This is a horrible, unexplained and idiotic check (marking this as spoiler would be cruel):

Test.assertEquals(solutionCode.toString().match(/\d+/g).length > 10, false, 'No hardcoding');

Very bad kata. negative numbers are not prime.

not a valid suggestion!

Emotional Damage!!!

Cool kata, had to do something functional :)

Fixed

Fixed

Fixed

Anti-cheat issue - it's banning more stuff than said for and while.

Also, anti-cheat messages should follow standard English grammar + spelling.

Why u r using restricted stuff - Expected: false, instead got: ['if ', 'if ', 'if ']. I am not using while or for, just recursion.

Nope. You are allowed to use String.prototype.length, and people would just use array["len"+"gth"], leading to a war of attrition that can't be won.

Because it is quite impossible to disable [].length, and because filtering for "length" is an iffy proposition at best,
THIS KATA WORKS ON THE HONOUR SYSTEM.

If you want free points, you can have 'em. Note I wrote this kata in a Christmas break ( in an hour ). :D

@JohanWiltnik uh... you didn't check for the keyword length??? :P

Yes I've had this issue too. I haven't used any for or while loops, only if and else if statements and all the tests have passed, apart from the one error message saying that I've used restricted stuff. So what else is restricted besides for and while loops? It's not clear from the instructions.

That is really common, I would estimate, there are 100+ (likely many more) katas which have very poor anti-cheats. They are the hardest to write because there are some very creative coders here.

Without code, this issue is impossible to resolve ... .