[eslint-changed] Fatal error on Windows when using `--git`

[rznn7]

Impacted plugin

None / Other

Quick summary

The package fails on Windows systems when running with --git options, throwing a fatal Git error about paths existing on disk but not in the index.

Environment

• OS: Windows (confirmed on 2 different laptops)
• Package version: 2.1.4
• Git: Git CLI (native Windows installation)
• Context: Running via lint-staged in a pre-commit hook

Trace (run with lint-staged)

✔ Backed up original state in git stash (9bbcfe76e)
⚠ Running tasks for staged files...
  ❯ lint-staged.config.mjs — 1 file
    ❯ *.ts — 1 file
      ✔ node scripts/eslint-fix-silent.js
      ✖ npx @automattic/eslint-changed --git --ext .ts [FAILED]
      ◼ prettier --write
    ↓ *.html — no files
    ↓ *.{json,css,scss,md} — no files
↓ Skipped because of errors from tasks.
✔ Reverting to original state because of errors...
✔ Cleaning up temporary files...
 
✖ npx @automattic/eslint-changed --git --ext .ts:
fatal: path 'app\src\app\path\to\file.ts' exists on disk, but not in the index
error: git exited with status 128
Error: lint-staged failed
husky - pre-commit script failed (code 1)

Steps to reproduce

1. On a Windows system, create or modify a TypeScript file in a Git repository
2. Stage the file: git add path/to/file.ts
3. Run the command: npx @automattic/eslint-changed --git --git-unstaged --ext .ts

Expected Behavior

The tool should successfully lint the staged changes without errors, as it does on Linux.

Actual Behavior

The command fails with:

fatal: path 'app\src\app\path\to\file.ts' exists on disk, but not in the index
error: git exited with status 128

Site owner impact

Fewer than 20% of the total website/platform users

Severity

Minor

What other impact(s) does this issue have?

No revenue impact

Additional information

• The same setup works perfectly on Linux
• The error specifically occurs when Git is asked to interact with a path that uses Windows-style backslashes (\)
• Git on Windows uses forward slashes (/) in its output, but the error message shows the path with backslashes
• This suggests a path separator normalization issue between Git's output format and Windows file system operations

Platform (Simple and/or Atomic)

No response

[anomiex]

I don't have access to Windows, so I'm unable to test this.

The error message quoted is from git itself, but it's not clear which git command it was trying to run. You might try running it with the --debug flag to get some additional output.