Hook takes minutes and may fail without a valid reason on medium/big codebases

[danielelotito]

Describe the bug
The add-headers pre-commit hook from hashicorp/copywrite is exhibiting significant performance issues and occasional failures. On my development machine, the hook takes between 1.5 and 3.2 minutes to complete (on a rather big repo, https://github.com/IBM/ado), which slows down the commit process considerably.

Additionally, the hook sometimes fails when it should have passed.

To Reproduce
Steps to (try to) reproduce the behavior:

Clone the repository where the issue is observed: git clone https://github.com/IBM/ado

Follow the project's development setup instructions: Project Setup Guide

Stage some files and attempt to commit the changes: git commit

Expected behavior
I expect the add-headers hook to run quickly (ideally in a few seconds) and to only modify files when copyright headers are genuinely missing or incorrect. It should not fail a commit when the headers are already compliant.

Screenshots / Log Files
Here is an example of the output when the hook fails without a legitimate reason:

git -c user.useConfigOnly=true commit --quiet --allow-empty-message --file -
Detect secrets...........................................................Passed
ruff (legacy alias)..................................(no files to check)Skipped
black-jupyter........................................(no files to check)Skipped
codespell................................................................Passed
uv-lock..............................................(no files to check)Skipped
uv-export............................................(no files to check)Skipped
Add copyright headers....................................................Failed
- hook id: add-headers
- files were modified by this hook
Using license identifier: MIT
Using copyright holder: IBM Corporation
[1mExempting the following search patterns:\[0m
\[36m.cra/\*\*\[0m
\[36m.eggs/\*\*\[0m
\[36m.git/\*\*\[0m
\[36m.github/\*\*\[0m
\[36m.idea/\*\*\[0m
\[36m.pre-commit-config.yaml\[0m
\[36m.tox/\*\*\[0m
\[36m.venv/\*\*\[0m
\[36m.vscode/\*\*\[0m
\[36m\*\*build/lib/\*\*\[0m
\[36mdist/\*\*\[0m
\[36mtoxenv/\*\*\[0m
\[1mUpdating existing copyright headers:\[0m
\[1mAdding missing copyright headers:\[0m
markdownlint-cli2........................................................Passed
yamlfmt..............................................(no files to check)Skipped
tombi-format.........................................(no files to check)Skipped

env

OS: macOS

Python Version: 3.12 (failed with 3.10.7 as well)

copywrite version: v0.25.1

  - repo: https://github.com/hashicorp/copywrite
    rev: v0.25.1
    hooks:
      - id: add-headers