"use strict";

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } }

var addCounter = function addCounter(list) {

  //list.concat([0])
  return [].concat(_toConsumableArray(list), [0]);
};

var removeCounter = function removeCounter(list, idx) {
  return list.slice(0, idx).concat(list.slice(idx + 1));
};

var incrementCounter = function incrementCounter(list, index) {
  return [].concat(_toConsumableArray(list.slice(0, index)), [list[index] + 1], _toConsumableArray(list.slice(index + 1)));
};

var testAddCounter = function testAddCounter() {
  var listBefore = [];
  var listAfter = [0];

  expect(addCounter(listBefore)).to.eql(listAfter);
};

var testRemoveCounter = function testRemoveCounter() {

  var listBefore = [0, 10, 20];
  var listAfter = [0, 20];

  expect(removeCounter(listBefore, 1)).to.eql(listAfter);
};

var testIncrementCounter = function testIncrementCounter() {
  var listBefore = [0, 10, 20];
  var listAfter = [0, 11, 20];

  expect(incrementCounter(listBefore, 1)).to.eql(listAfter);
};

testAddCounter();
testRemoveCounter();
testIncrementCounter();

testAddCounter();

console.log("ALL TEST PASS");