Karthikeyan Singaravelan <tir.kar...@gmail.com> added the comment:
mock.Mock doesn't do signature validation by default for constructor and
methods. This is expected. create_autospec [0] should be used to make sure the
signature is validated.'
import dataclasses
import unittest.mock
@dataclasses.dataclass
class Foo:
name: str
baz: float
bar: int = 12
FooMock = unittest.mock.create_autospec(Foo)
fooMock = FooMock() # Will fail now since it's specced
➜ cpython git:(master) ./python.exe ../backups/bpo36580.py
Traceback (most recent call last):
File "../backups/bpo36580.py", line 11, in <module>
fooMock = FooMock() # should fail: Foo.__init__ takes two arguments
File
"/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/unittest/mock.py",
line 984, in __call__
_mock_self._mock_check_sig(*args, **kwargs)
File
"/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/unittest/mock.py",
line 103, in checksig
sig.bind(*args, **kwargs)
File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/inspect.py",
line 3021, in bind
return args[0]._bind(args[1:], kwargs)
File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/inspect.py",
line 2936, in _bind
raise TypeError(msg) from None
TypeError: missing a required argument: 'name'
On the other hand 'name' in dir(FooMock) doesn't have the attributes (name and
baz) present I suppose they are constructed dynamically when an object is
created from Foo since they are present in dir(Foo()) and mock is not able to
detect them? mock.create_autospec does an initial pass of dir(Foo) to copy the
attributes [1] and perhaps it's not able to copy name and bar while baz is
copied. Below are for FooMock = create_autospec(Foo) . So 'name' in dir(Foo) is
False for dataclasses. Is this a known behavior?
dir(Foo)
['__annotations__', '__class__', '__dataclass_fields__',
'__dataclass_params__', '__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__', 'bar']
dir(Foo(1, 2))
['__annotations__', '__class__', '__dataclass_fields__',
'__dataclass_params__', '__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__', 'bar', 'baz',
'name']
dir(create_autospec(Foo))
['__annotations__', '__class__', '__dataclass_fields__',
'__dataclass_params__', '__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__', 'assert_any_call',
'assert_called', 'assert_called_once', 'assert_called_once_with',
'assert_called_with', 'assert_has_calls', 'assert_not_called', 'attach_mock',
'bar', 'call_args', 'call_args_list', 'call_count', 'called', 'configure_mock',
'method_calls', 'mock_add_spec', 'mock_calls', 'reset_mock', 'return_value',
'side_effect']
print('name' in dir(fooMock)) # False
print('baz' in dir(fooMock)) # False
print('bar' in dir(fooMock)) # True
[0]
https://docs.python.org/3/library/unittest.mock.html#unittest.mock.create_autospec
[1]
https://github.com/python/cpython/blob/0e10766574f4e287cd6b5e5860a1ca75488f4119/Lib/unittest/mock.py#L2263
----------
nosy: +xtreak
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Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue36580>
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