@extend_schema_serializer not isolated properly.

[ngnpope]

Hi @tfranzel. This is an extension of the issue in #218 / #554.

Describe the bug

Using @extend_schema_serializer on a class and its subclass causes the subclass to overwrite configuration in the parent. It is likely that this affects all code using set_override(), so also @extend_schema_field also.

To Reproduce

def test_extend_schema_serializer_isolation(no_warnings):
    @extend_schema_serializer(component_name='ABC')
    class OneSerializer(serializers.Serializer):
        pass

    @extend_schema_serializer(component_name='XYZ')
    class TwoSerializer(OneSerializer):
        pass

    assert OneSerializer._spectacular_annotation == {'component_name': 'ABC'}
    assert TwoSerializer._spectacular_annotation == {'component_name': 'XYZ'}

Expected behavior

It seems that set_override() should check to ensure that _spectacular_annotation is cloned to the current class.

[tfranzel]

hey @ngnpope, absolutely! Basically the same root cause as with the other issues. Fortunately this time it's a lot less complicated. We simply need to check if the annotation is derived or belongs to the class itself (__dict__) and make a copy.

Hopefully this was the last isolation issue. 😅

[ngnpope]

Sorry for the delay getting back to you. The fix seems to work nicely. Thanks! 😄

Hopefully this was the last isolation issue. 😅

🤞🏻