Checking call order across multiple mocks
I needed this answer today, but the example code in the question is really hard to read because the call args are the same as the names of the mocks on the manager and in the scope of the test. Here's the official documentation on this concept, and below is a clearer example for non-robots. All the modules I'm patching are made-up for the sake of the example:
@patch('module.file_reader')
@patch('module.json_parser')
@patch('module.calculator')
def test_main_routine(mock_calculator, mock_json_parser, mock_file_reader):
manager = Mock()
# First argument is the mock to attach to the manager.
# Second is the name for the field on the manager that holds the mock.
manager.attach_mock(mock_file_reader, 'the_mock_file_reader')
manager.attach_mock(mock_json_parser, 'the_mock_json_parser')
manager.attach_mock(mock_calculator, 'the_mock_calculator')
module.main_routine()
expected_calls = [
call.the_mock_file_reader('some file'),
call.the_mock_json_parser('some json'),
call.the_mock_calculator(1, 2)
]
assert manager.mock_calls == expected_calls
Note that you have to use attach_mock
in this case because your mocks were created by patch
. Mocks with names, including those created by patch
, must be attached via attach_mock
for this code to work. You don't have to use attach_mock
if you make your own Mock
objects without names:
def test_main_routine(mock_calculator, mock_json_parser, mock_file_reader):
manager = Mock()
mock_file_reader = Mock()
mock_json_parser = Mock()
mock_calculator = Mock()
manager.the_mock_file_reader = mock_file_reader
manager.the_mock_json_parser = mock_json_parser
manager.the_mock_calculator = mock_calculator
module.main_routine()
expected_calls = [
call.the_mock_file_reader('some file'),
call.the_mock_json_parser('some json'),
call.the_mock_calculator(1, 2)
]
assert manager.mock_calls == expected_calls
If you want a clear assertion failed message when the order or expected calls are missing, use the following assert line instead.
self.assertListEqual(manager.mock_calls, [
call.the_mock_file_reader('some file'),
call.the_mock_json_parser('some json'),
call.the_mock_calculator(1, 2)
])
Define a Mock
manager and attach mocks to it via attach_mock()
. Then check for the mock_calls
:
@patch('module.a')
@patch('module.b')
@patch('module.c')
def test_main_routine(c, b, a):
manager = Mock()
manager.attach_mock(a, 'a')
manager.attach_mock(b, 'b')
manager.attach_mock(c, 'c')
module.main_routine()
expected_calls = [call.a('a'), call.b('b'), call.c('c')]
assert manager.mock_calls == expected_calls
Just to test that it works, change the order of function calls in the main_routine()
function add see that it throws AssertionError
.
See more examples at Tracking order of calls and less verbose call assertions (link is dead; substitute: https://docs.python.org/3/library/unittest.mock.html#attaching-mocks-as-attributes)
Hope that helps.