Description

Stubtest currently emits false-positive errors on most of the stdlib enums in typeshed, due to this behaviour:

>>> from enum import Enum
>>> class Foo(Enum):
...     BAR = 1
...
>>> Foo.BAR.value
1
>>> Foo.BAR.value = 5
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\alexw\AppData\Local\Programs\Python\Python310\lib\types.py", line 187, in __set__
    raise AttributeError("can't set attribute")
AttributeError: can't set attribute
>>> Foo.value
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\alexw\AppData\Local\Programs\Python\Python310\lib\enum.py", line 437, in __getattr__
    raise AttributeError(name) from None
AttributeError: value

The value property exists on enum classes, but stubtest can't see it due to some magic the enum module does to make value raise an AttributeError if you try to access it on the class itself, rather than on an enum member. We can avoid these false-positive errors by falling back to getattr_static if the attribute can't be found using getattr.

Output from running typeshed's stubtest_stdlib.py, with this patch checked out, relative to running the same test with mypy master checked out:

+ note: unused allowlist entry enum.Enum.name
+ note: unused allowlist entry enum.Enum.value
+ note: unused allowlist entry enum.Flag.name
+ note: unused allowlist entry enum.Flag.value
+ note: unused allowlist entry enum.IntEnum.value

Test Plan

I added a test.