Right but 'so far' for such a hazing interview setup doesn't say much. You handed the candidate your laptop and a bug they don't know from Adam (is it some tricky shadowed var thing? Weird truthiness thing? It's a dumb typo! But only you know that) and are hovering over their shoulder and harumphing when they start typing 'console.'. Or you tell them they're doing it wrong if they start checking something only you already know is not the problem. This all measures something but it's probably not 'problem solving ability' of the sort that's useful for a web front end programmer.