python / python/mypy

Disallow `type[NoReturn]`

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bug priority-2-low topic-pep-484
Dominant language
Python
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Description

from typing import NoReturn

# Incompatible types in assignment (expression has type "object", variable has type "Type[NoReturn]")  [assignment]
foo: type[NoReturn] = NoReturn 

https://mypy-play.net/?mypy=latest&python=3.10&gist=ae2c337cc5fdfe2a3022aaae54903012

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Research direction

Reproduce the shown assignment using the linked mypy-play example and confirm the current diagnostic. Locate the type-checking path that accepts type[NoReturn], add coverage for this case, and verify that mypy rejects it without changing valid NoReturn behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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