Example of usage of python's mock.patch.object()

test_mock_patch_object.py

# encoding: utf-8

import mock


class smtplib(object):
    pass


@mock.patch.object(smtplib, "sendmail", create=True)
def test_mocked_method(*args):
    """
    I want to call smtplib().sendmail("somebody")
    """
    smtplib.sendmail("blah")
    print("test_mocked_method:", smtplib.sendmail.call_args)


@mock.patch.object(smtplib, "sendmail", create=True)
def test_mocked_class_method(*args):
    """
    I want to call smtplib.sendmail("somebody")
    """
    s = smtplib()
    s.sendmail("blah")
    print("test_mocked_class_method:", s.sendmail.call_args)


def test_using_context_manager(*args):
    """
    I want to call smtplib.sendmail("somebody")
    """
    with mock.patch.object(smtplib, "sendmail", create=True) as sendmail:
        sendmail("hoolla", "jalla", "ohyeah")
        sendmail(1, 2, 3)
        print("test_using_context_manager:", sendmail.call_args_list)


"""
Output:
    
('test_mocked_method:', call('blah'))
('test_mocked_class_method:', call('blah'))
('test_using_context_manager:', [call('hoolla', 'jalla', 'ohyeah'), call(1, 2, 3)])
"""

if __name__ == "__main__":
    test_mocked_method()
    test_mocked_class_method()
    test_using_context_manager()