Please confirm that this isn't an issue with attrs -- there's a lot of magic behaviour there.

A

It would also be good to try and reproduce it with dataclasses, since they have a lot of the same magic. If it failed with dataclasses then we could look at the interaction between mock and dataclasses more easily than if it requires attrs.

It did fail with dataclasses too, I can supplement an example later, in commute now.

I have updated the title of the issues since it may not be an attrs only problem. @AA-Turner @ericvsmith, thank you.

A similar example with dataclasses below.

from dataclasses import dataclass
from unittest.mock import create_autospec

@dataclass
class DummyClass:
    a: int
    b: int
        
dummy_class = create_autospec(DummyClass)
dummy_class.a

     636         elif self._mock_methods is not None:
    637             if name not in self._mock_methods or name in _all_magics:
--> 638                 raise AttributeError("Mock object has no attribute %r" % name)
    639         elif _is_magic(name):
    640             raise AttributeError(name)

AttributeError: Mock object has no attribute 'a'

That's the same as:

from unittest.mock import create_autospec

class DummyClass:
    pass

dummy_class = create_autospec(DummyClass)
dummy_class.a

Which gives the same error.