We can do it, because we use :transaction strategy with DatabaseCleaner,
which starts transaction before each test and rollbacks after it. That
way data before each test is consistent.
The big advantage of such approach is that tests are fast now - we need
to only load Scenario data once.
One of the drawbacks, on the other hand, is that we need to always load
this data, even if no integration tests need running.
We can try to be smart about it and check if any integration tests are
loaded.
If there is an error somewhere along the line (like in DB connection
management), it should not interfere with returning proper result for
OPTIONS request. Otherwise it's hard to guess why the actual request in
the browser was not properly sent.