replacement,
+            )
+
+            const assetDir = path.dirname(absolutePath)
+
+            if (
+              environment.config.server.fs.allow &&
+              !environment.config.server.fs.allow.includes(assetDir)
+            ) {
+              environment.config.server.fs.allow.push(assetDir)
+            }
+          }
+
+          if (!hasReplacements) return null
+
+          return { code: s.toString(), map: s.generateMap({ hires: true }) }
+        },
+      },
     },
   ]
 }

playground/optimize-deps/__tests__/optimize-deps.spec.ts

@@ -1,3 +1,5 @@
+import fs from 'node:fs'
+import path from 'node:path'
 import { describe, expect, test } from 'vitest'
 import {
   browserErrors,
@@ -370,3 +372,41 @@ test.runIf(isServe)(
     expect(scanErrors).toHaveLength(0)
   },
 )
+
+test('should fix standard web worker URLs in optimized dependencies', async () => {
+  await expect
+    .poll(() => browserLogs.join('\n'))
+    .toMatch(/Message from lib: worker-success/)
+  await expect
+    .poll(() => browserLogs.join('\n'))
+    .toMatch(/Message from nested: worker-success/)
+
+  if (isServe) {
+    const playgroundDir = path.resolve(__dirname, '..')
+    const depsDir = path.join(playgroundDir, 'node_modules', '.vite', 'deps')
+
+    const files = fs.readdirSync(depsDir)
+    const workerReproFile = files.find(
+      (f) => f.includes('test-dep-with-worker-repro') && f.endsWith('.js'),
+    )
+
+    if (!workerReproFile) {
+      throw new Error(
+        `Could not find optimized bundle for worker repro in ${depsDir}. Available files: ${files.join(', ')}`,
+      )
+    }
+
+    const content = fs.readFileSync(
+      path.join(depsDir, workerReproFile),
+      'utf-8',
+    )
+
+    const urlContentMatch = content.match(/new URL\('' \+ "([^"]+)"/)
+    const innerUrl = urlContentMatch ? urlContentMatch[1] : ''
+
+    expect(innerUrl, `Path "${innerUrl}" should not be absolute`).not.toMatch(
+      /^\/|^[a-zA-Z]:\\|^\\\\/,
+    )
+    expect(innerUrl).toMatch(/^\.\.\//)
+  }
+})

playground/optimize-deps/dep-with-worker-repro/index.js

@@ -0,0 +1,8 @@
+export function urlImportWorker() {
+  const worker = new Worker(new URL('./worker.js', import.meta.url), {
+    type: 'module',
+  })
+  return new Promise((res) => {
+    worker.onmessage = (e) => res(e.data)
+  })
+}

playground/optimize-deps/dep-with-worker-repro/nested/index.js

@@ -0,0 +1,9 @@
+export function urlImportWorker() {
+  // Testing the ../ path traversal
+  const worker = new Worker(new URL('../worker.js', import.meta.url), {
+    type: 'module',
+  })
+  return new Promise((res) => {
+    worker.onmessage = (e) => res(e.data)
+  })
+}

playground/optimize-deps/dep-with-worker-repro/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@vitejs/test-dep-with-worker-repro",
+  "version": "1.0.0",
+  "type": "module",
+  "exports": {
+    ".": "./index.js",
+    "./nested": "./nested/index.js"
+  }
+}

playground/optimize-deps/dep-with-worker-repro/worker.js

@@ -0,0 +1 @@
+self.postMessage('worker-success')

playground/optimize-deps/index.html

@@ -386,3 +386,10 @@ <h2>Virtual module with .vue extension</h2>
     `${VirtualComponent.name === 'VirtualComponent' ? 'ok' : 'ng'}`,
   )
 </script>
+<script type="module">
+  import * as lib from '@vitejs/test-dep-with-worker-repro'
+  import * as nested from '@vitejs/test-dep-with-worker-repro/nested'
+
+  lib.urlImportWorker().then((m) => console.log('Message from lib:', m))
+  nested.urlImportWorker().then((m) => console.log('Message from nested:', m))
+</script>

playground/optimize-deps/package.json

@@ -42,6 +42,7 @@
     "@vitejs/test-dep-non-optimized": "file:./dep-non-optimized",
     "@vitejs/test-added-in-entries": "file:./added-in-entries",
     "@vitejs/test-dep-cjs-external-package-omit-js-suffix": "file:./dep-cjs-external-package-omit-js-suffix",
+    "@vitejs/test-dep-with-worker-repro": "file:./dep-with-worker-repro",
     "lodash-es": "^4.17.22",
     "@vitejs/test-nested-exclude": "file:./nested-exclude",
     "phoenix": "^1.8.3",