Nodejs Utililty Methods Array Heap Sort

;"use strict";
var log=function(msg){console.log(msg);};
var alert=function(msg){log(msg);};
var arr = [3,6,7,5,3,6,2,9,1,5,33,-12,0,-122,-Infinity, 125, 33, 55, 77];
Array.prototype.heapSort = function () {
  arr = this;
  function _chunk(list) {
    var chunks = [];  
    for(var i=0; i<list.length; i++) {
...

Array.prototype.heapSort = function() {
  if (this.length < 2) {
    return this;
  } else {
    this.heapify();
    this.unheapify();
    return this;

Array.prototype.heapSort = function() {
  var unsortedArray = this;
  class BinaryHeap {
    constructor() {
      this.content = [];
    push(elementToAdd) {
      this.content.push(elementToAdd);
      this.bubbleUp(this.content.length - 1);
...