Python mock test array of functions

Question

Following is my python module my_func.py

def get_data(request):
    function_1(request)

I want to test if function_1 is called with correct request argument inside get_data() function and the following test works fine.

class GetDataTest(TestCase):

    @patch("my_func.function_1", autospec=True)
    def test_get_data(self, function_1_mock):
        request_mock = MagicMock()
        my_func.get_metadata(request_mock)
        function_1_mock.assert_called_once_with(request_mock)

If I change my python module my_func.py to the following where I have an array of functions then I'm struggling how to mock functions individually.

functions = [
    function_1,
    function_2,
    function_3
]

def get_data(request):
    for function in functions:
       function(request)

score 1 · Accepted Answer · answered Jun 04 '20 at 17:40

You don't really need to mock all the functions to test this code. Instead, I would suggest replacing the list content.

First - instead of module variable, you introduce a factory method:

def get_functions():
  return [
    function_1,
    function_2,
    function_3
    ]

def get_data(request):
    for function in get_functions():
       function(request)

then you can mock get_functions() and inject there 1 or more functions (but based on the code I don't see any value in injecting more than one):

class GetDataTest(TestCase):

    @patch("my_func.function_1_mock", autospec=True)
    def test_get_data(self, function_1_mock):
        my_func.get_functions = MagicMock(return_value=[function_1_mock])
        request_mock = MagicMock()
        my_func.get_metadata(request_mock)
        function_1_mock.assert_called_once_with(request_mock)

Python mock test array of functions

1 Answers1