Good patterns for unit testing form beans that have annotation-based validation in Spring MVC

Question

When using annotation based validation for a form bean, what is the best practice for unit-testing those beans in order to ensure that correct validations annotations are sp

Answer 1

Two things you should consider:

Do Not test your third party libraries/frameworks.

You should rely on them, they are supposed to be already tested by their maintainers and the surrounding community usage. You don't test them, you rather assess them. To make sure that they fit your needs and mitigate the risks.

Testing behavior is what matter, really!

In the vast majority of applications there is little place for real UNIT testing as the business logic is either small are widespread across multiple modules of the application. So you should consider Integration testing with the same priority than Unit testing. And this is more easily captured by using a behavioral approach.

So, to answer your question, you should not try to Unit test a form bean at all. It's just a transport object. What you should test is how the receiver react with that form, and check both the normal case and the edge cases.