fix: use native git command to get .git directory

.changeset/stale-ants-hope.md

@@ -0,0 +1,5 @@
+---
+'lint-staged': patch
+---
+
+Use native "git rev-parse" commands to determine git repo root directory and the .git config directory, instead of using custom logic. This hopefully makes path resolution more robust on non-POSIX systems.

lib/resolveGitRepo.js

@@ -1,38 +1,10 @@
-import fs from 'node:fs/promises'
-import path from 'node:path'
-
 import debug from 'debug'
 
 import { execGit } from './execGit.js'
-import { readFile } from './file.js'
 import { normalizePath } from './normalizePath.js'
 
 const debugLog = debug('lint-staged:resolveGitRepo')
 
-/**
- * Resolve path to the .git directory, with special handling for
- * submodules and worktrees
- */
-const resolveGitConfigDir = async (gitDir) => {
-  // Get the real path in case it's a symlink
-  const defaultDir = path.join(gitDir, '.git')
-  const stats = await fs.lstat(defaultDir)
-
-  // If .git is a directory, use it
-  if (stats.isDirectory()) {
-    return defaultDir
-  }
-
-  // If .git is a symlink, return the real location
-  if (stats.isSymbolicLink()) {
-    return await fs.realpath(gitDir)
-  }
-
-  // Otherwise .git is a file containing path to real location
-  const file = (await readFile(defaultDir)).toString()
-  return path.resolve(gitDir, file.replace(/^gitdir: /, '')).trim()
-}
-
 /**
  * Resolve git directory and possible submodule paths
  */
@@ -49,9 +21,11 @@ export const resolveGitRepo = async (cwd = process.cwd()) => {
     const gitDir = normalizePath(
       await execGit(['rev-parse', '--path-format=absolute', '--show-toplevel'], { cwd })
     )
-    const gitConfigDir = normalizePath(await resolveGitConfigDir(gitDir))
-
     debugLog('Resolved git directory to be `%s`', gitDir)
+
+    const gitConfigDir = normalizePath(
+      await execGit(['rev-parse', '--path-format=absolute', '--absolute-git-dir'], { cwd })
+    )
     debugLog('Resolved git config directory to be `%s`', gitConfigDir)
 
     return { gitDir, gitConfigDir }