Run pre-commit hook with `pass_filenames: true` only once with all filenames

Question

I have a pre-commit hook running a local executable and I set the pass_filenames to true. When there are 11 files to modify in the git staging area, the hook is called three times with different filename arguments each time. I would like the hook to be called only once with all filenames.

This is my hook:

repos:
  - repo: local
    hooks:
      - id: ruff-format
        name: ruff-format
        entry: "bin/ruff-format"
        language: script
        pass_filenames: true
        files: "src/python/|test/python/"
        types: [python]

Can this be accomplished? Am I doing something wrong? Thank you.

Answer 1

you can never guarantee that they will happen in exactly one call because commands have an operating system dependent length limit

you can hint at pre-commit that your particular tool is not parallel safe via require_serial: true. this has the side effect of batching as much as possible but again cannot guarantee a single call

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disclaimer: I wrote pre-commit