Not easy to test the diff_cover locally
I don't want to "push" the need for a "tox.ini" file, but I was surprised to discover that this package does not use any python test orchestrator. Tox is the most popular but other alternatives like nox are also acceptable.
Why? I discovered that diff_cover was not working well with py313 and didn't even have a github pipeline testing it. While trying to make a PR to enable it I found that there is no way to test it locally without involving a lot of manual venv setups, which clearly would make local vs CI testing diverge even more.
In fact while raising the PR, I discovered another problem which discourage contributing: CI does not run without approval. Anyway, this once is easy to fix in repo settings.
Its not clear to me what manual steps are required. You should be able to just follow the same steps as the github workflow. Install python, install poetry, run poetry install, run verify.sh
I wrote this out here: https://github.com/Bachmann1234/diff_cover/issues/479
You can change the python version (hard coded to python:3.12) to anything you want and run either ./verify.sh as @Bachmann1234 mentioned, or pytest -n auto -- which is what i do 99% of the time.
With this, you can simulate any python version you want, and ensure nothing breaks.. completely isolated!
I do want to mention, I'm on MacOS, and since my docker is a virtual machine, not all the permissions will work if you're in a real *nix box