class TestCollectionRepo(TestCase):
def setUp(self):
assert_event_handlers_empty()
# Setup the repo, and a persistence subscriber.
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo=stored_event_repo)
self.repo = CollectionRepo(event_store=event_store)
self.ps = PersistenceSubscriber(event_store=event_store)
def tearDown(self):
self.ps.close()
assert_event_handlers_empty()
def test(self):
# Check the collection is not in the repo.
with self.assertRaises(RepositoryKeyError):
_ = self.repo['none']
# Register a new collection.
collection_id = register_new_collection().id
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has zero items.
self.assertEqual(len(collection.items), 0)
# Add item.
item1 = 'item1'
collection.add_item(item1)
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has one item.
self.assertEqual(len(collection.items), 1)
# Remove item.
collection.remove_item(item1)
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has zero items.
self.assertEqual(len(collection.items), 0)
# Discard the collection.
collection.discard()
# Check the collection is not in the repo.
with self.assertRaises(RepositoryKeyError):
_ = self.repo['none']
class TestCollectionRepo(TestCase):
def setUp(self):
assert_event_handlers_empty()
# Setup the repo, and a persistence subscriber.
stored_event_repo = PythonObjectsStoredEventRepository()
event_store = EventStore(stored_event_repo=stored_event_repo)
self.repo = CollectionRepo(event_store=event_store)
self.ps = PersistenceSubscriber(event_store=event_store)
def tearDown(self):
self.ps.close()
assert_event_handlers_empty()
def test(self):
# Check the collection is not in the repo.
with self.assertRaises(RepositoryKeyError):
_ = self.repo['none']
# Register a new collection.
collection_id = register_new_collection().id
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has zero items.
self.assertEqual(len(collection.items), 0)
# Add item.
item1 = 'item1'
collection.add_item(item1)
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has one item.
self.assertEqual(len(collection.items), 1)
# Remove item.
collection.remove_item(item1)
# Check the collection is in the repo.
collection = self.repo[collection_id]
self.assertIsInstance(collection, Collection)
self.assertEqual(collection.id, collection_id)
# Check the collection has zero items.
self.assertEqual(len(collection.items), 0)
# Discard the collection.
collection.discard()
# Check the collection is not in the repo.
with self.assertRaises(RepositoryKeyError):
_ = self.repo['none']
class TestPersistenceSubscriber(unittest.TestCase):
def setUp(self):
# Set up a persistence subscriber with a (mock) event store.
self.event_store = mock.Mock(spec=AbstractEventStore)
self.persistence_subscriber = PersistenceSubscriber(
event_store=self.event_store)
def tearDown(self):
# Close the persistence subscriber.
self.persistence_subscriber.close()
def test_published_events_are_appended_to_event_store(self):
# Check the event store's append method has NOT been called.
self.assertEqual(0, self.event_store.append.call_count)
# Publish a (mock) domain event.
domain_event = mock.Mock(spec=DomainEvent)
publish(domain_event)
# Check the append method HAS been called once with the domain event.
self.event_store.append.assert_called_once_with(domain_event)
class TestPersistenceSubscriber(unittest.TestCase):
def setUp(self):
# Set up a persistence subscriber with a (mock) event store.
self.event_store = mock.Mock(spec=AbstractEventStore)
self.persistence_subscriber = PersistenceSubscriber(event_store=self.event_store)
def tearDown(self):
# Close the persistence subscriber.
self.persistence_subscriber.close()
def test_published_events_are_appended_to_event_store(self):
# Check the event store's append method has NOT been called.
self.assertEqual(0, self.event_store.append.call_count)
# Publish a (mock) domain event.
domain_event = mock.Mock(spec=DomainEvent)
publish(domain_event)
# Check the append method HAS been called once with the domain event.
self.event_store.append.assert_called_once_with(domain_event)
class TestExampleEntity(unittest.TestCase):
def setUp(self):
# Setup the persistence subscriber.
self.event_store = EventStore(PythonObjectsStoredEventRepository())
self.persistence_subscriber = PersistenceSubscriber(
event_store=self.event_store)
def tearDown(self):
self.persistence_subscriber.close()
assert_event_handlers_empty()
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = register_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the EventSourcedEntity class.
self.assertTrue(example1.id)
self.assertEqual(1, example1.version)
self.assertTrue(example1.created_on)
# Check a second instance with the same values is not "equal" to the first.
example2 = register_new_example(a=1, b=2)
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepo(self.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(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 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.
