def test_is_compare(): """Ensures that `is` operator works correctly.""" some_container = Some(1) assert Nothing.bind(lambda state: state) is Nothing assert some_container.rescue(lambda: Some('fix')) is some_container assert some_container is not Some(1)
def test_bind_nothing(): """Ensures that left identity works for Nothing container.""" def factory(inner_value) -> Maybe[int]: return Some(1) bound = Nothing.bind(factory) assert bound == Nothing assert str(bound) == '<Nothing>'