tools/ruff.sh: Allow restricting checking to specific subtrees

[PeterNerlich]

Short description

With #3333 just merged, ruff became our main linting tool. However if you're like me and have a lot of messy files and experiments lying around your working directory, you might want to restrict ruff to only look at a few subtrees in your project. While the performance improvement barely matters because ruff is already so fast, you will appreciate having irrelevant files untouched and ruff only printing messages about files you care about.

Proposed changes

• Parse arguments to tools/ruff.sh and save them to PATHS
• Set PATHS to BASE_DIR if none are supplied
• Run both ruff check --fix and ruff format only for PATHS

Side effects

• None, this change is fully backwards compatible to the previous intended usage. But if you relied on the tool ignoring any arguments at the end, it will now either complain that the file doesn't exist or lint those files.

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Pull Request Review Guidelines

[charludo]

Thank you, I think this is a great idea! I have an extension of this in mind though, which also brings some simplification. It looks like ruff check and ruff format --check do the exact same thing as ruff check . and ruff format --check ., meaning we could just default to not providing a path at all, and simply pass all arguments given to ./tools/ruff.sh to both of those calls, the same way we're already doing for the pre-commit hooks.

Cons:

• no checking if passed paths actually exist. Do you have a specific usecase for this in mind? Otherwise I think ruff's own error message is already pretty succinct:

  error: Failed to format help-i-dont-exist: No such file or directory (os error 2)
  

Pros:

• much simpler logic. Just need to change

  ruff check --fix . || true
  ruff format .

  to

  ruff check --fix "$@" || true
  ruff format "$@"

• more importantly though, that makes it trivial to pass additional flags to ruff. For example, I have really been wanting a way to append --unsafe-fixes a lot lately 😁
  (OK, to be fair this will throw some errors because format and check don't share a lot of flags, but it would certainly still be servicable)

[PeterNerlich]

we could just default to not providing a path at all, and simply pass all arguments given to ./tools/ruff.sh to both of those calls

Yeah I'm also fine with that, I just copied it from tools/test.sh and removed everything that was tests-specific… as in, everything but the overarching structure :D

(OK, to be fair this will throw some errors because format and check don't share a lot of flags, but it would certainly still be servicable)

Yes I tried to look it up but didn't immediately find a comprehensive list of available options for both commands, so I just left it at the paths. I was wanted to keep the structure for this actually, so we could add flags and what to do with it later (to add it to one or the other ruff command, or some custom logic)

[charludo]

we could just default to not providing a path at all, and simply pass all arguments given to ./tools/ruff.sh to both of those calls

Yeah I'm also fine with that, I just copied it from tools/test.sh and removed everything that was tests-specific… as in, everything but the overarching structure :D

(OK, to be fair this will throw some errors because format and check don't share a lot of flags, but it would certainly still be servicable)

Yes I tried to look it up but didn't immediately find a comprehensive list of available options for both commands, so I just left it at the paths. I was wanted to keep the structure for this actually, so we could add flags and what to do with it later (to add it to one or the other ruff command, or some custom logic)

Hm. It would probably be easier to split the tool into two (ruff_format.sh, ruff_check.sh) and call both from ruff.sh than to mainting a list of what-arg-goes-where for every conceivable usecase.

The custom logic right now is not doing anything except remove non-existing paths, and print an error similar to what ruff would do anyways, right? IMO that is not enough benefit to justify 25 lines of shellscript 🙈