mixed-line-ending false positive failure on Windows

Steps to reproduce:

create git repository on Windows platform add file .gitattributes with content: * text=auto setup pre-commit hook with:

mixed-line-ending
      args: ['--fix=lf']

Create text file yourfile.c with CRLF line endigs. Add it to git repository. Stage it. Commit it.

Expected result:

Mixed line ending........................................................Passed as git automatically converts CRLF to LF when commiting

Actual result:

Mixed line ending........................................................Failed
- hook id: mixed-line-ending
- exit code: 1
- files were modified by this hook

stage modified file, git warns you:

Stage 1 files
warning: LF will be replaced by CRLF in yourfile.c.
The file will have its original line endings in your working directory
Done

Commit: Mixed line ending........................................................Passed

At this point, I am not sure which line endings end up committed in repository. Probably LF, as this test passes on server running Linux which checks pull requests.

[mkbel]

Thank you for quick response. So if this is technical limitation, I would propose to document it. https://github.com/pre-commit/pre-commit-hooks/pull/437

[asottile]

that recommendation (afaik) is only due to older tools defaulting to crlf on windows – though most tools on windows work fine with just lf endings now-a-days