Wrong overload resolution with alias to Any
Bug Report
Overload resolution appears to pick the first matching overload if the argument type is an alias to Any. It should consider all overloads. This works correctly when using Any directly (without an alias). This came up in https://github.com/python/typeshed/issues/10405.
To Reproduce
from typing import Any, Union, overload
@overload
def my_origin(x: type) -> type: ...
@overload
def my_origin(x: Any) -> Any: ...
def my_origin(x: Any) -> Any:
return x
def call_any(spec: Any) -> bool:
return my_origin(spec) is Union
TypeSpec = Any
def call_alias(spec: TypeSpec) -> bool:
return my_origin(spec) is Union
https://mypy-play.net/?mypy=latest&python=3.11&flags=strict&gist=26e08b7414caad553cd0e9549928da11
Expected Behavior
Both call_any and call_alias should type check without errors, since they are the same thing.
Actual Behavior
call_alias produces an error in strict mode:
proj/overload.py:18: error: Non-overlapping identity check (left operand type: "type", right operand type: "<typing special form>") [comparison-overlap]
Your Environment
- Mypy version used: 1.4.1
- Mypy command-line flags: --strict
- Python version used: 3.10.6
Adding reveal_type calls to the example confirms that mypy is picking a different overload with the alias-to-Any version: https://mypy-play.net/?mypy=latest&python=3.11&flags=strict&gist=8b3429d9daae0e46ebc64d5aae592513