def test_init(self):
either = Either(1)
self.assertEqual(1, either.value)
self.assertIsNone(either.error)
error_either = Either(None, Exception("Foo"))
self.assertIsNone(error_either.value)
self.assertEqual("Foo", error_either.error.args[0])
def get_season_ticket(destination: Station,
origin: Station) -> Either[SeasonTicket]:
response = Either.fromfunction(_make_request, origin.sid, destination.sid)
return response >> \
_extract_weekly_fare >> \
_calculate_annual_fare >> \
_make_season_ticket
def get_update(self, destination: Station, origin: Station) -> Either[JourneyCosts]:
season_ticket = self._get_season_ticket(destination, origin)
return Either.fromfunction(self._add_cheapest_travelcard, destination, origin, season_ticket)
def get_peak_journey_time(api_key: str, destination: Station,
origin: Station) -> Either[int]:
return Either(date.today()) >> \
_get_peak_time >> \
_directions_request(api_key, origin, destination) >> \
_extract_journey_time
def test_bind_with_error_func(self):
def _raiser(x): raise Exception("Foo")
either = Either(1).bind(_raiser)
self.assertIsNone(either.value)
self.assertEqual("Foo", either.error.args[0])
def test_bind_using_rshift(self):
either = Either(1) >> (lambda x: x + 1)
self.assertEqual(2, either.value)
self.assertIsNone(either.error)
def test_bind_with_error(self):
either = Either(None, Exception("Foo")).bind(lambda x: x + 1)
self.assertIsNone(either.value)
self.assertEqual("Foo", either.error.args[0])
def test_bind(self):
either = Either(1).bind(lambda x: x + 1)
self.assertEqual(2, either.value)
self.assertIsNone(either.error)
def test_is_error(self):
self.assertFalse(Either(1).is_error)
self.assertTrue(Either(None, Exception()).is_error)
def test_error_type(self):
self.assertEqual(Exception, Either(None, Exception()).error_type)
self.assertEqual(KeyError, Either(None, KeyError()).error_type)
self.assertEqual(type(None), Either(1, None).error_type)
def test_fromfunction_with_error(self):
def _raiser(): raise Exception("Foo")
either = Either.fromfunction(_raiser)
self.assertIsNone(either.value)
self.assertEqual("Foo", either.error.args[0])
def test_fromfunction(self):
either = Either.fromfunction(lambda x: x, 2)
self.assertEqual(2, either.value)
self.assertIsNone(either.error)