Drop .choices from model field choices

[UnknownPlatypus]

Fixes #336

This might break if someone designed a custom class with a choices property which is not a django enumeration class but I don't think this is really a use case ?
The documentation links are not yet valid, I think we have to play the waiting game when this MR seems ready for you.

Cheers

[adamchainz]

Hmmm. “I don't think this is really a use case?” is kinda shaky evidence. I agree it seems rather unlikely but maybe some people went out of their way to do so, perhaps copy-pasting in the old versions of the Choices classes as a backport, then never upgrading.

it’s probably okay, but this is also a very tiny improvement, especially since the choices attribute is being retained without deprecation.

hmm, I’m kinda split on this one.

[UnknownPlatypus]

perhaps copy-pasting in the old versions of the Choices classes as a backport, then never upgrading.

Indeed this is more likely. Maybe it's time to have some sort of configuration added to select rules ? I'm thinking of 2 possible ways of doing it:

• Adding a way to select/exclude some fixers when running django-upgrade. This would also cover Add option to select specific fixer to run #333. We could also disable some maybe unsafe rules (like this one) by default and require user opt-in.
• Adding some sort of applicability flag (--unsafe/--safe), we could then flag individual fixers as safe or not and only apply safe fixers by default. One could enable everything using the --unsafe flag. (I'm not sure I really like this option, I feel like It lacks some granularity compared to the other option)

it’s probably okay, but this is also a very tiny improvement, especially since the choices attribute is being retained without deprecation.

I agree this is a tiny improvement but since it has been added to django core, I think it's good to push this feature (and I do think it's more user-friendly from an API perspective.

[adamchainz]

Thanks for rebasing after I added the 5.0 support.

Returning to the conversation, I think this would actually be pretty safe. Looking again, I think you were probably right that the chances are slim that anyone actually has a custom class with .choices. Let’s go ahead as is and fix if anyone reports issues.

I have some comments about expanding the scope, if you wouldn't mind.

[UnknownPlatypus]

Thanks the thorough review, will look into it later this week 👌

[adamchainz]

Great work, gonna do final edits and merge

[adamchainz]

Good work. I think I'll actually split looks_like_models_file and this change into a separate PR.