def test_published_events_are_appended_to_event_store(self):
# Check the event store's append method has NOT been called.
assert isinstance(self.repository, AbstractEntityRepository)
self.assertEqual(0, self.repository.take_snapshot.call_count)
# Publish a versioned entity event.
entity_id = uuid4()
domain_event1 = VersionedEntity.Event(
originator_id=entity_id,
originator_version=0,
)
domain_event2 = VersionedEntity.Event(
originator_id=entity_id,
originator_version=1,
)
# Check take_snapshot is called once for each event.
publish(domain_event1)
self.assertEqual(0, self.repository.take_snapshot.call_count)
publish(domain_event2)
self.assertEqual(1, self.repository.take_snapshot.call_count)
# Check take_snapshot is called once for each list.
publish([domain_event1, domain_event2])
self.assertEqual(2, self.repository.take_snapshot.call_count)
def test_published_events_are_appended_to_event_store(self):
# Check the event store's append method has NOT been called.
assert isinstance(self.event_store, AbstractEventStore)
self.assertEqual(0, self.event_store.append.call_count)
# Publish a versioned entity event.
entity_id = uuid4()
domain_event1 = VersionedEntity.Event(originator_id=entity_id,
originator_version=0)
publish(domain_event1)
# Check the append method has been called once with the domain event.
self.event_store.append.assert_called_once_with(domain_event1)
# Publish a timestamped entity event (should be ignored).
domain_event2 = TimestampedEntity.Event(originator_id=entity_id)
publish(domain_event2)
# Check the append() has still only been called once with the first domain event.
self.event_store.append.assert_called_once_with(domain_event1)
def test_attribute(self):
# Check we get an error when called with something other than a function.
self.assertRaises(ProgrammingError, attribute, 'not a getter')
self.assertRaises(ProgrammingError, attribute, 123)
self.assertRaises(ProgrammingError, attribute, None)
# Call the decorator with a function.
getter = lambda: None
p = attribute(getter)
# Check we got a property object.
self.assertIsInstance(p, property)
# Check the property object has both setter and getter functions.
self.assertTrue(p.fset)
self.assertTrue(p.fget)
# Pretend we decorated an object.
entity_id = uuid4()
o = VersionedEntity(originator_id=entity_id, originator_version=0)
o.__dict__['_<lambda>'] = 'value1'
# Call the property's getter function.
value = p.fget(o)
self.assertEqual(value, 'value1')
# Call the property's setter function.
p.fset(o, 'value2')
# Check the attribute has changed.
value = p.fget(o)
self.assertEqual(value, 'value2')
# Check the property's getter function isn't the getter function we passed in.
self.assertNotEqual(p.fget, getter)
# Define a class that uses the decorator.
class Aaa(VersionedEntity):
"An event sourced entity."
def __init__(self, a, *args, **kwargs):
super(Aaa, self).__init__(*args, **kwargs)
self._a = a
@attribute
def a(self):
"A mutable event sourced property."
# Instantiate the class and check assigning to the property publishes an event and updates the object state.
published_events = []
subscription = (lambda x: True, lambda x: published_events.append(x))
subscribe(*subscription)
entity_id = uuid4()
try:
aaa = Aaa(originator_id=entity_id, originator_version=1, a=1)
self.assertEqual(aaa.a, 1)
aaa.a = 'value1'
self.assertEqual(aaa.a, 'value1')
finally:
unsubscribe(*subscription)
# Check an event was published.
self.assertEqual(len(published_events), 1)
# Check the published event was an AttributeChanged event, with the expected attribute values.
published_event = published_events[0]
self.assertIsInstance(published_event, AttributeChanged)
self.assertEqual(published_event.name, '_a')
self.assertEqual(published_event.value, 'value1')
self.assertTrue(published_event.originator_version, 1)
self.assertEqual(published_event.originator_id, entity_id)
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = Example.__create__(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the instance is equal to itself.
self.assertEqual(example1, example1)
# Check the instance is equal to a clone of itself.
clone = object.__new__(type(example1))
clone.__dict__.update(example1.__dict__)
self.assertEqual(example1, clone)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the TimestampedVersionedEntity class.
