Angular - Get number of watchers

angular-number-of-watchers.js

var getWatchers = function (element) {
  // convert to a jqLite/jQuery element
  // angular.element is idempotent
  var el = angular.element(
      // defaults to the body element
      element || document.getElementsByTagName('body')
    )
    // extract the DOM element data
    , elData = el.data()
    // initalize returned watchers array
    , watchers = [];

  // AngularJS lists watches in 3 categories
  // each contains an independent watch list
  angular.forEach([
      // general inherited scope
      elData.$scope,
      // isolate scope attached to templated directive
      elData.$isolateScope,
      // isolate scope attached to templateless directive
      elData.$isolateScopeNoTemplate
    ],
    function (scope) {
      // each element may not have a scope class attached
      if (scope) {
        // attach the watch list
        watchers = watchers.concat(scope.$$watchers || []);
      }
    }
  );

  // recurse through DOM tree
  angular.forEach(el.children(), function (childEl) {
    watchers = watchers.concat(getWatchers(childEl));
  });

  return watchers;
};