yep, as length of the result string growth every character.

omg xDDD, but i guess if this is the case, then it should be something like 8 kyu?

i guess it's to late but, in reduce, you have initial value after callback function, which is most of the times called accumulator. So if initial value is 0 and there is no elements in an array - it return 0, as callback never called.

The task description is vague. The two-words test should either be included as a basic test or explicitly mentioned in the task description.

Yep, vague task description. Basically a word is space + Capital letter. I though i solved the problem untill saw that fixed test xD