def test_simple_service(self):
ms = MeasurementService()
class SimpleService:
def __init__(self):
self.units = ['milimeter', 'kilometer', 'centimeter', "meter"]
def is_valid_units_string(self, unit):
if unit in self.units:
return True
return False
def units_equivalent(self, units1, units2):
if self.is_valid_units_string(units1) and self.is_valid_units_string(units2):
return True
return False
register_measurement_info_service(SimpleService())
self.assertTrue(ms.is_valid_units_string("meter"))
self.assertFalse(ms.is_valid_units_string("pascal"))
self.assertTrue(ms.units_equivalent("meter", "centimeter"))
self.assertTrue(ms.units_equivalent("kilometer", "milimeter"))
self.assertFalse(ms.units_equivalent("kilometer", "kilogram"))
# Using this mechanism you can add different measurement sources, covering
# different types of measurement units::
class AnotherService(SimpleService):
def __init__(self):
self.units = ['gram', 'kilogram']
register_measurement_info_service(AnotherService())
self.assertTrue(ms.is_valid_units_string("gram"))
self.assertTrue(ms.is_valid_units_string("milimeter"))
self.assertTrue(ms.units_equivalent("kilogram", "gram"))
self.assertTrue(ms.units_equivalent("kilometer", "centimeter"))
self.assertFalse(ms.units_equivalent("kilogram", "meter"))
# Using this mechanism, new measurement sources can be included. It's important
# to notice that two sources don't have relation between them. For example, let's
# consider two sources: a source has the only the 'gram' unit and a second source
# have just the 'kilogram' unit provided by themselves. In the real world, they are
# considered equivalent but this cannot be considered true here because they are
# related to different sources. In other hand, they are considered valid
# because each source validate those units::
class LastService(SimpleService):
def __init__(self):
self.units = ['decimeter', 'centigram', 'kilogram']
register_measurement_info_service(LastService())
self.assertTrue(ms.is_valid_units_string("decimeter"))
self.assertTrue(ms.is_valid_units_string("centigram"))
self.assertFalse(ms.units_equivalent('meter', 'decimeter'))
self.assertTrue(ms.units_equivalent('centigram', 'kilogram'))
self.assertTrue(ms.units_equivalent('kilogram', 'gram'))
self.assertFalse(ms.units_equivalent('centigram', 'gram'))
def test_invalid_parameters(self):
ms = MeasurementService()
with self.assertRaises(AttributeError):
ms.is_valid_units_string(4)
with self.assertRaises(AttributeError):
ms.is_valid_units_string(None)
with self.assertRaises(AttributeError):
ms.is_valid_units_string('')
with self.assertRaises(AttributeError):
ms.units_equivalent('centigram', '')
with self.assertRaises(AttributeError):
ms.units_equivalent(None, 'centigram')
def test_invalid_service(self):
ms = MeasurementService()
self.assertFalse(ms.is_valid_units_string('miles'))