false positive errors when calling operator override that returns `Never` from another function that returns `Never`
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bug
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
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Description
from typing import Never
class Foo:
def __mul__(self, value: float, /) -> Never:
raise Exception("multiplication is banned")
def __rmul__(self, value: float, /) -> Never: # error: Implicit return in function which does not return [misc]
self * value
def __rmul_attempt_2__(self, value: float, /) -> Never:
return self * value # error: Return statement in function which does not return [misc]
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
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- Open a pull request that references the issue number.
Research direction
Reproduce the diagnostics in the linked mypy playground using the two Never-returning operator examples. Then locate the relevant return and Never checking path and add a regression test showing that both calls are accepted; done when the false-positive errors disappear without weakening the intended Never checks.
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
- Clearly specified
- Newbie friendliness
- 45/100