angular1 watchers counter userscript

watchers.js

// ==UserScript==
// @name        watchers
// @namespace   *.dev
// @version     1
// @grant       none
// @run-at document-end
// ==/UserScript==

(function(){
  if (!window.hasOwnProperty('angular')) return;
  window.getWatchers = function(root) {
    root = angular.element(root || document.documentElement);
    var watcherCount = 0;

    function getElemWatchers(element) {
      var isolateWatchers = getWatchersFromScope(element.data().$isolateScope);
      var scopeWatchers = getWatchersFromScope(element.data().$scope);
      var watchers = scopeWatchers.concat(isolateWatchers);
      angular.forEach(element.children(), function (childElement) {
        watchers = watchers.concat(getElemWatchers(angular.element(childElement)));
      });
      return watchers;
    }

    function getWatchersFromScope(scope) {
      if (scope) {
        return scope.$$watchers || [];
      } else {
        return [];
      }
    }

    function getWatcherExpressions (element) {
      var watchers = getElemWatchers(element);
      var watchlist = {
        '_total': watchers.length
      };
      angular.forEach(watchers, function (watcher) {
        watchlist[watcher.exp] = watchlist[watcher.exp] || [];
        watchlist[watcher.exp].push(watcher);
      });
      return watchlist;
    }

    return getWatcherExpressions(root);
  }
  var wathcers = 0;
  var showWatchersCount = function() {
    if (wathcers === window.getWatchers()._total) return;
    wathcers = window.getWatchers()._total;    
    console.log('watchers', wathcers);
  }

  document.onreadystatechange = function () {
    
      
      if (document.readyState == "complete") {
          showWatchersCount();
          setInterval(showWatchersCount, 2000);
          
      }
  };
  
}());