While playing around with Java 8 Optionals and validation I've encountered some cases I think the validation does not behave as intended.
It might be that this is related to the somewhat special meaning of an Optional, but the problem relies in such cases when I want to validate the container (the Optional) separate from the actual value. I've tried to use the new type annotations to do so.
So without further ado I redirect you to my branch containing the test cases showing what I think is not intended behavior. I've added a JavaDoc for the failing test cases.
If you want I can add a textual description for the failing test cases in this ticket, too.