do tests save anything in the test db?

I have some validation tests that create!() Users, but after running the
tests I don't see anything in my test db. What is supposed to happen?

Yes. By default, the Rails test framework is configured to run each
test method in a transaction which gets rolled back at the end of that
test method. That way each test method is isolated from data that
might otherwise be left lying around.

HTH,
David