Wrapped overloaded function drops all but the first overload #15737
Description
Bug Report
When wrapping an overloaded function and using ParamSpec to preserve the call signature, only the first overload is preserved on the resulting function.
To Reproduce
See:
- https://gist.github.com/mypy-play/96895b9df7aa87c9e9f6cc59203d0751
- https://mypy-play.net/?mypy=latest&python=3.11&gist=96895b9df7aa87c9e9f6cc59203d0751
from typing import Callable, overload, TypeVar
from typing_extensions import ParamSpec
P = ParamSpec("P")
T = TypeVar("T")
def transform(func: Callable[P, list[T]]) -> Callable[P, T]:
def wrapped(*args: P.args, **kwargs: P.kwargs) -> T:
return func(*args, **kwargs)[0]
return wrapped
@overload
def foo(x: int) -> list[float]:
pass
@overload
def foo(x: str) -> list[str]:
pass
def foo(x: int | str) -> list[float] | list[str]:
if isinstance(x, int):
return [1 / x]
return [x[::-1]]
bar = transform(foo)
assert bar(2) == 0.5
assert bar("abc") == "cba"
reveal_type(foo)
reveal_type(bar)Expected Behavior
I would expect the overloads to be preserved on the decorated function, e.g.
main.py:31: note: Revealed type is "Overload(def (x: builtins.int) -> builtins.list[builtins.float], def (x: builtins.str) -> builtins.list[builtins.str])"
main.py:32: note: Revealed type is Overload(def (x: builtins.int) -> builtins.float, def (x: builtins.str) -> builtins.str)"
Actual Behavior
main.py:29: error: Argument 1 has incompatible type "str"; expected "int" [arg-type]
main.py:31: note: Revealed type is "Overload(def (x: builtins.int) -> builtins.list[builtins.float], def (x: builtins.str) -> builtins.list[builtins.str])"
main.py:32: note: Revealed type is "def (x: builtins.int) -> builtins.float"
Your Environment
- Mypy version used: 1.4.1
- Python version used: 3.10.10