Python Mocking a function from an imported module

Question

I want to understand how to @patch a function from an imported module.

This is where I am so far.

app/mocking.py:

Answer 1

When you are using the patch decorator from the unittest.mock package you are not patching the namespace the module is imported from (in this case app.my_module.get_user_name) you are patching it in the namespace under test app.mocking.get_user_name.

To do the above with Mock try something like the below:

from mock import patch
from app.mocking import test_method 

class MockingTestTestCase(unittest.TestCase):

    @patch('app.mocking.get_user_name')
    def test_mock_stubs(self, test_patch):
        test_patch.return_value = 'Mocked This Silly'
        ret = test_method()
        self.assertEqual(ret, 'Mocked This Silly')

The standard library documentation includes a useful section describing this.