Write tests. Fixes angular#13951

Author: Vadorequest

test/ng/controllerSpec.js

@@ -57,6 +57,27 @@ describe('$controller', function() {
       expect(ctrl instanceof BarCtrl).toBe(true);
     });
 
+    it('should return true when having an existing controller', function() {
+      var FooCtrl = function($scope) { $scope.foo = 'foo'; },
+          scope = {},
+          ctrl;
+
+      $controllerProvider.register({FooCtrl: FooCtrl});
+
+      ctrl = $controller('FooCtrl', {$scope: scope});
+      expect(ctrl.has('FooCtrl')).toBe(true);
+    });
+
+    it('should return false when not having a non existing controller', function() {
+      var FooCtrl = function($scope) { $scope.foo = 'foo'; },
+          scope = {},
+          ctrl;
+
+      $controllerProvider.register({FooCtrl: FooCtrl});
+
+      ctrl = $controller('FooCtrl', {$scope: scope});
+      expect(ctrl.has('whatever')).toBe(false);
+    });
 
     it('should allow registration of controllers annotated with arrays', function() {
       var FooCtrl = function($scope) { $scope.foo = 'bar'; },