self.assertTrue(example1.id)
self.assertEqual(example1.__version__, 0)
self.assertTrue(example1.__created_on__)
self.assertLess(example1.__created_on__, time.time())
self.assertGreater(example1.__created_on__, time.time() - 1)
self.assertTrue(example1.__last_modified__)
self.assertEqual(example1.__created_on__, example1.__last_modified__)
# Test the datetime_from_timestamp() converts ok.
tt = time.time()
dt = datetime.datetime.utcnow()
self.assertEqual(datetime_from_timestamp(tt).hour, dt.hour)
# Check can get datetime from timestamps, and it corresponds to UTC.
dt = datetime_from_timestamp(example1.__created_on__)
self.assertLess(dt, datetime.datetime.utcnow())
self.assertGreater(dt,
datetime.datetime.utcnow() - datetime.timedelta(1))
# Check a different type with the same values is not "equal" to the first.
class Subclass(Example):
pass
other = object.__new__(Subclass)
other.__dict__.update(example1.__dict__)
self.assertEqual(example1.__dict__, other.__dict__)
self.assertNotEqual(example1, other)
# Check a second instance with the same values is not "equal" to the first.
example2 = create_new_example(a=1, b=2)
self.assertEqual(type(example1), type(example2))
self.assertNotEqual(example1, example2)
# Check entity not hashable.
with self.assertRaises(TypeError):
hash(example1)
# Setup the repo.
repo = ExampleRepository(self.entity_event_store)
# Check the example entities can be retrieved from the example repository.
entity1 = repo[example1.id]
self.assertIsInstance(entity1, Example)
self.assertEqual(1, entity1.a)
self.assertEqual(2, entity1.b)
entity2 = repo[example2.id]
self.assertIsInstance(entity2, Example)
self.assertEqual(1, entity2.a)
self.assertEqual(2, entity2.b)
# Check the entity can be updated.
entity1.a = 100
self.assertEqual(100, repo[entity1.id].a)
entity1.b = -200
self.assertEqual(-200, repo[entity1.id].b)
self.assertEqual(repo[entity1.id].__created_on__,
entity1.__created_on__)
self.assertEqual(repo[entity1.id].__last_modified__,
entity1.__last_modified__)
self.assertNotEqual(entity1.__last_modified__, entity1.__created_on__)
self.assertEqual(0, entity1.count_heartbeats())
entity1.beat_heart()
entity1.beat_heart()
entity1.beat_heart()
self.assertEqual(3, entity1.count_heartbeats())
self.assertEqual(3, repo[entity1.id].count_heartbeats())
# Check the entity can publish multiple events simultaneously.
entity1.beat_heart(number_of_beats=3)
self.assertEqual(6, repo[entity1.id].count_heartbeats())
# Check the entity can be discarded.
entity1.__discard__()
# Check the repo now raises a KeyError.
self.assertRaises(RepositoryKeyError, repo.__getitem__, entity1.id)
# Check the entity can't be discarded twice.
self.assertRaises(AssertionError, entity1.__discard__)
# Should fail to validate event with wrong entity ID.
with self.assertRaises(OriginatorIDError):
VersionedEntity.Event(
originator_id=uuid4(),
originator_version=0,
).__check_obj__(entity2)
# Should fail to validate event with wrong entity version.
with self.assertRaises(OriginatorVersionError):
VersionedEntity.Event(
originator_id=entity2.id,
originator_version=0,
__previous_hash__=entity2.__head__,
).__check_obj__(entity2)
# Should validate event with correct entity ID and version.
VersionedEntity.Event(
originator_id=entity2.id,
originator_version=entity2.__version__ + 1,
__previous_hash__=entity2.__head__,
).__check_obj__(entity2)
# Check an entity cannot be reregistered with the ID of a discarded entity.
replacement_event = Example.Created(
originator_id=entity1.id,
a=11,
b=12,
originator_topic=get_topic(Example),
)
with self.assertRaises(ConcurrencyError):
publish(event=replacement_event)
def test_attribute(self):
# Check we get an error when called with something other than a function.
self.assertRaises(ProgrammingError, attribute, 'not a getter')
self.assertRaises(ProgrammingError, attribute, 123)
self.assertRaises(ProgrammingError, attribute, None)
# Call the decorator with a function.
getter = lambda: None
p = attribute(getter)
# Check we got a property object.
self.assertIsInstance(p, property)
# Check the property object has both setter and getter functions.
self.assertTrue(p.fset)
self.assertTrue(p.fget)
# Pretend we decorated an object.
entity_id = uuid4()
o = VersionedEntity(id=entity_id, __version__=0)
o.__dict__['_<lambda>'] = 'value1'
# Call the property's getter function.
value = p.fget(o)
self.assertEqual(value, 'value1')
# Call the property's setter function.
p.fset(o, 'value2')
# Check the attribute has changed.
value = p.fget(o)
self.assertEqual(value, 'value2')
# Check the property's getter function isn't the getter function we passed in.
self.assertNotEqual(p.fget, getter)
# Define a class that uses the decorator.
class Aaa(VersionedEntity):
"An event sourced entity."
def __init__(self, a, *args, **kwargs):
super(Aaa, self).__init__(*args, **kwargs)
self._a = a
@attribute
def a(self):
"A mutable event sourced property."
