Finally, what about output?

You shouldn't care about any additional output if a test succeeds, only if it fails.

The JUnit code reports whether each test method succeeds or fails.

If a test method succeeds, JUnit doesn't report anything else about the method.

If a test method fails, it gives the statement that failed - typically an assertEquals call.

In the case of this kind of failure, JUnit also reports the expected value and conflicting expression value.

JUnit gives a backtrace to your class under test, so you can usually see which of your class methods led to the failure.

After that, you have to figure out how to fix the problem.