self.assertRaises(
EntityIDConsistencyError, entity2._validate_originator,
DomainEvent(entity_id=entity2.id + 'wrong', entity_version=0))
# Should fail to validate event with wrong entity version.
self.assertRaises(EntityVersionConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id, entity_version=0))
# Should validate event with correct entity ID and version.
entity2._validate_originator(
DomainEvent(entity_id=entity2.id, entity_version=entity2.version))
# Check an entity can be reregistered with the same ID.
replacement_event = Example.Created(entity_id=entity1.id, a=11, b=12)
# replacement = Example.mutate(event=replacement_event)
publish(event=replacement_event)
# Check the replacement entity can be retrieved from the example repository.
replacement = repo[entity1.id]
assert isinstance(replacement, Example)
self.assertEqual(replacement.a, 11)
self.assertEqual(replacement.b, 12)
def test_not_implemented_error(self):
# Define an event class.
class UnsupportedEvent(DomainEvent):
pass
# Check we get an error when attempting to mutate on the event.
self.assertRaises(NotImplementedError, Example.mutate, Example,
UnsupportedEvent('1', '0'))
def test_mutableproperty(self):
# Check we get an error when called with something other than a function.
self.assertRaises(ProgrammingError, mutableproperty, 'not a getter')
self.assertRaises(ProgrammingError, mutableproperty, 123)
self.assertRaises(ProgrammingError, mutableproperty, None)
# Call the decorator with a function.
getter = lambda: None
p = mutableproperty(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.
o = EventSourcedEntity(entity_id='1',
entity_version=0,
domain_event_id=1)
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(EventSourcedEntity):
"An event sourced entity."
def __init__(self, a, *args, **kwargs):
super(Aaa, self).__init__(*args, **kwargs)
self._a = a
@mutableproperty
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 = '1'
try:
aaa = Aaa(entity_id=entity_id,
entity_version=None,
domain_event_id='0',
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, Aaa.AttributeChanged)
self.assertEqual(published_event.name, '_a')
self.assertEqual(published_event.value, 'value1')
self.assertTrue(published_event.domain_event_id)
self.assertEqual(published_event.entity_id, entity_id)
def test_static_mutator_method(self):
self.assertRaises(NotImplementedError, EventSourcedEntity._mutator, 1,
2)
def test_created_mutator_error(self):
self.assertRaises(CreatedMutatorRequiresTypeNotInstance,
created_mutator, mock.Mock(spec=DomainEvent),
'not a class')
class TestExampleEntity(unittest.TestCase):
def setUp(self):
# Setup the persistence subscriber.
self.event_store = EventStore(PythonObjectsStoredEventRepository())
self.persistence_subscriber = PersistenceSubscriber(event_store=self.event_store)
def tearDown(self):
self.persistence_subscriber.close()
assert_event_handlers_empty()
def test_entity_lifecycle(self):
# Check the factory creates an instance.
example1 = register_new_example(a=1, b=2)
self.assertIsInstance(example1, Example)
# Check the properties of the Example class.
self.assertEqual(1, example1.a)
self.assertEqual(2, example1.b)
# Check the properties of the EventSourcedEntity class.
self.assertTrue(example1.id)
self.assertEqual(1, example1.version)
self.assertTrue(example1.created_on)
# Check a second instance with the same values is not "equal" to the first.
example2 = register_new_example(a=1, b=2)
self.assertNotEqual(example1, example2)
# Setup the repo.
repo = ExampleRepo(self.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(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 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.
self.assertRaises(EntityIDConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id+'wrong', entity_version=0)
)
# Should fail to validate event with wrong entity version.
self.assertRaises(EntityVersionConsistencyError,
entity2._validate_originator,
DomainEvent(entity_id=entity2.id, entity_version=0)
)
# Should validate event with correct entity ID and version.
entity2._validate_originator(
DomainEvent(entity_id=entity2.id, entity_version=entity2.version)
)
# Check an entity can be reregistered with the same ID.
replacement_event = Example.Created(entity_id=entity1.id, a=11, b=12)
# replacement = Example.mutate(event=replacement_event)
publish(event=replacement_event)
# Check the replacement entity can be retrieved from the example repository.
replacement = repo[entity1.id]
assert isinstance(replacement, Example)
self.assertEqual(replacement.a, 11)
self.assertEqual(replacement.b, 12)
def test_not_implemented_error(self):
# Define an event class.
class UnsupportedEvent(DomainEvent): pass
# Check we get an error when attempting to mutate on the event.
self.assertRaises(NotImplementedError, Example.mutate, Example, UnsupportedEvent('1', '0'))
def test_mutableproperty(self):
# Check we get an error when called with something other than a function.
self.assertRaises(ProgrammingError, mutableproperty, 'not a getter')
self.assertRaises(ProgrammingError, mutableproperty, 123)
self.assertRaises(ProgrammingError, mutableproperty, None)
# Call the decorator with a function.
getter = lambda: None
p = mutableproperty(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.
o = EventSourcedEntity(entity_id='1', entity_version=0, domain_event_id=1)
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(EventSourcedEntity):
"An event sourced entity."
