Unit-testing Python: Mocking function calls inside function

Question

I have a django view like this

# Django view

from some_module import f2
def f1(request, version):
    # some code

    f2(**kargs)

    # more code
    return HTTPResponse(response)

The function f2 is in another module

# some_module
def f2(**kargs):
    # some code

The Django view is part of an API so, the request and response are in json

How do I :

1. write a unit test for this function while mocking the request
2. mock f2, which is a database based function and avoid database connections entirely

EDIT:

The database I am using is Cassandra, so I cannot use django.db

Answer 1

You can use @mock.patch decorator to mock f2() method in your unittests.

import mock
import some_module
from django.test import TestCase

def mocked_f2(**kargs):
    return 'Hey'

class YourTestCase(TestCase):

    @mock.patch('some_module.f2', side_effect=mocked_f2)
    def test_case(self, mocked):
        print some_module.f2()  # will print: 'Hey'

In this case each time you call f2() in your code, mocked_f2 will be called.