[Maxmaxmaximus4]

Твоя функция не справилась с этим

var oldArray = [1, 2, 3, 4, 5, 6, 7, 8, 9];
var newArray = [1, 2, 3, 5, 34, 32, 4, 45];
var changes = compare(oldArray, newArray);

console.log(changes);

function compare(oArr, arr) {
    var search = arr.slice();
    var insert = [];
    var remove = [];

    for (var i = 0, index; i < oArr.length; i++) {
      index = search.indexOf(oArr[i]);
      if (index < 0) remove.push(i);
      else delete search[index];
    }

    for (var i = 0; i < search.length; i++) {
      if (i in search) insert.push(i);
    }

    return {
      remove: remove,
      insert: insert
    }
}