If both strings have the same length, both your vars shorterString and longerString are s2. So your code ignores s1 content and you think s1 and s2 are equal. Always when debugging print the input values as they were (without any processing from you), it'll help you next time.

Random tests strings (because there is no fixed test with that input) are randomly generated, and it would be very very rare both string were exactly the same. I've checked the control function and if the strings were those, the expected output would be 'ghjlqrtuvxz'. Try posting your code marking your post as having spoiler content.

Javascript, thanks for the heads up.

When reporting a problem, state the language (more if the kata has several like this one) so it can be checked.

When submitting my attempt, I am tested on the same string for s1 and s2, "jjvvvrrqqqqhhhhlxxxxhhggggguuzurrvvvtt". Somehow, it tells me that the expected output for all the uniqure characters in this string (s1 and s2 BOTH equal this string) is "ghjklpqrtuvwxyz". There is absolutely no k in this string, or a p, or w, etc.

I am also hit with 13 other errors of the same nature - how is this possible? Is there anyway this can be checked, because I know my solution is right, I pass 95%, but with these answers, it is obvious that the expected result is incorrect.

I also have screenshots saved locally