invalid-length-return-type (PLE0303) - false positive when __len__ raises an exception

[DetachHead]

class Foo:
    def __len__(): # error: `__len__` does not return a non-negative integer
        raise Exception

playground

use case

i have a subclass of a type from a 3rd party module that uses __len__ in a very misleading way, so i want to ban people from using it on my subclass:

from typing import override, Never

class Bar(Foo):
    @override
    def __len__() -> Never:
        raise Exception("__len__ is banned on this class")

[charliermarsh]

I believe this is fixed on main.

[charliermarsh]

Via #11017. Sorry about that.