bpo-28911: Clarify the behaviour of assert_called_once_with. (#252)
(cherry picked from commit 9d56b34af2efc4e266bf3ae62da5cd2e422a42be)
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
index c6d0ec9..a552cbf 100644
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -303,14 +303,14 @@
.. method:: assert_called_once_with(*args, **kwargs)
- Assert that the mock was called exactly once and with the specified
- arguments.
+ Assert that the mock was called exactly once and that that call was
+ with the specified arguments.
>>> mock = Mock(return_value=None)
>>> mock('foo', bar='baz')
>>> mock.assert_called_once_with('foo', bar='baz')
- >>> mock('foo', bar='baz')
- >>> mock.assert_called_once_with('foo', bar='baz')
+ >>> mock('other', bar='values')
+ >>> mock.assert_called_once_with('other', bar='values')
Traceback (most recent call last):
...
AssertionError: Expected 'mock' to be called once. Called 2 times.
@@ -322,7 +322,8 @@
The assert passes if the mock has *ever* been called, unlike
:meth:`assert_called_with` and :meth:`assert_called_once_with` that
- only pass if the call is the most recent one.
+ only pass if the call is the most recent one, and in the case of
+ :meth:`assert_called_once_with` it must also be the only call.
>>> mock = Mock(return_value=None)
>>> mock(1, 2, arg='thing')