It's really nice kata but c'mon - whole description is inconsistent (not even mention that tests are failing and boiler code is wrong). You are saying that there should be no literal hello world but putting it into comment also doesn't work. Probably it uses regex magic internally but it would be better to use some JS parser like Esprima or whatever and parse user source code.

Shouldn't it be somewhere noted that A that is mentioned in description is actually parameter n (at least in JS code it is named n)