Open
Description
Bug Report
mypy failed to return the correct overloaded func type when decorate func accepts more than one parameter.
To Reproduce
from functools import wraps
from typing import overload, Any, TypeVar, Callable, Type
from typing_extensions import ParamSpec, reveal_type
@overload
def foo(a: str, /) -> str:
pass
@overload
def foo(a: int, /) -> int:
pass
def foo(a: Any) -> Any:
return a
P = ParamSpec("P")
T = TypeVar("T")
R = TypeVar("R")
def forbid_return_type(
func: Callable[P, T],
tp: Type[Any],
/,
) -> Callable[P, T]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> T:
result = func(*args, **kwargs)
if isinstance(result, tp):
raise TypeError(f"Return type {tp} is forbidden")
return result
return wrapper
foo_as_int = forbid_return_type(foo, str)
reveal_type(foo_as_int(1))
reveal_type(foo_as_int("1"))Expected Behavior
note: Revealed type is "builtins.int"
note: Revealed type is "builtins.str"Actual Behavior
note: Revealed type is "builtins.str"
error: Argument 1 has incompatible type "int"; expected "str" [arg-type]
note: Revealed type is "builtins.str"Your Environment
- Mypy version used: mypy 1.14.0+dev
- Mypy command-line flags: -
- Mypy configuration options from
mypy.ini(and other config files): - - Python version used: 3.8.19
Both codes bellow work as expected:
from functools import wraps
from typing import overload, Any, TypeVar, Callable
from typing_extensions import ParamSpec, reveal_type
@overload
def foo(a: str, /) -> str:
pass
@overload
def foo(a: int, /) -> int:
pass
def foo(a: Any) -> Any:
return a
P = ParamSpec("P")
T = TypeVar("T")
R = TypeVar("R")
def forbid_return_type(
func: Callable[P, T],
) -> Callable[P, T]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> T:
result = func(*args, **kwargs)
return result
return wrapper
foo_as_int = forbid_return_type(foo)
reveal_type(foo_as_int(1))
reveal_type(foo_as_int("1"))from functools import wraps
from typing import Any, TypeVar, Callable, Type, Union
from typing_extensions import ParamSpec, reveal_type
def foo(a: Union[int, str]) -> Union[int, str]:
return a
P = ParamSpec("P")
T = TypeVar("T")
R = TypeVar("R")
def forbid_return_type(
func: Callable[P, T],
tp: Type[Any],
/,
) -> Callable[P, T]:
@wraps(func)
def wrapper(*args: P.args, **kwargs: P.kwargs) -> T:
result = func(*args, **kwargs)
if isinstance(result, tp):
raise TypeError(f"Return type {tp} is forbidden")
return result
return wrapper
foo_as_int = forbid_return_type(foo, str)
reveal_type(foo_as_int(1))
reveal_type(foo_as_int("1"))So it's not working only when the function accepts an overloaded function and another argument.
I checked with pyright and it correctly handles code.
/Users/yuriikarabas/projects/mypy/temp.py:45:13 - information: Type of "foo_as_int(1)" is "int"
/Users/yuriikarabas/projects/mypy/temp.py:46:13 - information: Type of "foo_as_int("1")" is "str"
0 errors, 0 warnings, 2 informations