def test_from_london_to_paris(self, mockk):
calculator = FlightCalculator('london', ['paris'])
flights = list(calculator.process())
self.assertEqual(1, len(flights))
self.assertEqual([self.flight1], flights)
def test_nonexistent_destination_city(self, mockk):
with self.assertRaises(NoSuchCity) as ex_context:
list(FlightCalculator('london', ['abra_cadabra']).process())
self.assertEqual(ex_context.exception.args[0],
'abra_cadabra city not found')
def test_empty_departure(self, mockk):
with self.assertRaises(NoSuchCity) as ex_context:
list(FlightCalculator('', ['paris']).process())
self.assertEqual(ex_context.exception.args[0], ' city not found')
def test_empty_destination(self, mockk):
with self.assertRaises(NoDestinationCitiesProvided):
list(FlightCalculator('london', []).process())
def test_with_several_destination_cities(self, mockk):
calculator = FlightCalculator('london', ['paris', 'berlin'])
flights = list(calculator.process())
self.assertEqual(2, len(flights))
self.assertEqual([self.flight1, self.flight2], flights)