TC does not detect imports used only for type annotations

[devon-research]

Summary

It seems that some of the TC rules are not working correctly. For example, if I have this file:

from typing import NamedTuple

t: NamedTuple | None = None

and I run

ruff check --isolated --select=TC

then I get that all checks pass.

My understanding is that this should yield a TC003 error. Am I misunderstanding the intended behavior?

Version

0.9.4

[MichaReiser]

Types imported from the typing module are excempt from moving into TYPE_CHECKING by default because you still have to import the typing module to get the TYPE_CHECKING variable at runtime. So the benefit of moving types imported from typing is marginal. See Charlie's response here #9197 (comment)

However, you can remove typing from the excempt-module list and ruff will start enforcing moving typing imports in the TYPE_CHECKING block

[lint]
select = [ "TC" ]

[lint.flake8-type-checking]
exempt-modules = []

See https://play.ruff.rs/9ccf9a06-534c-441a-8101-02056076b8a6

[devon-research]

Ah, I see. Thanks!

I additionally had this confusion come up outside the typing module, but I realize now from the issue you linked that the behavior I was seeing is explained by the strict = false default.