def __init__(self, a, *args, **kwargs):
super(Aaa, self).__init__(*args, **kwargs)
self._a = a
@mutableproperty
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 = '1'
try:
aaa = Aaa(entity_id=entity_id, entity_version=None, domain_event_id='0', 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, Aaa.AttributeChanged)
self.assertEqual(published_event.name, '_a')
self.assertEqual(published_event.value, 'value1')
self.assertTrue(published_event.domain_event_id)
self.assertEqual(published_event.entity_id, entity_id)
def test_static_mutator_method(self):
self.assertRaises(NotImplementedError, EventSourcedEntity._mutator, 1, 2)
def test_created_mutator_error(self):
self.assertRaises(CreatedMutatorRequiresTypeNotInstance, created_mutator, mock.Mock(spec=DomainEvent), 'not a class')
class LogTestCase(AbstractTestCase):
@property
def stored_event_repo(self):
"""
Returns a stored event repository.
Concrete log test cases will provide this method.
"""
raise NotImplementedError
def setUp(self):
super(LogTestCase, self).setUp()
# Check we're starting clean, event handler-wise.
assert_event_handlers_empty()
# Setup the persistence subscriber.
self.event_store = EventStore(self.stored_event_repo)
self.persistence_subscriber = PersistenceSubscriber(event_store=self.event_store)
self.log_repo = LogRepo(self.event_store)
def tearDown(self):
# Close the persistence subscriber.
self.persistence_subscriber.close()
super(LogTestCase, self).tearDown()
# Check we finished clean, event handler-wise.
assert_event_handlers_empty()
def test_entity_lifecycle(self):
log = self.log_repo.get_or_create(log_name='log1', bucket_size='year')
self.assertIsInstance(log, Log)
self.assertEqual(log.name, 'log1')
self.assertEqual(log.bucket_size, 'year')
# Test get_logger and get_log_reader().
logger = get_logger(log)
self.assertIsInstance(logger, Logger)
message1 = 'This is message 1'
message2 = 'This is message 2'
message3 = 'This is message 3'
message4 = 'This is message 4'
message5 = 'This is message 5'
message6 = 'This is message 6'
event1 = logger.info(message1)
event2 = logger.info(message2)
event3 = logger.info(message3)
halfway = uuid1().hex
event4 = logger.info(message4)
event5 = logger.info(message5)
event6 = logger.info(message6)
# Check we can get all the messages (query running in descending order).
log_reader = get_log_reader(log, event_store=self.event_store)
messages = list(log_reader.get_messages(is_ascending=False))
self.assertEqual(len(messages), 6)
self.assertEqual(messages[0], message6)
self.assertEqual(messages[1], message5)
self.assertEqual(messages[2], message4)
self.assertEqual(messages[3], message3)
self.assertEqual(messages[4], message2)
self.assertEqual(messages[5], message1)
# Check we can get all the messages (query running in ascending order).
messages = list(log_reader.get_messages(is_ascending=True))
self.assertEqual(len(messages), 6)
self.assertEqual(messages[0], message1)
self.assertEqual(messages[1], message2)
self.assertEqual(messages[2], message3)
self.assertEqual(messages[3], message4)
self.assertEqual(messages[4], message5)
self.assertEqual(messages[5], message6)
# Check we can get messages after halfway (query running in descending order).
messages = list(log_reader.get_messages(after=halfway, is_ascending=False))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message6)
self.assertEqual(messages[1], message5)
self.assertEqual(messages[2], message4)
# Check we can get messages until halfway (query running in descending order).
messages = list(log_reader.get_messages(until=halfway, is_ascending=False))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message3)
self.assertEqual(messages[1], message2)
self.assertEqual(messages[2], message1)
# Check we can get messages until halfway (query running in ascending order).
messages = list(log_reader.get_messages(until=halfway, is_ascending=True))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message1)
self.assertEqual(messages[1], message2)
self.assertEqual(messages[2], message3)
# Check we can get messages after halfway (query running in ascending order).
messages = list(log_reader.get_messages(after=halfway, is_ascending=True))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message4)
self.assertEqual(messages[1], message5)
self.assertEqual(messages[2], message6)
# Check we can get last three messages (query running in descending order).
messages = list(log_reader.get_messages(limit=3, is_ascending=False))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message6)
self.assertEqual(messages[1], message5)
self.assertEqual(messages[2], message4)
# Check we can get first three messages (query running in ascending order).
messages = list(log_reader.get_messages(limit=3, is_ascending=True))
self.assertEqual(len(messages), 3)
self.assertEqual(messages[0], message1)
self.assertEqual(messages[1], message2)
self.assertEqual(messages[2], message3)
# Check we can get last line (query running in descending order).
messages = list(log_reader.get_messages(limit=1, after=halfway, is_ascending=False))
self.assertEqual(len(messages), 1)
self.assertEqual(messages[0], message6)
