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🐛 Methods converted to staticmethods using a decorator not treated as staticmethods #13434
Description
Bug Report
The @staticmethod decorator only appears to work with MyPy when used as a decorator.
For example, the following code works:
class MyClass:
@staticmethod
def my_method():
...However, the following code does not work:
from typing import Callable
def make_staticmethod(func: Callable, /) -> staticmethod:
return staticmethod(func)
class MyClass:
@make_staticmethod
def my_method():
...The above code produces the following error:
error: Method must have at least one argumentTo Reproduce
- Run MyPy against the non-working example shown above
Expected Behavior
MyPy sees that the decorator returns a staticmethod and proceeds to treat MyClass.my_method as a staticmethod
Actual Behavior
MyPy produces the following error:
error: Method must have at least one argumentThe above error implies that MyPy is not treating the method as a staticmethod.
Your Environment
- Mypy version used: 0.971
- Mypy command-line flags: N/A
- Mypy configuration options from
mypy.ini(and other config files): N/A - Python version used: 3.8.10
- Operating system and version: Linux Mint 20.3 x86_64
Activity
RivenSkaye commentedon Nov 18, 2022
I've noticed this too, for both
staticmethodandclassmethod. Which is a shame, because application order of decorators can cause some funky stuff to happen, including but not limited to straight up errors at runtime, or typehints breaking down to*args: Any, **kwargs: Any.If you do add arguments to the functions, the error changes to a warning that there is no
selforclsargument.Tangentially related, both of those decorators return object instances of their specific classes that are seen as e.g.
staticmethod[int], but trying to hint a function or method as returning such a function causes a runtime error due to the classes not being subscriptable.I think a possible solution would be
typingentries forStaticMethod[](and perhaps fortyping_extensionstoo?) andClassMethod[].As a positive side effect, this might also stop IDE autocomplete from adding
clsas a positional argument in its autocomplete, since the handling of these annotations would be differentMove self argument checks to a later phase - after decorator applicat…