I think I didn't understand what I had to do in this Kata because if this is the solution you're only checking the next and guesses the answer but it doesn't really check if that was the best or correct answer.

In the example:

[10, 5, 2, 3, 7, 5], 10

If I move the last five one step back the result is [5,5].

But the real answer is still [3,7] because the difference in proximinity is (5 - 4) = 1 vs (5 - 1) = 4.

Not convinced by this answer at all it just hacks the tester.

I cannot get the values in JS for some reason, so I don't understand exactly what I have to do :S

Example button in Python just throw a error. But the other button works well.

You're right, I was doesn't understanding how to use the buttons.

My bad.

The test doesn't work.