def test_hk_cert_rotation_without_exception(self, mock_CertRotation, cert_rotate_event_mock): # mock cert_rotate object cert_rotate_mock = mock.MagicMock() # mock rotate() rotate_mock = mock.MagicMock() cert_rotate_mock.rotate = rotate_mock mock_CertRotation.return_value = cert_rotate_mock # mock cert_rotate_thread_event.is_set() in the while loop cert_rotate_event_mock.is_set = mock.MagicMock() cert_rotate_event_mock.is_set.side_effect = [False, True] self.assertIsNone(house_keeping.cert_rotation()) mock_CertRotation.assert_called_once_with() self.assertEqual(1, cert_rotate_mock.rotate.call_count)