Use cross-platform regexes for some State.looks_like* functions

[CLWilliam]

Fixes #283

• looks_like_migrations_file and looks_like_command_file are converted to regex based filename checks.
• Tests for looks_like_migrations_file added
• git example added for powershell to apply django-upgrade on multiple files

[adamchainz]

Thanks this is looking good.

Please add a changelog note in HISTORY.rst following the existing style (whenever you make an open source contribution.

[adamchainz]

please sort the regexes alphabetically, the same order that the methods are in

The commands method did deliberately check the current file lives within commands, which the regex currently doesn’t. I think we could modify it like so to capture this:

commands_re = re.compile(r"(^|[\\/])management[\\/]commands[\\/][^\\/]+$")

Since you’re adjusting commands_re, please ensure it is tested with both \ and /

[CLWilliam]

This one fails on myapp/subapp/management/commands/test/subcommand.py as it has a subfolder and thus an additional path separator. expanding it to

(^|[\\/])management[\\/]commands[\\/][^\\/]+[\\/]*[^\\/]*$

captures one subfolder. Pushing it further to 0 or more subfolders brings:

(^|[\\/])(management[\\/]commands[\\/])([^\\/]+[\\/]+)*([^\\/]+)$

--> regexr.com/71kmn

Commands tests are also updated for windows paths.

[adamchainz]

Yeah, that was a deliberate suggestion - subdirectories won't be picked up as management commands by Django, so we can ignore certain fixers there.

[adamchainz]

Ah actually my bad, I didn't realize subcommand was in the existing tests. We can keep support for subcommand. Reverting to your original easier regex since the 0+ folders search is verbose and doesn’t help much.

[adamchainz]

Thank you!

[CLWilliam]

Thanks for the guidance! It was a nice way to see the full issue to merge cycle!