def test_validates_stream_and_crashes_when_invalid(writer, stream, state):
messages = list(islice(transactions(), 3))
messages[1] = messages[0]
writer.push(messages)
with pytest.raises(SequencingError):
list(stream.consume(state))
def test_uses_existing_stream_state_if_it_exists(writer, stream, state):
writer.push(islice(transactions(), 6))
iterator = stream.consume(state)
next(iterator)
next(iterator)
(new_state, offset, message) = next(iterator)
new_iterator = stream.consume(new_state)
(_, new_offset, _) = next(new_iterator)
assert new_offset == 3
def sliced_transaction():
two_transactions = list(islice(transactions(), 6))
head, remainder = two_transactions[0], two_transactions[1:]
assert head.batch_operation.begin_operation == begin
yield remainder
