uv-export behavior

[daturkel]

Hi, thanks for this helpful pre-commit plugin.

One thing I noticed was that uv-export is marked as "passed" even if it generates a brand new requirements file. I'd expect it to only pass if it creates no new changes, and to fail (and force me to add requirements then recommit) otherwise. Is there a way to enable that behavior?

Thanks!
Dan

[danielhollas]

"passed" even if it generates a brand new requirements file.

Do you have that file checked in your repo? I think pre-commit should automatically detect if a file under version control was changed during hook execution and fail the hook accordingly. But I might be wrong...

[daturkel]

It's possible that when I first set up pre-commit I didn't have requirements.txt checked in. I do now and just tried to reproduce the issue and could not reproduce it—committing a change to the lock file triggered the uv export action, which "failed" and thus blocked the commit (adding an unstaged change to requirements for me to stage).

In that case, this may have been user error!

[ohiliazov]

I would expect the uv-export hook to run and fail if there are changes in uv.lock or .pre-commit-config.yaml, and when requirements.txt is modified:

uv-export..................................................................Failed
- hook id: uv-export
- files were modified by this hook

Initially, I thought the hook always passed incorrectly, but it turned out that requirements.txt wasn’t checked in—my mistake! However, I noticed that adding the --no-hashes argument makes the hook stop working entirely and always pass, regardless of changes.

I really love uv—it’s an amazing tool! I’d be super grateful for any insights or suggestions regarding this behavior. Thank you!

Update: To answer my own message, this is the correct way to set up the hook to use --no-hashes:

  - repo: https://github.com/astral-sh/uv-pre-commit
    rev: 0.5.29
    hooks:
      - id: uv-lock
      - id: uv-export
        args:
          - --no-hashes
          - --output-file=requirements.txt