add pre-commit with ruff

[ShaiahWren]

[AAP-38768]

Description

This work ensures that each time a developer attempts a commit,

• a pre-commit hook with uv+ruff for linting and formatting is run
• in order to arrest the commit if linting/formatting discrepancies are detected and provide useful feedback in the output log.

Set-up

• in /metrics-utility root dir, run uv sync & uv run ruff / uvx ruff to manage the uv virtual env and add the dependencies.
• Ensure deps have been installed with checks such as ruff --version; pytest --version; django-admin --version; pre-commit --version;
• If deps are missing try uv sync again

Testing

• create a small test file, such as "test.py", and type any incorrectly formatted or linted python.
• add the file and attempt to commit the change

Expected Results

Commit should not complete; it will direct you some output that explains what the pre-commit-with-uv+ruff found.

[dhaustein]

I failed to make it work on my end. I can do $ pre-commit run manually and that will pickup the errors I made in my test.py file.

$ pre-commit run
ruff.....................................................................Failed
- hook id: ruff
- exit code: 1

But when I do git add test.py and git commit -m "commit bad file" it will happily let me.

$ vim test.py  # added the example from here https://realpython.com/ruff-python/#checking-for-errors

$ git add .

$ git commit -m 'test: test pre-commit hook'
[pr/42 59ac220] test: test pre-commit hook
 1 file changed, 18 insertions(+)
 create mode 100644 test.py

$ git status
On branch pr/42
nothing to commit, working tree clean

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🎆 EDIT: I had to re-run $ pre-commit install and then everything started working as expected. I suggest adding this as an extra install step to the Set-up steps.

[himdel]

The changes look good 👍 ,

just, did you run uv sync after the last change? Looks like when I git pr 42; uv sync, it updates the lockfile, adding pre-commit, so maybe it wasn't up to date?

(Also, it warns about a missing requires-python, adding a requires-python = ">=3.12" to the project section in pyproject.toml, and a doing an echo 3.12 > .python-version seems to fix this .. unless we're keeping the version out deliberately?)

[himdel]

In this PR description's Set-up section:

in /metrics-utility root dir, create and activate your venv with python -m venv venv; source venv/bin/activate
install the deps using pip install

This bit seems surprising? uv manages virtual environmeents & dependencies for you, so I'd expect these to be something like "run uv sync" & uv run ruff / uvx ruff etc.? Or uv venv ; source .venv/bin/activate instead of directly talking to virtualenv & pip?

[himdel]

LGTM 👍 , no warnings, no diff after sync, works for me :)