From cc9bc2131d471bb4d60364614b326ada3ca7d10d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=BF=A0?= <green@sapphi.red>
Date: Tue, 27 Oct 2026 16:59:41 +0900
Subject: [PATCH] fix(optimizer): detect cache dir precisely (#23912)

---
 .../node/__tests__/optimizer/cacheDir.spec.ts | 54 +++++++++++++++++++
 packages/vite/src/node/optimizer/index.ts     | 10 ++--
 2 files changed, 60 insertions(+), 4 deletions(-)
 create mode 100644 packages/vite/src/node/__tests__/optimizer/cacheDir.spec.ts

diff --git a/packages/vite/src/node/__tests__/optimizer/cacheDir.spec.ts b/packages/vite/src/node/__tests__/optimizer/cacheDir.spec.ts
new file mode 100644
index 0000000000..372410f56d
--- /dev/null
+++ b/packages/vite/src/node/__tests__/optimizer/cacheDir.spec.ts
@@ -0,0 +1,54 @@
+import path from 'node:path'
+import { describe, expect, test } from 'vitest'
+import type { Environment } from '../../environment'
+import {
+  createIsOptimizedDepFile,
+  createIsOptimizedDepUrl,
+} from '../../optimizer'
+import { normalizePath, removeLeadingSlash } from '../../utils'
+
+const root = normalizePath(path.resolve(import.meta.dirname, '/project'))
+const cacheDir = normalizePath(path.resolve(import.meta.dirname, '/cache'))
+const environment = {
+  name: 'client',
+  config: { root, cacheDir },
+} as Environment
+const cacheDirNames = [
+  'deps',
+  'deps_ssr',
+  'deps_ssr_worker',
+  'deps_temp_123',
+  'deps-extra',
+]
+
+describe('createIsOptimizedDepFile', () => {
+  const isFile = createIsOptimizedDepFile(environment)
+
+  for (const dir of cacheDirNames) {
+    test(`classifies files in ${dir}`, () => {
+      expect(isFile(`${cacheDir}/${dir}/dep.js?v=abc`)).toBe(dir === 'deps')
+    })
+  }
+})
+
+describe('createIsOptimizedDepUrl', () => {
+  const isUrl = createIsOptimizedDepUrl(environment)
+
+  for (const dir of cacheDirNames) {
+    test(`classifies URLs in ${dir}`, () => {
+      expect(
+        isUrl(`/@fs/${removeLeadingSlash(cacheDir)}/${dir}/dep.js.map`),
+      ).toBe(dir === 'deps')
+    })
+  }
+
+  test('matches root-relative URLs when the cache is inside root', () => {
+    const isUrlInsideRoot = createIsOptimizedDepUrl({
+      name: 'client',
+      config: { root, cacheDir: `${root}/cache` },
+    } as Environment)
+
+    expect(isUrlInsideRoot('/cache/deps/dep.js')).toBe(true)
+    expect(isUrlInsideRoot('/cache/deps_other/dep.js')).toBe(false)
+  })
+})
diff --git a/packages/vite/src/node/optimizer/index.ts b/packages/vite/src/node/optimizer/index.ts
index 6e72404988..a51975abcb 100644
--- a/packages/vite/src/node/optimizer/index.ts
+++ b/packages/vite/src/node/optimizer/index.ts
@@ -14,7 +14,7 @@ import {
 } from 'rolldown'
 import { isDynamicPattern } from 'tinyglobby'
 import type { DepsOptimizerEsbuildOptions } from '#types/internal/esbuildOptions'
-import { isWindows } from '../../shared/utils'
+import { isWindows, withTrailingSlash } from '../../shared/utils'
 import type { ResolvedConfig } from '../config'
 import {
   ESBUILD_BASELINE_WIDELY_AVAILABLE_TARGET,
@@ -988,7 +988,7 @@ function getDepsCacheDirPrefix(environment: Environment): string {
 export function createIsOptimizedDepFile(
   environment: Environment,
 ): (id: string) => boolean {
-  const depsCacheDirPrefix = getDepsCacheDirPrefix(environment)
+  const depsCacheDirPrefix = withTrailingSlash(getDepsCacheDir(environment))
   return (id) => id.startsWith(depsCacheDirPrefix)
 }
 
@@ -996,8 +996,10 @@ export function createIsOptimizedDepUrl(
   environment: Environment,
 ): (url: string) => boolean {
   const { root } = environment.config
-  const depsCacheDir = getDepsCacheDirPrefix(environment)
-  const depsCacheDirPrefix = fileToModuleUrl(depsCacheDir, root)
+  const depsCacheDir = getDepsCacheDir(environment)
+  const depsCacheDirPrefix = withTrailingSlash(
+    fileToModuleUrl(depsCacheDir, root),
+  )
   return function isOptimizedDepUrl(url: string): boolean {
     return url.startsWith(depsCacheDirPrefix)
   }