This Refactoring Kata was designed by Jon Jagger and is available in his Cyber-Dojo. See his blog post
@emilybache have changed it a little, so that the rules more closely match the original game.
If you like this Kata, you may be interested in @emilybache books and website SammanCoaching.org
The problem that this code is designed to solve is explained here: Yatzy
See Cloning a repository for details on how to create a local copy of this project on your computer.
The master branch has the starting code.
The refactor branch has my attempt of refactoring the Kotlin code.