I am having same issue. I think it is because, test case #4 is passing "null" in any/both parameters.

Please which language? Print your input and your output in your console so you will be able to see your error.

I getting following error in test 2 and 4:

expected: but was:

I don't understand the error.

I'm having errors for Test #4, can anyone tell me what it is testing?
errors:
System.NullReferenceException : Object reference not set to an instance of an object
at AreTheySame.comp (System.Int32[] a, System.Int32[] b) [0x00000] in :0
at AreTheySameTests.Test4 () [0x00000] in :0