OP solved it, closing

Yup, i added a note now. Thank you!

Ah. Well, might want to add something in the description about all characters will be unique just so you don't get more comments like this. Great kata, btw.

This solution is actually supposed to pass. Strings in tests contain only unique characters from a to z, and many of people's solutions actually rely on this. They won't pass anymore if I change the tests.

Your code doesn't work. Try putting some console.log statements in there to find your problem. I'd put console.log(x, y, sorting) right above your return statement.

Hint: the value of the integer has nothing to do with the times it appears in the array.

Protip: if you spend more than 30 mins trying to solve a kata (especially if the satisfaction rating is below 90%), read the discourse. I solved this quickly because I looked at it!

Any (real) number squared is a positive number. 14^2 === -14^2.

JavaScript

I was hacking away with some lame regex and fell upon a partial solution that sometimes passes.

Adding this test will prevent similar solutions from passing:

Test.assertEquals( validPass('5k5z963') , 'INVALID' );

uncertain about other languages

There is no test case in which the non-alphanumeric character is in the beginning or the middle.

Just figured out how to do that. Glad I ran into this problem! Thanks.

Not an issue. Don't return the results of the previous tests together with the result of the current test.