# Instantiate the class and check assigning to the property publishes an event and updates the object state.
published_events = []
subscription = (lambda x: True, lambda x: published_events.append(x))
subscribe(*subscription)
entity_id = uuid4()
try:
aaa = Aaa(id=entity_id, __version__=1, a=1)
self.assertEqual(aaa.a, 1)
aaa.a = 'value1'
self.assertEqual(aaa.a, 'value1')
finally:
unsubscribe(*subscription)
# Check an event was published.
self.assertEqual(len(published_events), 1)
# Check the published event was an AttributeChanged event, with the expected attribute values.
published_event = published_events[0]
self.assertIsInstance(published_event, AttributeChanged)
self.assertEqual(published_event.name, '_a')
self.assertEqual(published_event.value, 'value1')
self.assertTrue(published_event.originator_version, 1)
self.assertEqual(published_event.originator_id, entity_id)
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = create_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the instance is equal to itself.
self.assertEqual(example1, example1)
# Check the instance is equal to a clone of itself.
clone = object.__new__(type(example1))
clone.__dict__.update(example1.__dict__)
self.assertEqual(example1, clone)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the TimestampedVersionedEntity class.
self.assertTrue(example1.id)
self.assertEqual(1, example1.version)
self.assertTrue(example1.created_on)
self.assertTrue(example1.last_modified)
self.assertEqual(example1.created_on, example1.last_modified)
# Check a different type with the same values is not "equal" to the first.
class Subclass(Example):
pass
other = object.__new__(Subclass)
other.__dict__.update(example1.__dict__)
self.assertEqual(example1.__dict__, other.__dict__)
self.assertNotEqual(example1, other)
# Check a second instance with the same values is not "equal" to the first.
example2 = create_new_example(a=1, b=2)
self.assertEqual(type(example1), type(example2))
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepository(self.entity_event_store)
# Check the example entities can be retrieved from the example repository.
entity1 = repo[example1.id]
self.assertIsInstance(entity1, Example)
self.assertEqual(1, entity1.a)
self.assertEqual(2, entity1.b)
entity2 = repo[example2.id]
self.assertIsInstance(entity2, Example)
self.assertEqual(1, entity2.a)
self.assertEqual(2, entity2.b)
# Check the entity can be updated.
entity1.a = 100
self.assertEqual(100, repo[entity1.id].a)
entity1.b = -200
self.assertEqual(-200, repo[entity1.id].b)
self.assertEqual(repo[entity1.id].created_on, entity1.created_on)
self.assertEqual(repo[entity1.id].last_modified, entity1.last_modified)
self.assertNotEqual(entity1.last_modified, entity1.created_on)
self.assertEqual(0, entity1.count_heartbeats())
entity1.beat_heart()
entity1.beat_heart()
entity1.beat_heart()
self.assertEqual(3, entity1.count_heartbeats())
self.assertEqual(3, repo[entity1.id].count_heartbeats())
# Check the entity can publish multiple events simultaneously.
entity1.beat_heart(number_of_beats=3)
self.assertEqual(6, repo[entity1.id].count_heartbeats())
# Check the entity can be discarded.
entity1.discard()
# Check the repo now raises a KeyError.
self.assertRaises(RepositoryKeyError, repo.__getitem__, entity1.id)
# Check the entity can't be discarded twice.
self.assertRaises(AssertionError, entity1.discard)
# Should fail to validate event with wrong entity ID.
with self.assertRaises(MismatchedOriginatorIDError):
entity2._validate_originator(
VersionedEntity.Event(originator_id=uuid4(),
originator_version=0))
# Should fail to validate event with wrong entity version.
with self.assertRaises(MismatchedOriginatorVersionError):
entity2._validate_originator(
VersionedEntity.Event(
originator_id=entity2.id,
originator_version=0,
))
# Should validate event with correct entity ID and version.
entity2._validate_originator(
VersionedEntity.Event(
originator_id=entity2.id,
originator_version=entity2.version,
))
# Check an entity cannot be reregistered with the ID of a discarded entity.
replacement_event = Example.Created(originator_id=entity1.id,
a=11,
b=12)
with self.assertRaises(ConcurrencyError):
publish(event=replacement_event)