Closed
Description
Bug Report
Mypy does not match dict[int, int] with Mapping[Hashable, Any] when it is in Union[Mapping[Hashable, Any], Hashable] but it matches when Mapping[Hashable, Any] is by itself.
To Reproduce
Example from @Dr-Irv:
from typing import Mapping, Hashable, Any, Union
def myfun(m: Mapping[Hashable, Any]):
...
def myfun2(m: Union[Mapping[Hashable, Any], Hashable]):
...
myfun({1: 1}) # passes
myfun2({1: 1}) # errorsExpected Behavior
No error.
Actual Behavior
error: Argument 1 to "myfun2" has incompatible type "Dict[int, int]"; expected "Union[Mapping[Hashable, Any], Hashable]"
note: Following member(s) of "Dict[int, int]" have conflicts:
note: __hash__: expected "Callable[[], int]", got "None"
No error with pyright.
Your Environment
- Mypy version used: 0.942