TypeVar with constraints cannot specify overloads
Open
Nobody has claimed this yet.
bug
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
- PR merge metrics
- PR metrics pending
Description
TypeVar with constraints (e.g. TypeVar('NumberT', int, float)) cannot be used to specify an overload: that is, it can be used, but seems to go unchecked.
To Reproduce
https://mypy-play.net/?mypy=latest&python=3.10&gist=30f7918d00fbe9c4a86bfacea2d20da3
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 with the linked mypy-play reproducer and inspect the type-checking path for constrained TypeVar usage in overloads. Determine why the invalid overload is accepted, then add a regression test covering the reproducer and verify that the overload is rejected or checked as intended.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100