sealedmock 0.2.0

Install

pip install sealedmock

Usage

Given you have a file like:

import urllib2

class SampleCodeClass(object):
    """This is sample code"""
    def calling_urlopen(self):
        return urllib2.urlopen("http://chooserandom.com")

    def calling_splithost(self):
        return urllib2.splithost("//host:port/path")

You can write a test like:

@patch("tests.sample_code.urllib2")
def test_using_decorator(mock):
        sample = sample_code.SampleCodeClass()
        mock.urlopen.return_value = 2

        mock.sealed = True  # No new attributes can be declared

        # calling urlopen succeeds as mock.urlopen has been defined
        assert sample.calling_urlopen()

        # This will fail as mock.splithost has not been defined
        sample.calling_splithost()

If you use an common Mock the second part will pass as it will create a mock for you and return it. With SealedMock you can choose when to stop that beaviour.

This is recursive so you can write:

@patch("sample_code.secret")
def test_recursive(mock):
        sample = sample_code.SampleCodeClass()
        mock.secret.call1.call2.call3.return_value = 1

        # If secret is not used as specified above it will fail
        # ex: if do_stuff also calls secret.call1.call9
        sample.do_stuff()

It also prevents typos on tests if used like this:

@patch("sample_code.secret")
def test_recursive(mock):
        sample = sample_code.SampleCodeClass()

        sample.do_stuff()

        mock.sealed = True
        mock.asert_called_with(1)
        # Note the typo in asert (should be assert)
        # Sealed mock will rise, normal mock won't