python new test framework is required. updated in this fork

(JS) Description doesn't mention null can be given as an argument, and test expects null in that case.

This is not how CapsLock works. It's specified, but it should not be called CapsLock or it should behave like CapsLock.

Also, the thingy with null is not correct for JavaScript. We are promised a String, we should be given a String. If you want to allow for the possibility of calling the function with fatFingers(), that would be ( more or less ) equivalent to passing undefined, NOT null. I'd also argue that the correct return value would then be "", not undefined again or null. I have never understood the practice of passing null to functions, but in Java it seems to make sense. In JavaScript, it doesn't.