How to test a directive's controller using angularJS-karma-jasmine?

Question

Goal:

Write a passing test for the waCarousel directive scope variable: self.awesomeThings. Expect this test pass when self.awsomeThings.length.toBe(3) to is true?

Question:

How can I properly write this test? rather how do I inject a directives controller?

---

Directive:

angular.module('carouselApp')
    .directive('waCarousel', function() {
        return {
            templateUrl: '../../../views/carousel/wa.carousel.html',
            controller: function($scope) {
                var self = this;

                self.awesomeThings = [1, 2, 3];

                return $scope.carousel = self;
            }
        }
    });

Unit Test:

describe('waCarousel Unit', function() {
  // am I missing a $controller & namespace variable init?
   var $compile,
      $rootScope;


  // Load the myApp module, which contains the directive
  beforeEach(module('carouselApp'));

  // Store references to $rootScope and $compile and $controller
  // so they are available to all tests in this describe block
  beforeEach(inject(function(_$compile_, _$rootScope_, _$controller_){
    // The injector unwraps the underscores (_) from around the parameter names when matching
    $compile = _$compile_;
    $rootScope = _$rootScope_;
    $controller = _$controller_;
     //   WaCarouselCtrl = $controller('WaCarouselCtrl', {
     //       $scope: scope
     //   });
  }));

  it('should have a list of awesomeThings', function() {
    // This wont pass       
    expect(scope.awesomeThings.length).toBe(3);
  });
});

This is how I would do it for a typical view and not directive:

describe('Controller: MainCtrl', function() {

    // load the controller's module
    beforeEach(module('carouselApp'));

    var MainCtrl,
        scope;

    // Initialize the controller and a mock scope
    beforeEach(inject(function($controller, $rootScope) {
        scope = $rootScope.$new();
        // !!*** this is how I would inject the typical controller of a view **!! //
        MainCtrl = $controller('MainCtrl', {
            $scope: scope
        });
    }));

    it('should attach a list of awesomeThings to the scope', function() {
        expect(scope.awesomeThings.length).toBe(3);
    });
});

How do I merge these two concepts so that I can expect self.awesomeThings.length).toBe(3)?

UPDATE:

Answer 1

Compile the element, and after calling $digest(), you will have access to the scope which contains carousel object with awesomeThings array:

describe('waCarousel Unit', function() {
    var scope;

    beforeEach(module('carouselApp'));
    beforeEach(inject(function($rootScope, $compile) {
        var element = '<test></test>';

        scope = $rootScope.$new();

        element = $compile(element)(scope);
        scope.$digest();
    }));

    it('should have a list of awesomeThings', function() {    
        expect(scope.carousel.awesomeThings.length).toBe(3);
    });
});

Also, here are some useful links to testing directives in angular:

• Testing Directives
• Testing AngularJS directive controllers with Jasmine and Karma
• Introduction to Unit Test: Directives