There are only two tests in the data section: arrayCombined and arrayWeighted. The arrayCombined is a completely useless test. Most of the operations it does is on an empty array. It has a 10 element, 100 element, and 500 element array. The 500 element array is emptied after 3 iterations. Which means that it runs array.pop and array.shift 499,875 times on an empty array. It also runs array.reverse, array.sort, array.slice, and array.splice on an empty array 9,998 times.

So, while it is interesting that Chrome is extremely fast on empty arrays, I don't see how that is useful in the real world.

If you modified the test so that the three arrays were local to the function, then the test would be useful.