Brainstormed mock for testing salt states and modules

salt_mock.py

class Mock(object):
    def __init__(self):
        history = []
        unmet_expectations = []

    def __call__(self, func, *args, **kwargs):
        """
        Here we can grab a copy of the actual function/state and insert
        the Mock object as __salt__ so the usual calls to
        __salt__['mod.func']() get intercepted and handled by the mock.
        """

    def __getitem__(self, cmd_name):
        
        def mock_function(*args, **kwargs):
            cmd = {
                'cmd': cmd_name,
                'args': args,
                'kwargs': kwargs
            }

            # Find instances of the given cmd in expectations
            candidates = [e for e in self.unmet_expectations if e == cmd]

            # Save some history for future examination
            self.history.append(cmd)

            # This will raise an error if an unexpected command is received
            index = self.unmet_expectations.index(candidates[0])
            expectation = self.unmet_expectations.pop(index)

            # Return the specified reply
            return expectation['reply']

        return mock_function


    def expect(self, cmd, args, kwargs, reply):
        self.unmet_expectations.append({
            'cmd': cmd,
            'args': args,
            'kwargs': kwargs,
            'reply': reply,
        })


class GitTestCase(TestCase):
    def test_clone(self):
        mock = Mock()
        mock.expect('cmd.run',
            args=('/path/to/repo',),
            reply='Cloning into.... blah blah...'
        )
        mock('git.clone', '/path/to/repo')
        self.assertFalse(mock.unmet_expectations)