old_contents: describe('Testing index controller', function () {
      var controller, scope;
  
      beforeEach(function () {
          // load the module
          module('app');
  
          inject(function($controller, $rootScope){
              scope = $rootScope.$new();
  
              controller = $controller('IndexCtrl', {
                  $scope: scope
              });
          });
  
      });
  
      it('should define the index controller', function() {
          expect(controller).toBeDefined();
      });
  
      it('should define default source as adminMongo', function(){
          expect(scope.source).toBeDefined();
          expect(scope.source).toEqual('/adminMongo');
      })
  
      it('should define the number of tabs (6) on the web page', function(){
          expect(scope.tabs).toBeDefined();
          expect(scope.tabs.length).toEqual(6);
      })
  
      it('should define the function changeSource()', function(){
          expect(scope.changeSource).toBeDefined();
      })
  
      it('should update scope source variable when changeSource() is called', function(){
          scope.changeSource('/sources');
          expect(scope.source).toEqual('/sources');
          expect(scope.source).not.toEqual('/adminMongo');
      })
  
  });
  
new_contents: describe('Testing index controller', function () {
      var controller, scope;
  
      beforeEach(function () {
          // load the module
          module('app');
  
          inject(function($controller, $rootScope){
              scope = $rootScope.$new();
  
              controller = $controller('IndexCtrl', {
                  $scope: scope
              });
          });
  
      });
  
      it('should define the index controller', function() {
          expect(controller).toBeDefined();
      });
  
      it('should define default source as sources', function(){
          expect(scope.source).toBeDefined();
          expect(scope.source).toEqual('/sources');
      })
  
      it('should define the number of tabs (5) on the web page', function(){
          expect(scope.tabs).toBeDefined();
          expect(scope.tabs.length).toEqual(5);
      })
  
      it('should define the function changeSource()', function(){
          expect(scope.changeSource).toBeDefined();
      })
  
      it('should update scope source variable when changeSource() is called', function(){
          scope.changeSource('/sources');
          expect(scope.source).toEqual('/sources');
          expect(scope.source).not.toEqual('/adminMongo');
      })
  
  });
  
subject: update test cases to reduce number of tabs