def test_diff_lists_with_only_one_list(self):
lists = [
['a', 'b'],
]
new_elements = diff_lists(lists)
self.assertEqual(new_elements, ['a', 'b'])
def test_diff_lists_when_previous_list_is_none(self):
lists = [
None,
['a', 'c'],
]
new_elements = diff_lists(lists)
self.assertEqual(new_elements, ['a', 'c'])
def test_diff_lists_when_last_list_is_none(self):
lists = [
['a', 'b'],
None,
]
new_elements = diff_lists(lists)
self.assertEqual(new_elements, [])
def test_diff_lists(self):
lists = [
['a', 'b'],
['a', 'c'],
]
new_elements = diff_lists(lists)
self.assertEqual(new_elements, ['c'])