Mocking a global variable

Question

I\'ve been trying to implement some unit tests for a module. An example module named alphabet.py is as follows:

import database

def length_letters(         


        

Answer 1

Try this:

import unittests  
import alphabet   
from unittest.mock import patch   


class TestAlphabet(unittest.TestCase): 
    def setUp(self):
        self.mock_letters = mock.patch.object(
            alphabet, 'letters', return_value=['a', 'b', 'c']
        )

    def test_length_letters(self):
        with self.mock_letters:
            self.assertEqual(3, alphabet.length_letters())

    def test_contains_letter(self):
        with self.mock_letters:
            self.assertTrue(alphabet.contains_letter('a'))

You need to apply the mock while the individual tests are actually running, not just in setUp(). We can create the mock in setUp(), and apply it later with a with ... Context Manager.