Introduce ruff

[neob91-close]

Ruff is a linter boasting extreme speed and near-parity with the flake8 ruleset.

While speed is important, I think its greatest benefit is the ability to automatically fix issues.
Not sure whether it could replace flake8, but if it doesn't conflict with it or black, it would be a great addition IMO.

[neob91-close]

CC @nsaje @tsx

[nsaje]

I would love a flake8 autofix functionality, I am a bit concerned with the maturity of ruff though - seems like it's quite new and under very active development.

How about considering https://github.com/PyCQA/autoflake ?

[AlecRosenbaum]

TIL about ruff.

I'd be happy with anything that automatically fixes unused imports, though it seems like ruff is pretty widely used by rather mature projects. If it really is as fast as it claims, both its speed and ability to auto fix feels like a game changer.

[vtclose]

It does look very interesting. I'm gonna test it out.

[vtclose]

It does look very good indeed. It covers more or less everything we need from flake8 and it's instant. 0.5s without cache, 0.1s with cache on our main codebase. Ruff even covers like 90% of our isort, only being incompatible with a couple configuration options. I'm more than willing to give up the remainder for autofix + instant linting.

If we replace both isort and flake8 with ruff, the only other tools in our setup are black and mypy, and neither of those need the "--changed" functionality. And with just 3 tools, maintaining a separate umbrella package for linting tools is pretty much unnecessary, so we can get rid of lintlizard altogether.

Thoughts?

[neob91-close]

Well, if we replaced flake8 and isort with ruff, then perhaps lintlizard might seem like overkill a little bit, but I don't think we should get rid of it just yet:

• it is still nice to have a single command to run everything, with a summary of whether any of the tools failed (and which). Also, when we introduce Conceal output of tools that succeeded #149 at some point, it will become that much more convenient.
• We were planning to move linter configurations to lintlizard so we could keep a consistent setup across our projects. I think lintlizard would still be a good place for that.