def test_retain_delta_lengths(self):
delta = Delta().retain(1)
assert delta.length() == 1
delta = Delta().retain(10)
assert delta.length() == 10
delta = Delta().retain(10).retain(10).retain(10)
assert delta.length() == 30
def test_insert_lengths(self):
delta = Delta().insert('test')
assert delta.length() == 4
delta = Delta().insert(1)
assert delta.length() == 1
delta = Delta().insert({'url': 'https://google.com/'})
assert delta.length() == 1
def test_delete_delta_lengths(self):
delta = Delta().delete(1)
assert delta.length() == 1
delta = Delta().delete(10)
assert delta.length() == 10
delta = Delta().delete(10).delete(10).delete(10)
assert delta.length() == 30
