Omg thank you so much for pointing that out :') I got it! It definitely wasn't the best way to do it... I added two more else if's for when n is equal to 1 or 2, but it got the job done. Again thank you!

I am getting: "arrays first differed at element [0]; expected: 1.0 but was: 0.0" for basicTests(XbonacciTest), and "It should work with random inputs too: arrays first differed at element [0]; expected:18.0 but was: 0.0" for randomTests(XbonacciTest)

Nevermind! It's not passing the randomTests after running it again now, with the code unchanged. I've spent too long on this...

I'd like to add that it's passing the randomTests(XbonacciTest) after I took the static keyword out when declaring the method (I had it like that because I was testing by calling the method in a main method working in Eclipse). It's just not passing the basicTests(XbonacciTest) now