Javascript 'Promises' exercise testing problems

There is something if not bugged at least not ideal with the 'Promises' excercise in the javascript track, I had the first function written in a way I was sure was correct but it kept crashing when I ran the tests despite the rest of the functions being 'throw new Error('Remove this statement and implement this function');'. But when I found someone else's code and copied their solution for the rest of the functions (keeping my implementation of the first function 'promisify') it worked perfectly fine.

With some more testing it seems that if the 'promisify' function (the first function in the exercise) is correctly implemented but the 'any' function (which is the last function) isn't implemented the tests will always crash which makes testing your solutions to the different parts of the exercise rather frustrating.