Wow! Thanks! I was bookmarking all of my katas, just so I didn't have to find them again. This removes the need for that. :)

In the description is explained:

/* from: starting square
* movements: quantity of movements to do
* returns: array with all possible valid squares
*
* knightEngine -> Square -> Int -> [Square]
*/
function knightEngine(from, movements) {
}

You can implement this function using compose, bind and moveKnight functions.

Looking for those?

search for kata with the tag ES2015. ES6 works too but there are more results when searching ES2015. Also you will get more results if you look for approved and beta since the ES2015 ones are newer and fewer of them have been approved.

Shameless plug. I have two katas dealing with ES2015 Generator functions

Prime Number Generator :Simple version
Prime Number Generator:Intermeddiate (with inputs) version