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>'