# Check we can get the first line after halfway (query running in ascending order).
messages = list(log_reader.get_messages(limit=1, after=halfway, is_ascending=True))
self.assertEqual(len(messages), 1)
self.assertEqual(messages[0], message4)
# Check we can get the first line before halfway (query running in descending order).
messages = list(log_reader.get_messages(limit=1, until=halfway, is_ascending=False))
self.assertEqual(len(messages), 1)
self.assertEqual(messages[0], message3)
# Check we can get the first line (query running in ascending order).
messages = list(log_reader.get_messages(limit=1, until=halfway, is_ascending=True))
self.assertEqual(len(messages), 1)
self.assertEqual(messages[0], message1)
# Check there isn't a line after the last line (query running in ascending order).
messages = list(log_reader.get_messages(limit=1, after=event6.domain_event_id, is_ascending=True))
self.assertEqual(len(messages), 0)
# Check there is nothing somehow both after and until halfway.
messages = list(log_reader.get_messages(after=halfway, until=halfway))
self.assertEqual(len(messages), 0)
def test_buckets(self):
# Start new log.
log = start_new_log(name='log1', bucket_size='second')
# Write messages across the time interval
start = datetime.datetime.now()
logger = get_logger(log)
number_of_messages = 300
events = []
for i in range(number_of_messages):
message_logged = logger.info(str(i))
events.append(message_logged)
sleep(0.01)
self.assertGreater(datetime.datetime.now() - start, datetime.timedelta(seconds=1))
# Get the messages in descending order.
reader = get_log_reader(log, self.event_store)
messages = list(reader.get_messages(is_ascending=False, page_size=10))
self.assertEqual(len(messages), number_of_messages)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, list(reversed([str(i) for i in range(number_of_messages)])))
# Get the messages in ascending order.
messages = list(reader.get_messages(is_ascending=True, page_size=10))
self.assertEqual(len(messages), number_of_messages)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(number_of_messages)])
# Get a limited number of messages in descending order.
limit = 150
messages = list(reader.get_messages(is_ascending=False, page_size=10, limit=limit))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, list(reversed([str(i) for i in range(number_of_messages)]))[:limit])
# Get a limited number of messages in ascending order.
limit = 150
messages = list(reader.get_messages(is_ascending=True, page_size=10, limit=limit))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(limit)])
# Get a limited number of messages in descending order from the midpoint down.
limit = 110
midpoint = events[150].domain_event_id
messages = list(reader.get_messages(is_ascending=False, page_size=10, limit=limit, until=midpoint))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, list(reversed([str(i) for i in range(150 - limit, 150)])))
# Get a limited number of messages in ascending order from the midpoint up.
limit = 110
midpoint = events[149].domain_event_id
messages = list(reader.get_messages(is_ascending=True, page_size=10, limit=limit, after=midpoint))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(150, 150 + limit)])
# Get a limited number of messages in descending order above the midpoint down.
limit = 200
midpoint = events[150].domain_event_id
messages = list(reader.get_messages(is_ascending=False, page_size=10, limit=limit, after=midpoint))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), 150)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, list(reversed([str(i) for i in range(150, 300)])))
# Get a limited number of messages in ascending order below the midpoint up.
limit = 200
midpoint = events[149].domain_event_id
messages = list(reader.get_messages(is_ascending=True, page_size=10, limit=limit, until=midpoint))
self.assertLess(limit, number_of_messages)
self.assertEqual(len(messages), 150)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(150)])
#
# Use the last position to start part way through.
limit = 20
last_position = reader.position
messages = reader.get_messages(is_ascending=True, page_size=10, limit=limit, after=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(150, 150 + limit)])
# Do it again.
last_position = reader.position
messages = reader.get_messages(is_ascending=True, page_size=10, limit=limit, after=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the same as the created order.
self.assertEqual(messages, [str(i) for i in range(150 + limit, 150 + limit * 2)])
# Go back.
last_position = reader.position
messages = reader.get_messages(is_ascending=False, page_size=10, limit=limit, until=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, [str(i) for i in range(148 + limit * 2, 148 + limit, -1)])
# Go back.
last_position = reader.position
messages = reader.get_messages(is_ascending=False, page_size=10, limit=limit, until=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, [str(i) for i in range(128 + limit * 2, 128 + limit, -1)])
# Go back.
last_position = reader.position
messages = reader.get_messages(is_ascending=False, page_size=10, limit=limit, until=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, [str(i) for i in range(108 + limit * 2, 108 + limit, -1)])
# Repeat.
messages = reader.get_messages(is_ascending=False, page_size=10, limit=limit, until=last_position)
messages = list(messages)
self.assertEqual(len(messages), limit)
# Expect the order of the messages is the reverse of the created order.
self.assertEqual(messages, [str(i) for i in range(108 + limit * 2, 108 + limit, -1)])