feat(ngMock): decorator that adds Scope#$countChildScopes and Scope#$countWatchers

src/ng/rootScope.js

@@ -113,6 +113,10 @@ function $RootScopeProvider() {
          expect(parent.salutation).toEqual('Hello');
      * ```
      *
+     * When interacting with `Scope` in tests, additional helper methods are available on the
+     * instances of `Scope` type. See {@link ngMock.$rootScope.Scope ngMock Scope} for additional
+     * details.
+     *
      *
      * @param {Object.<string, function()>=} providers Map of service factory which need to be
      *                                       provided for the current scope. Defaults to {@link ng}.

src/ngMock/angular-mocks.js

@@ -1823,6 +1823,7 @@ angular.module('ngMock', ['ng']).provider({
   $provide.decorator('$timeout', angular.mock.$TimeoutDecorator);
   $provide.decorator('$$rAF', angular.mock.$RAFDecorator);
   $provide.decorator('$$asyncCallback', angular.mock.$AsyncCallbackDecorator);
+  $provide.decorator('$rootScope', angular.mock.$RootScopeDecorator);
 }]);
 
 /**
@@ -2031,6 +2032,110 @@ angular.mock.e2e.$httpBackendDecorator =
   ['$rootScope', '$delegate', '$browser', createHttpBackendMock];
 
 
+/**
+ * @ngdoc type
+ * @name $rootScope.Scope
+ * @module ngMock
+ * @description
+ * {@link ng.$rootScope.Scope Scope} type decorated with helper methods useful for testing. These
+ * methods are automatically available on any {@link ng.$rootScope.Scope Scope} instance when
+ * `ngMock` module is loaded.
+ *
+ * In addition to all the regular `Scope` methods, the following helper methods are available:
+ */
+angular.mock.$RootScopeDecorator = function($delegate) {
+
+  var $rootScopePrototype = Object.getPrototypeOf($delegate);
+
+  $rootScopePrototype.$countChildScopes = countChildScopes;
+  $rootScopePrototype.$countWatchers = countWatchers;
+
+  // TODO: remove if Object.getPrototypeOF works on IE9
+  //var originalScopeNew = $delegate.$new;
+  //$delegate.$new = decoratedScopeNew;
+
+  return $delegate;
+
+  // ------------------------------------------------------------------------------------------ //
+
+  /**
+   * @ngdoc method
+   * @name $rootScope
+   * @module ngMock
+   * @description
+   * Counts all the direct and indirect child scopes of the current scope.
+   *
+   * The current scope is excluded from the count. The count includes all isolate child scopes.
+   *
+   * @returns {number} Total number of child scopes.
+   */
+  function countChildScopes() {
+    var count = 0; // exclude the current scope
+    var pendingChildHeads = [this.$$childHead];
+    var currentScope;
+
+    while (pendingChildHeads.length) {
+      currentScope = pendingChildHeads.shift();
+
+      while (currentScope) {
+        count += 1;
+        pendingChildHeads.push(currentScope.$$childHead);
+        currentScope = currentScope.$$nextSibling;
+      }
+    }
+
+    return count;
+  }
+
+
+  /**
+   * @ngdoc method
+   * @name $rootScope
+   * @module ngMock
+   * @description
+   * Counts all the watchers of direct and indirect child scopes of the current scope.
+   *
+   * The watchers of the current scope are included in the count and so are all the watchers of
+   * isolate child scopes.
+   *
+   * @returns {number} Total number of watchers.
+   */
+  function countWatchers() {
+    var count = this.$$watchers ? this.$$watchers.length : 0; // include the current scope
+    var pendingChildHeads = [this.$$childHead];
+    var currentScope;
+
+    while (pendingChildHeads.length) {
+      currentScope = pendingChildHeads.shift();
+
+      while (currentScope) {
+        count += currentScope.$$watchers ? currentScope.$$watchers.length : 0;
+        pendingChildHeads.push(currentScope.$$childHead);
+        currentScope = currentScope.$$nextSibling;
+      }
+    }
+
+    return count;
+  }
+
+
+  // TODO: remove if Object.getPrototypeOF works on IE9
+  ///**
+  // * preserves monkey patched methods on isolate scopes (which don't inherit from $rootScope)
+  // * */
+  //function decoratedScopeNew(isolate) {
+  //  var newScope = originalScopeNew.apply(this, arguments);
+  //
+  //  if (isolate) {
+  //    newScope.$countChildScopes = countChildScopes;
+  //    newScope.$countWatchers = countWatchers;
+  //  }
+  //
+  //  return newScope;
+  //}
+};
+
+
 if (window.jasmine || window.mocha) {
 
