Switch to pre-commit for Git hooks

[Calinou]

Marking as a draft since this needs to be tested on Windows and macOS.

This replaces our custom Git hook solution for pre-commit, a framework for pre-commit hooks written in Python.

It should have better Windows support than our existing implementation, on top of being able to handle CI situations and partial commits nicely. By default, it will only run on files modified since the last commit.

The minimum required version is Python 3.6.

See https://pre-commit.com/ for more information.

Note: Java and Objective-C++ files won't be formatted by this hook until pocc/pre-commit-hooks#25 is merged and a release of the clang-format pre-commit hooks is tagged.

This closes #46224.

[bruvzg]

On macOS everything except makerst hook is working (fixed by changing command to python3, on macOS python points to 2.7.16).

[bruvzg]

Suggested change

	entry: python doc/tools/makerst.py doc/classes modules --dry-run
	entry: python3 doc/tools/makerst.py doc/classes modules --dry-run

[akien-mga]

Might need testing on Windows as typically the installed binary there is python.exe for Python 3.
And apparently @BastiaanOlij has a setup where it's py.exe 🙀

[bruvzg]

Indeed, Windows seems to use python.exe, at least when it's installed from www.python.org. And probably won't run the script directly if python is removed from the command (which is also a valid option on macOS). I'll check whether it works on Windows at all a bit later.

[bruvzg]

I'll check whether it works on Windows at all a bit later.

Seems to work fine on Windows.

probably won't run the script directly if python is removed

Windows shell is capable of running python scripts directly, but pre-commit is not.

[BastiaanOlij]

Might need testing on Windows as typically the installed binary there is python.exe for Python 3.
And apparently @BastiaanOlij has a setup where it's py.exe 🙀

Yeah but the thing is this stupid STUB thing that Windows does so if you try and run python, instead of it running your installed python, it will run this little program that redirects you to MSVC and tells it to install its version of Python. Like WTF..

py.exe worked because that didn't have a stub.

Can't remember the suggestion but someone told me how to turn that off and now the python executable in my python install works

[yedpodtrzitko]

pre-commit has a config option default_language_version. Setting it to python3 is enough to use Python 3 even with python executable name

minimal reproducible example:

default_language_version:
  python: python3

repos:
-   repo: local
    hooks:
    -   id: check-version
        name: check python version
        language: python
        entry: python --version
        files: ".*"

$ pre-commit run --verbose
>>> Python 3.10.6

output with python: python2:

>>> Python 2.7.17

[BastiaanOlij]

Worked fine for me in windows. Fixed up a bunch of format things I mangled. Only test it failed was adding a newline at the end of the file.

[aaronfranke]

I think it would be a good idea if the pre-commit hooks were added without removing the Bash formatting scripts. This would allow the pre-commit hooks to be more broadly tested with little risk.

Additionally, if the CI was using the pre-commit hooks, what we could do is revert #46050 such that the Bash formatting scripts are reserved for occasional manual use and would do more than the typical scripts (like what we currently do with clang-tidy).

[aaronfranke]

What's the reason that this is still a draft? Also, my comment above still applies, we don't need to remove the Bash scripts in order to add the pre-commit Git hooks.

[Calinou]

What's the reason that this is still a draft? Also, my comment above still applies, we don't need to remove the Bash scripts in order to add the pre-commit Git hooks.

Hooks have received many updates since I opened this PR, so this needs to be salvaged. I don't have time to do it currently.

[Calinou]

• Superseded by Use pre-commit for pre-commit hooks and CI #87003.