It wasn't, but it is now.

Seems to be fixed

After looking at the test cases, just put this on each test:

sort (splitInteger Some Value) `shouldBe` [Lah, Dee, Dah]

This should clear up people's problems! You will have to import Data.List, additionally.

Ah! I didn't write those, I still haven't gotten use to that feature. We'll all need to specify which language you are testing in the future.

This might be a good addition to the platform (automatically tagging the language when commenting). I'll suggest it.

Haskell tests don't sort anything.

I'm not sure what you are referring to. All my tests use the same method for testing, and the both the expected and actual solution is always sorted before testing.

Are you sure your solution is correct?

The instruction said [4,4, 3,3..] and that the order doesn't matter, your test check for [3,3,...,4,4] without sorting beforehand...

Given that 0 is a natural number, just saying that it's defined for them would be enough.

A "power set" of a set E is P(E), that is the set of all subsets (part) of E. Why is it called "power set" ? Because you can see it as the set of all functions from E to the boolean set (if True is associated to an element, it is in the subset) which would be noted B^E (if B is the boolean set) and thus has 2^(Card E) elements.

Of course the interpretation with lists/arrays is to handle those as sets, so you have to forget the ordering of the elements.