We don't need another lame, trival, low quality kata that does the same thing... --> https://www.codewars.com/kata/search/my-languages?q=filter&order_by=sort_date%20desc

I might as well post another wall of filtering based katas that I have collected (not done yet) here later to give some form of insights @glovastefan

Change the "var" in the description to "let".

JS and Coffeescript have no random tests

This is totally not necessary:

It should test for valid values, invalid values and edge cases.

Example scenario:

You are building a web app that records user interactions for analytics. Your app should only be interested in real values. For example, 'cta-clicked' or 'header-clicked' would be acceptable values that you'd want your app to store in an array.

The rest of the description provides plenty of information to solve this Kata. That part I quoted just makes it more confusing and I think it should be removed.