How to test my http request in my app

I am trying to write units test for my app and I have the following issue

In my controller, I have something like

 $scope.test1 = function() {
     productFactory.getName()
         .then(function(products){
             $scope.result = products;
          })
} 

productFactory

angular.module('myApp').factory('productFactory', function($http) {
    var factoryObj = {};
    factoryObj.getName = function() {
        return http.get(url)
    }

    return factoryObj
})

In my unit test file

describe('test here', function () {
    var testCtrl, scope, httpBackend, mockFactory;

    beforeEach(module('myApp', function($provide){
        $provide.value('productFactory', mockFactory);
    }));

    // Initialize the controller and a mock scope
    beforeEach(inject(function (_$controller_, _$rootScope_, _$httpBackend_,  _productFactory_) {
        scope = _$rootScope_.$new();
        httpBackend = _$httpBackend_;
        mockFactory = _productFactory_;

        testCtrl = _$controller_('testCtrl', {
            $scope: scope
        });

    it('should get product name', function() {       
        scope.test1();
        //I am not sure how to test the results
    });
}));

When I run karma test, it gives me

TypeError: 'undefined' is not an object (evaluating 'productFactory.getName()')

I am not sure how to test the http result and fix the error. Can anyone help me about it? Thanks a lot!