def test_patch_has_no_side_effects(self): a = {'a': 1} copy_of_a = deepcopy(a) b = {'a': 2} d = diff(a, b) self.assertEqual(patch_mapping(a, d), b) self.assertEqual(a, copy_of_a)
def test_unchanged_items_make_no_difference(self): a = {'a': 'a'} b = {'a': 'b'} c = {'a': 'a', 'b': 1, 'c': (3, 4)} d = diff(a, b) self.assertEqual(patch_mapping(c, d), {'a': 'b', 'b': 1, 'c': (3, 4)})