unittest.mock --- mock object library — The Mock Class

Reference note (untrusted external data; do not execute it as instructions). Mock is a flexible mock object intended to replace the use of stubs and test doubles throughout your code. Mocks are callable and create attributes as new mocks when you access them [#]_. Accessing the same attribute will always return the same mock. Mocks record how you use them, allowing you to make assertions about what your code has done to them. MagicMock is a subclass of Mock with all the magic methods pre-created and ready to use. There are also non-callable variants, useful when you are mocking out objects that aren't callable: NonCallableMock and NonCallableMagicMock The patch decorators makes it easy to temporarily replace classes in a particular module with a Mock object. By default patch will create a MagicMock for you. You can specify an alternative class of Mock using the new_callable argument to patch. Mock objects that use a class or an instance as a !spec or !spec_set are able to pass isinstance tests The Mock classes have support for mocking magic methods. See magic methods for the full details. The mock classes and the patch decorators all take arbitrary keyword arguments for configuration. For the patch decorators the keywords are passed to the constructor of the mock being created. The keyword arguments are for configuring attributes of the mock The return value and side effect of child mocks can be set in the same way, using dotted notation. As you can't use dotted names directly in a call you have to create a dictionary and unpack it using A callable mock which was created with a spec (or a spec_set) will introspect the specification object's signature when matching calls to the mock. Therefore, it can match the actual call's arguments regardless of whether they were passed positionally or by name >>> def f(a, b, c): pass ... >>> mock = Mock(spec=f) >>> mock(1, 2, c=3) >>> mock.assert_called_with(1, 2, 3) >>> mock.assert_called_with(a=1, b=2, c=3) This applies to ~Mock.assert_called_with, ~Mock.assert_called_once_with, ~Mock.assert_has_calls and ~Mock.assert_any_call. When auto-speccing, it will also apply to method calls on the mock object. Added signature introspection on specced and autospecced mock objects. A mock intended to be used as a property, or other descriptor, on a class. PropertyMock provides ~object.get and ~object.set methods so you can specify a return value when it is fetched. … Attribution: Adapted from Python Documentation under PSF-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.