(🐞) `staticmethod` special-casing causes error to not be reported
Open
Nobody has claimed this yet.
bug
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
- PR merge metrics
- PR metrics pending
Description
If we copy the implementation of staticmethod from typeshed, mypy correctly reports the error here.
So it seems that mypys dedicated special-casing of staticmethod is causing this issue to be incorrectly not reported.
from collections.abc import Callable
from typing import Generic, ParamSpec, TypeVar, overload
P = ParamSpec("P")
T = TypeVar("T")
R_co = TypeVar("R_co", covariant=True)
def contextmanager(fn: Callable[P, R_co]) -> Callable[P, R_co]:
def func(*args: P.args, **kwargs: P.kwargs) -> R_co:
return fn(*args, **kwargs)
return func
class staticmethod_copy(Generic[P, R_co]):
@property
def __func__(self) -> Callable[P, R_co]: ...
@property
def __isabstractmethod__(self) -> bool: ...
def __init__(self, __f: Callable[P, R_co]) -> None: ...
@overload
def __get__(self, __instance: None, __owner: type) -> Callable[P, R_co]: ...
@overload
def __get__(self, __instance: T, __owner: type[T] | None = None) -> Callable[P, R_co]: ...
__name__: str
__qualname__: str
@property
def __wrapped__(self) -> Callable[P, R_co]: ...
def __call__(self, *args: P.args, **kwargs: P.kwargs) -> R_co: ...
# Just the relevant part of staticmethod definition that is needed
#class staticmethod(Generic[P, R_co]):
# def __init__(self, __f: Callable[P, R_co]) -> None: ...
# def __call__(self, *args: P.args, **kwargs: P.kwargs) -> R_co: ...
class Foo:
@contextmanager
@staticmethod_copy
def copy() -> None: ...
@contextmanager
@staticmethod
def native() -> None: ...
Foo().copy() # ✅ error: Attribute function "copy" with type "Callable[[], None]" does not accept self argument [misc]
Foo().native() # ❌no error
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the provided example and compare mypy's dedicated staticmethod special-casing with the copied typeshed implementation. Trace how the decorators and descriptor types are analyzed; done means mypy reports the missing-self error for Foo().native() as it does for Foo().copy().
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100