testing patch feature from python mock

.gitignore

*.pyc

global_.py

HARD_DEPENDENCY = "Hard dependency"

implementation.py

from global_ import HARD_DEPENDENCY


def sut():
    return HARD_DEPENDENCY

tests.py

"""This module runs unittest to try out patch feature from python mock."""

import unittest

from mock import patch

from implementation import sut
from global_ import HARD_DEPENDENCY


class PatchFeatureTest(unittest.TestCase):

    def test(self):
        self.assertEqual("Hard dependency", HARD_DEPENDENCY)
        with patch('implementation.HARD_DEPENDENCY', "mock!"):
            self.assertEqual("mock!", sut())
            self.assertEqual("Hard dependency", HARD_DEPENDENCY)
        self.assertEqual("Hard dependency", HARD_DEPENDENCY)


if __name__ == '__main__':
    unittest.main()