invalid-*-returned false positives in stubs

[jolaf]

The following file A.pyi:

from typing import Any, Iterator

class A:
    def __len__(self) -> int: ...
    def __hash__(self) -> int: ...
    def __index__(self) -> int: ...
    def __iter__(self) -> Iterator[Any]: ...

produces the following output:

$ pylint A.pyi
************* Module A
A.pyi:4: [E0303(invalid-length-returned), A.__len__] __len__ does not return non-negative integer
A.pyi:5: [E0309(invalid-hash-returned), A.__hash__] __hash__ does not return int
A.pyi:6: [E0305(invalid-index-returned), A.__index__] __index__ does not return int
A.pyi:7: [E0301(non-iterator-returned), A.__iter__] __iter__ returns non-iterator

$ pylint --version
pylint 2.9.5
astroid 2.6.5
Python 3.8.10 (default, Jun  2 2021, 10:49:15) 
[GCC 9.4.0]

These looks like false positives to me.

[OJFord]

Can't speak for the others, but the __iter__ one seems to be a regression.

[jolaf]

It looks to me that all the return type checks should not be performed if method body is not defined or the method throws any unconditional exception.

[ntjess]

Is this related to microsoft/vscode-python#16807, or should I open a new issue here for that problem?

[Pierre-Sassoulas]

@ntjess it look like it's related.

[jolaf]

Thanks @DanielNoord @cdce8p !!