import pickle

from sentinel import Sentinel

class PlainSentinel(Sentinel): pass


class SentinelCustomRepr(Sentinel):
    repr = '***SentinelRepr***'


def test_repr():
    assert repr(PlainSentinel) == 'PlainSentinel'


def test_pickle():
    s = pickle.dumps(PlainSentinel)
    ps = pickle.loads(s)
    assert ps is PlainSentinel


def test_custom_repr():
    assert repr(SentinelCustomRepr) == '***SentinelRepr***'


def test_sentinel_comes_ready_to_use():
    assert repr(Sentinel) == 'Sentinel'
    s = pickle.dumps(Sentinel)
    ps = pickle.loads(s)
    assert ps is Sentinel