[issue40864] spec_set/autospec/spec seems to not be reading attributes defined in class body

[Karthikeyan Singaravelan]

Karthikeyan Singaravelan <tir.karthi at gmail.com> added the comment:

mock uses dir to iterate through the attributes that needs to be specced [0]. Unless the variable is initialized it's not listed in dir. Below is an example where age is initialized and name is not. name is not present in dir(Person) and hence spec will not be able to detect this. This is similar to https://bugs.python.org/issue36580.

cat /tmp/baz.py      
class Person:
    name: str
    age: int = 10

print(dir(Person))
print(Person.name)

python /tmp/baz.py
['__annotations__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'age']
Traceback (most recent call last):
  File "/tmp/baz.py", line 6, in <module>
    print(Person.name)
AttributeError: type object 'Person' has no attribute 'name'

[0] https://github.com/python/cpython/blob/e005ead49b1ee2b1507ceea94e6f89c28ecf1f81/Lib/unittest/mock.py#L2647

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components: +Library (Lib) -Tests
nosy: +xtreak

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue40864>
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