MAINT: Adding ruff unsafe-fixes

[prady0t]

Towards #228

[ev-br]

I'd like to understand why these are unsfafe-fixes. The changes seem to be of two groups:

• typing -> Array replaced by -> Self (ok whatever)
  This should be perfectly safe at runtime
• nested ifs collapsed with either and or isinstance(object, tuple_of_types)
  The former form shortcuts fine, the latter... probably shortcuts too, not sure.
  Plus benign refactors of if-else into a dict.get etc.

And if it's labeled as unsafe, it means I don't see something, so what is it I'm not seeing: Which of these is unsafe and how?

[prady0t]

I'd like to understand why these are unsfafe-fixes.

See: https://docs.astral.sh/ruff/linter/#fix-safety

I think for the first part: the conditional import is something that I added manually; originally Ruff just imported Self from typing. But for older versions, it's only available in typing_extensions. And the CI did fail on that.

For the second part, I'm not sure about it either.

[ev-br]

Thanks for the link. My question is still why these fixes are "unsafe" in the meaning of that link: what are the changes to the runtime behaviour.

[prady0t]

After a bit more digging through the docs:

• PYI034: https://docs.astral.sh/ruff/rules/non-self-return-type/

This rule's fix is marked as unsafe as it changes the meaning of your type annotations.

• SIM102: https://docs.astral.sh/ruff/rules/collapsible-if/

When preview is enabled, the fix for this rule is considered as safe. When preview is not enabled, the fix is always considered unsafe.

[ev-br]

Thanks for digging through their docs! It all makes sense now.
For SIM102 could you please keep the changes but disable the rule globally? And then merge.
Reason: starting from a nested if, it will first collapse it into one, then activate the line length rule and break the line with brackets. The net effect is even funnier indentation, plus back-and-forth for a human author.

[prady0t]

The net effect is even funnier indentation, plus back-and-forth for a human author.

Totally agreed!

[prady0t]

Also added some comments in ruff.toml

[ev-br]

Thank you @prady0t , merged.