def test_rolls_back_uncommitted_work_by_default(sqlite_session_factory):
uow = unit_of_work.SqlAlchemyUnitOfWork(sqlite_session_factory)
with uow:
insert_batch(uow.session, 'batch1', 'MEDIUM-PLINTH', 100, None)
new_session = sqlite_session_factory()
rows = list(new_session.execute('SELECT * FROM "batches"'))
assert rows == []
def try_to_allocate(orderid, sku, exceptions, session_factory):
line = model.OrderLine(orderid, sku, 10)
try:
with unit_of_work.SqlAlchemyUnitOfWork(session_factory) as uow:
product = uow.products.get(sku=sku)
product.allocate(line)
time.sleep(0.2)
uow.commit()
except Exception as e: # pylint: disable=broad-except
print(traceback.format_exc())
exceptions.append(e)
def test_rolls_back_on_error(sqlite_session_factory):
class MyException(Exception):
pass
uow = unit_of_work.SqlAlchemyUnitOfWork(sqlite_session_factory)
with pytest.raises(MyException):
with uow:
insert_batch(uow.session, 'batch1', 'LARGE-FORK', 100, None)
raise MyException()
new_session = sqlite_session_factory()
rows = list(new_session.execute('SELECT * FROM "batches"'))
assert rows == []
def test_uow_can_retrieve_a_batch_and_allocate_to_it(sqlite_session_factory):
session = sqlite_session_factory()
insert_batch(session, 'batch1', 'HIPSTER-WORKBENCH', 100, None)
session.commit()
uow = unit_of_work.SqlAlchemyUnitOfWork(sqlite_session_factory)
with uow:
product = uow.products.get(sku='HIPSTER-WORKBENCH')
line = model.OrderLine('o1', 'HIPSTER-WORKBENCH', 10)
product.allocate(line)
uow.commit()
batchref = get_allocated_batch_ref(session, 'o1', 'HIPSTER-WORKBENCH')
assert batchref == 'batch1'
def test_concurrent_updates_to_version_are_not_allowed(
postgres_session_factory):
sku, batch = random_sku(), random_batchref()
session = postgres_session_factory()
insert_batch(session, batch, sku, 100, eta=None, product_version=1)
session.commit()
order1, order2 = random_orderid(1), random_orderid(2)
exceptions = [] # type: List[Exception]
try_to_allocate_order1 = lambda: try_to_allocate(order1, sku, exceptions,
postgres_session_factory)
try_to_allocate_order2 = lambda: try_to_allocate(order2, sku, exceptions,
postgres_session_factory)
thread1 = threading.Thread(target=try_to_allocate_order1)
thread2 = threading.Thread(target=try_to_allocate_order2)
thread1.start()
thread2.start()
thread1.join()
thread2.join()
[[version]] = session.execute(
"SELECT version_number FROM products WHERE sku=:sku",
dict(sku=sku),
)
assert version == 2
[exception] = exceptions
assert 'could not serialize access due to concurrent update' in str(
exception)
orders = list(
session.execute(
"SELECT orderid FROM allocations"
" JOIN batches ON allocations.batch_id = batches.id"
" JOIN order_lines ON allocations.orderline_id = order_lines.id"
" WHERE order_lines.sku=:sku",
dict(sku=sku),
))
assert len(orders) == 1
with unit_of_work.SqlAlchemyUnitOfWork(postgres_session_factory) as uow:
uow.session.execute('select 1')