   var currentSpec = null,

test/ngMock/angular-mocksSpec.js

@@ -1507,6 +1507,174 @@ describe('ngMock', function() {
       expect($rootElement.text()).toEqual('');
     }));
   });
+
+
+  ddescribe('$rootScopeDecorator', function() {
+
+    describe('$countChildScopes', function() {
+
+      it('should return 0 when no child scopes', inject(function($rootScope) {
+        expect($rootScope.$countChildScopes()).toBe(0);
+
+        var childScope = $rootScope.$new();
+        expect($rootScope.$countChildScopes()).toBe(1);
+        expect(childScope.$countChildScopes()).toBe(0);
+
+        var grandChildScope = childScope.$new();
+        expect(childScope.$countChildScopes()).toBe(1);
+        expect(grandChildScope.$countChildScopes()).toBe(0);
+      }));
+
+
+      it('should correctly navigate complex scope tree', inject(function($rootScope) {
+        var child;
+
+        $rootScope.$new();
+        $rootScope.$new().$new().$new();
+        child = $rootScope.$new().$new();
+        child.$new();
+        child.$new();
+        child.$new().$new().$new();
+
+        expect($rootScope.$countChildScopes()).toBe(11);
+      }));
+
+
+      it('should provide the current count even after child destructions', inject(function($rootScope) {
+        expect($rootScope.$countChildScopes()).toBe(0);
+
+        var childScope1 = $rootScope.$new();
+        expect($rootScope.$countChildScopes()).toBe(1);
+
+        var childScope2 = $rootScope.$new();
+        expect($rootScope.$countChildScopes()).toBe(2);
+
+        childScope1.$destroy();
+        expect($rootScope.$countChildScopes()).toBe(1);
+
+        childScope2.$destroy();
+        expect($rootScope.$countChildScopes()).toBe(0);
+      }));
+
+
+      it('should work with isolate scopes', inject(function($rootScope) {
+        /*
+                  RS
+                  |
+                 CIS
+                /   \
+              GCS   GCIS
+         */
+
+        var childIsolateScope = $rootScope.$new(true);
+        expect($rootScope.$countChildScopes()).toBe(1);
+
+        var grandChildScope = childIsolateScope.$new();
+        expect($rootScope.$countChildScopes()).toBe(2);
+        expect(childIsolateScope.$countChildScopes()).toBe(1);
+
+        var grandChildIsolateScope = childIsolateScope.$new(true);
+        expect($rootScope.$countChildScopes()).toBe(3);
+        expect(childIsolateScope.$countChildScopes()).toBe(2);
+
+        childIsolateScope.$destroy();
+        expect($rootScope.$countChildScopes()).toBe(0);
+      }));
+    });
+
+
+    describe('$countWatchers', function() {
+
+      it('should return the sum of watchers for the current scope and all of its children', inject(
+        function($rootScope) {
+
+          expect($rootScope.$countWatchers()).toBe(0);
+
+          var childScope = $rootScope.$new();
+          expect($rootScope.$countWatchers()).toBe(0);
+
+          childScope.$watch('foo');
+          expect($rootScope.$countWatchers()).toBe(1);
+          expect(childScope.$countWatchers()).toBe(1);
+
+          $rootScope.$watch('bar');
+          childScope.$watch('baz');
+          expect($rootScope.$countWatchers()).toBe(3);
+          expect(childScope.$countWatchers()).toBe(2);
+      }));
+
+
+      it('should correctly navigate complex scope tree', inject(function($rootScope) {
+        var child;
+
+        $rootScope.$watch('foo1');
+
+        $rootScope.$new();
+        $rootScope.$new().$new().$new();
+
+        child = $rootScope.$new().$new();
+        child.$watch('foo2');
+        child.$new();
+        child.$new();
+        child = child.$new().$new().$new();
+        child.$watch('foo3');
+        child.$watch('foo4');
+
+        expect($rootScope.$countWatchers()).toBe(4);
+      }));
+
+
+      it('should provide the current count even after child destruction and watch deregistration',
+          inject(function($rootScope) {
+
+        var deregisterWatch1 = $rootScope.$watch('exp1');
+
+        var childScope = $rootScope.$new();
+        childScope.$watch('exp2');
+
+        expect($rootScope.$countWatchers()).toBe(2);
+
+        childScope.$destroy();
+        expect($rootScope.$countWatchers()).toBe(1);
+
+        deregisterWatch1();
+        expect($rootScope.$countWatchers()).toBe(0);
+      }));
+
+
+      it('should work with isolate scopes', inject(function($rootScope) {
+        /*
+                 RS=1
+                   |
+                CIS=1
+                /    \
+            GCS=1  GCIS=1
+         */
+
+        $rootScope.$watch('exp1');
+        expect($rootScope.$countWatchers()).toBe(1);
+
+        var childIsolateScope = $rootScope.$new(true);
+        childIsolateScope.$watch('exp2');
+        expect($rootScope.$countWatchers()).toBe(2);
+        expect(childIsolateScope.$countWatchers()).toBe(1);
+
+        var grandChildScope = childIsolateScope.$new();
+        grandChildScope.$watch('exp3');
+
+        var grandChildIsolateScope = childIsolateScope.$new(true);
+        grandChildIsolateScope.$watch('exp4');
+
+        expect($rootScope.$countWatchers()).toBe(4);
+        expect(childIsolateScope.$countWatchers()).toBe(3);
+        expect(grandChildScope.$countWatchers()).toBe(1);
+        expect(grandChildIsolateScope.$countWatchers()).toBe(1);
+
+        childIsolateScope.$destroy();
+        expect($rootScope.$countWatchers()).toBe(1);
+      }));
+    });
+  });
 });