Ruff target-version can be automatically inferred if requires-python is set

[burgholzer]

According to https://beta.ruff.rs/docs/settings/#target-version, the target-version property used for ruff can be inferred from the project.requires-python field, if it is present.
Repo-review currently requires the target-version to be set in

cookie/src/sp_repo_review/checks/ruff.py

Lines 35 to 50 in 884ef32

	class RF002(Ruff):
	"Target version must be set"
	requires = {"RF001"}
	@staticmethod
	def check(pyproject: dict[str, Any]) -> bool:
	"""
	Must select a minimum version to target. Affects pyupgrade,
	isort, and others.
	"""
	match pyproject:
	case {"tool": {"ruff": {"target-version": str()}}}:
	return True
	case _:
	return False

Based on the above, this check could be relaxed a little. Maybe to something like:

class RF002(Ruff):
    "Target version must be set"
    requires = {"RF001"}

    @staticmethod
    def check(pyproject: dict[str, Any]) -> bool:
        """
        Must select a minimum version to target. Affects pyupgrade,
        isort, and others. Can be inferred from project.requires-python.
        """

        match pyproject:
            case {"tool": {"ruff": {"target-version": str()}}}:
                return True
            case {"project": {"requires-python": str()}}:
                return True
            case _:
                return False

Or even something where it is suggested to not specify tool.ruff.target-version whenever project.requires-python is specified.

[henryiii]

This sounds great. I’d go with allowing either for now, as you have above, and later we could make having both disallowed.

[henryiii]

(I suspect this might be somewhat new. Also wondering how it handles more complex version boudaries)

[burgholzer]

This sounds great. I’d go with allowing either for now, as you have above, and later we could make having both disallowed.

Do you want me to submit a corresponding PR?

(I suspect this might be somewhat new. Also wondering how it handles more complex version boudaries)

The feature was requested in astral-sh/ruff#2039 and implemented in astral-sh/ruff#3470 on March 13, which went into ruff v0.0.255 (https://github.com/astral-sh/ruff/releases/tag/v0.0.255). astral-sh/ruff#2039 has some details on the handling of version ranges (mostly refers to how black handles this as of version 23.1.0).

[henryiii]

Sure, please do.

[henryiii]

(FYI, this check was added in repo-review 0.5, https://github.com/scientific-python/repo-review/releases/tag/v0.5.0 - in February, which explains why it didn't have this :) )