[FYI] mypy_primer

[hauntsaninja]

With apologies to black_primer, I jotted down a script that lets us run mypy over a large amount of open source Python code. Hopefully this helps democratise the process of identifying issues and regressions and evaluating risky changes.

This has informed:
python/typeshed#4579
python/typeshed#4574
python/typeshed#4582
python/typeshed#4583
And you can see it in action at:
#9275
#9290 (comment)

More details at: https://github.com/hauntsaninja/mypy_primer

Feel free to close or otherwise discuss!

[TH3CHARLie]

Very interesting(and of course powerful) utility!

[obi1kenobi]

This seems pretty cool, nicely done!

Does it support mypy settings other than the defaults? Asking because in #9493 I ran into an issue where seemingly relaxing mypy's settings from their default values caused a crash when analyzing xarray as a dependency of another project, and I noticed that one of the issues you found and helped fix was discovered by analyzing xarray.

[hauntsaninja]

Not quite, it's meant to try to invoke mypy the way the projects are invoking mypy. So each project has a hardcoded mypy command that I stole (usually from their CI) / it picks up the projects' mypy configuration files.
I do agree that using mypy_primer is a good approach to explore / test flags and it should be fairly easy to change the script to do this sort of thing.

PS: Thanks for sharing and writing typing_copilot, seems useful! I've seen a number of projects setting ignore_errors = True in their config files as a way of ratcheting (e.g scipy). Incorporating stricter settings for subpackages like that into typing_copilot could be a interesting (but potentially complex) addition.

[hauntsaninja]

Closing, since mypy_primer is now in mypy CI.