fix: gracefully handle forbidden filesystem access

packages/vite/src/node/__tests__/utils.spec.ts

@@ -1,10 +1,12 @@
+import fs from 'node:fs'
 import { describe, expect, test } from 'vitest'
 import {
   asyncFlatten,
   getHash,
   getLocalhostAddressIfDiffersFromDNS,
   getPotentialTsSrcPaths,
   injectQuery,
+  isFileReadable,
   isWindows,
   posToNumber,
   resolveHostname
@@ -236,3 +238,28 @@ describe('asyncFlatten', () => {
     expect(arr).toEqual([1, 2, 3, 4, 5, 6, 7, 8, 9])
   })
 })
+
+describe('isFileReadable', () => {
+  test("file doesn't exist", async () => {
+    expect(isFileReadable('/does_not_exist')).toBe(false)
+  })
+
+  const testFile = require.resolve(
+    './utils/isFileReadable/permission-test-file'
+  )
+  test('file with normal permission', async () => {
+    expect(isFileReadable(testFile)).toBe(true)
+  })
+
+  if (process.platform !== 'win32') {
+    test('file with read-only permission', async () => {
+      fs.chmodSync(testFile, '400')
+      expect(isFileReadable(testFile)).toBe(true)
+    })
+    test('file without read permission', async () => {
+      fs.chmodSync(testFile, '044')
+      expect(isFileReadable(testFile)).toBe(false)
+      fs.chmodSync(testFile, '644')
+    })
+  }
+})

packages/vite/src/node/plugins/resolve.ts

@@ -531,9 +531,6 @@ function tryResolveFile(
   tryPrefix?: string,
   skipPackageJson?: boolean
 ): string | undefined {
-  // #2051 if we don't have read permission on a directory, existsSync() still
-  // works and will result in massively slow subsequent checks (which are
-  // unnecessary in the first place)
   if (isFileReadable(file)) {
     if (!fs.statSync(file).isDirectory()) {
       return getRealPath(file, options.preserveSymlinks) + postfix

packages/vite/src/node/utils.ts

@@ -535,16 +535,10 @@ export function writeFile(
   fs.writeFileSync(filename, content)
 }
 
-/**
- * Use fs.statSync(filename) instead of fs.existsSync(filename)
- * #2051 if we don't have read permission on a directory, existsSync() still
- * works and will result in massively slow subsequent checks (which are
- * unnecessary in the first place)
- */
 export function isFileReadable(filename: string): boolean {
   try {
-    const stat = fs.statSync(filename, { throwIfNoEntry: false })
-    return !!stat
+    fs.accessSync(filename, fs.constants.R_OK)
+    return true
   } catch {
     return false
   }