I like the idea !
Great solution .

As a sugegstion you could preload the houses array so people don't need to copy paste it in the code

This is such a poorly-made kata it should be banished to the netherworld.

The kata was unclear and the houses was not preloaded by default.

Houses should be passed to the function, to avoid access outter scope.

function motto(name ,houses) {

}

very elegant way, but the complexity of this solution is O(n^2) I can't vote for this solution as best practice :)

Nice!

No random tests.

This solution is concise and easy to comprehend.

tests limit solution

Inefficient storage method, and you shouldn't build tests around them using your specific data structure "houses" unless you are going to provide it for them and make it mandatory in the kata description.

the houses array should be provided by default. I was not expecting to have to put the arraay myself. It's misleading.

This is a great one. Love this declarative + es6 way

that's a seriously awesome way of solving this one.. I love it. :)

didn't even think of using findIndex(), but since it already returns either the index or -1, it actually does some of the work for you.