well actually the prompt said crystal clear that were ordered, and even said in which direction and with the extremes included: " Given a list of unique numbers sorted in ascending order, return a new list so that the values increment by 1 for each index from the min to the max value, both included"

Given a list of unique numbers sorted in ascending order, - Unless the description was different at the time of your comment, they did specify it was ascending/unique. Solution works and I did the same. Yes it doesn't work for disordered arrays, but that wasn't the task to complete.

While it works for this kata, it only does so due to limited test cases. The prompt gives no indication that the array can be assumed in order and even asks for an ordered array from "minimum value up to the maximum value". Just something to keep in mind before assuming this solution is the best one.