(🎁) Special case `NoReturn`, `Never`, `Self` and `TypeAlias` to not be subscriptable
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feature
priority-2-low
- Dominant language
- Python
- Stars
- 20.6k
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Description
from typing import NoReturn, Never, Self and TypeAlias
NoReturn[int]
Never[int]
Self[int]
TypeAlias[int]
All of these usages are a 'no error moment'.
These methods exist at runtime, but are noops that just raise TypeErrors (:trollface:)
I would expect warnings on any of these usaages especially Self as I could imagine every single person trying to use it with type parameters(it doesn't support type parameters 😢).
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the four examples involving NoReturn, Never, Self, and TypeAlias and inspect the type-checking path for subscripting them. Done means each invalid subscript produces a warning or error, especially Self, with coverage for the reported usages.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100