AngularJs directive link function testing with jasmine

I'm trying to understand how the directives works and how to test the directives with jasmine. I cant test link function in directive. What I am doing wrong?

  it('should add class', function(){
            //digest the $rootScope
            $scope.$digest();
                expect(element.hasClass('test')).toBe(true);
            });
    });

I am trying to write a test that ensures that the element has an added class. http://ift.tt/1S2m4pl

I'm receiving error element.addClass it not a function.