very nice!

Okay, my bad, thank you for your reply. :)

In the task description:

"Implement a function, which takes a non-negative integer"

So non-negative is assumed already. In production code this obviously would want some additional robustness, but based on the description of the task the solution fits.

The tests pass, and those are the final say anyway.

Werent we supossed to check if there is a negative number? Because I can't see it in this code¨.

Well, that was painful... Learned a lot about bitwise operations in JavaScript though, so thanks for that.

As said before, test cases should be added so that failing tests are not misleading anymore.

I had some issue with 'whitespaces' removal as well, but this is maybe more a problem with my coding rather than a kata issue.

Anyway, that's a great kata!