Patching many functions for all test case methods

test_complex_function.py

from unittest import TestCase
from unittest.mock import patch, call

from my_project.module import complex_function


class SomeTestCase(TestCase):
    # in this test case every method will mock calls to func_1, func_2, func_3, func_4
    def setUp(self):
        super().setUp()
        self.patchers = []

        def get_mock(target, autospec=True):
            patcher = patch(target, autospec=autospec)
            self.patchers.append(patcher)
            return patcher.start()

        self.func_1_mock = get_mock("my_project.module.func_1")
        self.func_2_mock = get_mock("my_project.module.func_1")
        self.func_3_mock = get_mock("my_project.module.func_1")
        self.func_4_mock = get_mock("my_project.module.func_1")

    def tearDown(self):
        super().tearDown()

        for patcher in self.patchers:
            patcher.stop()

    def test_with_multiple_mocks(self):
        self.func_1_mock.return_value = 1
        self.func_2_mock.return_value = 2
        self.func_3_mock.return_value = 3
        self.func_4_mock.return_value = 4

        result = complex_function()

        #... asserts about result ...

        self.func_1_mock.assert_called_once_with(arg1=1, arg2=2)
        self.func_2_mock.assert_called_once_with()
        
        self.assertFalse(self.func_3_mock.called)
        
        self.func_3_mock.assert_has_calls(calls=[call(21), call(23)])