mrdavidlaing’s functional-koans at javascript – GitHub
When you first run the koans, you’ll be presented with a runtime error and a stack trace indicating where the error occurred. Your goal is to make the error go away. As you fix each error, you should learn something about the Javascript language and functional programming in general.
Your journey towards Javascript enlightenment starts in the koans/AboutExpects.js file. These koans will be very simple, so don’t overthink them! As you progress through more koans, more and more Javascript syntax will be introduced which will allow you to solve more complicated problems and use more advanced techniques.