Will the 'finally' block fire even after a Junit test throws an Assertion Error from with in 'try' block?

Yes, the finally block will run. Junit assertion errors are just normal exceptions so the usual java try-catch-finally pattern will work. You can even catch the AssertionError exception if you wanted.

Yes. Finally blocks are meant to be a container for code that fire no matter what. JUnit, or this example, is no different.