False positive when using generic protocol in overload signature #5285
Description
From pandas-dev/pandas-stubs#729:
from typing import overload, Protocol, TypeVar, Any
AnyStr_contra = TypeVar("AnyStr_contra", str, bytes, contravariant=True)
class Buffer(Protocol):
def __bytes__(self) -> bytes:
...
class BytesIO:
def write(self, __b: Buffer) -> None:
pass
class WriteBuffer(Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
...
class NDFrame:
@overload
def to_csv(self, path_or_buf: WriteBuffer[bytes]) -> None:
...
@overload
def to_csv(self, path_or_buf: None = ...) -> str:
...
def to_csv(self, path_or_buf: Any = None) -> Any:
...
def test_types_to_csv() -> None:
df = NDFrame()
df.to_csv(BytesIO())