Mock Method Was Called

method_was_called.py

import itertools

class MethodWasCalled(object):

    calls = []

    def __init__(self, fn):
        self.fn = fn
    def __call__(self, *args, **kwargs):
        self.calls.append([args, kwargs])
        return self.fn(*args, **kwargs)
    def was_called(self):
        return len(self.calls) > 0
    def called_with(self, *args, **kwargs):
        for call in self.calls:
            success = True
            for a, b in itertools.izip_longest(args, call[0]):
                if a != b:
                    success = False
            for (a_k, a_v), (b_k, b_v) in itertools.izip_longest(kwargs.iteritems(), call[1].iteritems()):
                if a_v != b_v or a_k != b_k:
                    success = False
            if success:
                return True
        return False

def some_method(a, b, c=None):
    return (a, b, c)

if __name__ == '__main__':
    mocked = MethodWasCalled(some_method)
    a = mocked("a", "b", c="c")
    b = mocked("d", "e", c="f")

    assert mocked.was_called()
    assert mocked.called_with("a", "b", c="c")
    assert mocked.called_with("d", "e", c="f")
    assert not mocked.called_with("d", "e", c="g")