I’m pretty sure this is wrong. JS objects and arrays are different. The former will only yield elements from the array itself when iterated on, and has a consistent iteration order, while the later does not.
Arrays are objects of class Array which have special literals, override the toString() method, and update the non-enumerable "length" property on certain operations.
Try calling Object.keys([1, 2, 3]), or even better try Object.getOwnPropertyNames([1, 2, 3])
