One trick I've used in Scala code is to put the test suite in the same package as the code under test, which gives the tests access to package-private stuff whi

One trick I've used in Scala code is to put the test suite in the same package as the code under test, which gives the tests access to package-private stuff which are normally inaccessible to other code. That probably could work for Java as well. (And in C++, I guess you could declare the test suite as a "friend" of the code under test --- "C++, the language in which friends can access your private members!".) I feel a bit funny about this, though; it does make the tests explicitly dependent on stuff that, to the rest of the code, is a hidden implementation detail. So, it's probably better to test only the public interface wherever that's feasible...