This kata needs to be updated to a newer version of Node, but it seems to rely on some specific setup of Node 8 or Codewars runner for Node 8. Any help with modifying it so it works with Node 14 is appreciated.

The "solution" is based on "implementation-defined" Array.prototype.sort behaviour. Check ecma-262 if you don't believe me, especially the part which defines "consistent comparison function". It's wrong on semantic level and basically useless as part of any training.

The tests... don't test much.

This is probably not the type of problem that would be suitable for a platform like CW.