1. Your test procedures aren't named very well. The name of the procedure should tell us what we're testing for. Labeling them as 1,2,3 means we have to look at the test code to figure out which test failed. Make the names clear and meaningful, even if they're abnormally long. That's okay for tests. 
 2. It doesn't look like you've covered all of the possible test cases. It looks like it's possible for your input to have four consecutive slashes, but you don't test that possibility. 

        String[] split = promptName.split("\\\\");