JS: Node v12 should be used enabled along with its appropiate assertion tools (Mocha + Chai).

Not an issue.

Thanks, for pointing this out. Typo.

It's tagged mudolo; I think you meant modulo.
The sample test case uses expect which returns tests for a boolean, which should pass most things (I'm not sure if this is a conscious design choice, forcing the user to look up and make their own tests).
Otherwise, a good kata, and should be brought out of beta

CoffeeScript translation published.

I've attempted to update the description a bit, do you mind reading it and letting me knwo what you think? Please read the entire description including the code expamles and comments in the code examples.

This needs a better description. Specifically, a list of the rules for when the function "knows" the response, and when it should pretend not to know.

Your test cases make it fairly clear. I would consider adding something like these to your description:

• "should return fn's expected return value if < 3 calls or odd call"
• "should return 'hmm, I don't know!' if even and greater than 3"