I got the solution, however, I do think they should do a better job of clarifing their basic tests.

I'm not calculating the true factorials though. It is passing all the tests. For the case of n=100000, it is returning the correct number of trailing zero in less than 70ms. That was the longest test that ran. Where n<100000, the time it took to return was much faster.

That's for only one test case, this kata is testing for 100+ test cases, random ones included. By the way,

Hint: You're not meant to calculate the factorial. Find another way to find the number of zeros.

I made a soultion and I'm getting an excution time 12000ms out for some reason. When I set a console.time(), the function run less than 70ms for n = 100000.