Unit testing AngularJS controller which makes a service call from the ng-submit directive

I am getting started with unit testing a new AngularJs application with Karma, Jasmine and Sinon.

I have a very basic controller, service and template.

The service makes a call to the our service layer which gets some data from the Twitter API:

// Data Service factory
angular
    .module('ttn')
    .factory('dataservice', dataservice);

dataservice.$inject = ['$http'];

function dataservice ($http){
    return {
        getCuratedList: getCuratedList
    };

    function getCuratedList(params){
        return $http.post('/ttn-server/twitter/curatedList', {
            screenName: params.screenName
        }).then(getCuratedListSuccess).catch(getCuratedListFail);

        function getCuratedListSuccess(response){
            return response.data;
        }

        function getCuratedListFail(error){
            return console.log(error);
        }
    }

}

The controller is very thin:

angular.module('ttn').controller('TwitterList', TwitterList);

TwitterList.$inject = ['dataservice', 'results'];

function TwitterList(dataservice, results){

    var vm = this;

    vm.screenName = '';
    vm.results = results;
    vm.submit = submit;

    function submit(event){
        event.preventDefault();
        return dataservice.getCuratedList({
            screenName: vm.screenName
        }).then(function (data) {
            vm.results = data;
        }).catch(function (error) {
            console.warn(error);
        });
    }

}

As is the template HTML:

<h2>Twitter Curated List</h2>

<form ng-submit="vm.submit($event)">
    <p>
        <label for="listSearch">Get lists by screen name:</label>
        <input type="text" id="listSearch" ng-model="vm.screenName"/>
        <input type="submit" id="submit" value="Search" />
    </p>
</form>

<img src="{{vm.results.user.profileImage}}" alt=""/>
<p>Curated by: {{vm.results.user.screenName}}</p>
<p>List Name: <strong>{{vm.results.user.listName}}</strong></p>
<p>Number of members: {{vm.results.user.listMemberCount}}</p>

<ul>
    <li ng-repeat="member in vm.results.members">
        <img src="{{member.profileImage}}" alt=""/>
        <p>@{{member.screenName}}</p>
        <p>{{member.description}}</p>
    </li>
</ul>

I have written some tests which seem good and valid except the final one where i want to test that calling the controller submit function also calls the ttnDataservice.getCuratedList method but I am not sure how to do this.

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

    var controller,
        ttnDataservice,
        stub = sinon.stub();

        stub.withArgs('FooBar').returns([{}, {}, {}, {}]);

    beforeEach(module('ttn'));

    beforeEach((function () {
        var mocks = angular.module('ttnMocks', []);
        mocks.factory('dataservice', function () {
            return {
                getCuratedList: stub
            };
        });
        module('ttnMocks');
    }));

    beforeEach(inject(function ($controller, dataservice) {
        controller = $controller('TwitterList', {
            results: [{}, {}, {}]
        });
        ttnDataservice = dataservice;
    }));

    it('should be the Twitter list controller', function () {
        expect(controller).toBeDefined();
    });

    it('should instantiate the screen name to an empty string', function () {
        expect(controller.screenName).toEqual('');
    });

    it('should instantiate with the results array', function(){
       expect(controller.results).toEqual([{},{},{}]);
    });

    it('should instantiate with a submit function', function () {
        expect(controller.submit).toBeDefined();
    });

    it('should inject the data service layer', function(){
        expect(ttnDataservice).toBeDefined();
    });

    it('should have the getCuratedList method', function(){
        expect(ttnDataservice.getCuratedList).toBeDefined();
    });

    it('should call the getCuratedList service', function(){
        ttnDataservice.getCuratedList();
        expect(ttnDataservice.getCuratedList.called).toBe(true);
    });

    it('should call the getCuratedList service with a Twitter screen name', function(){
        ttnDataservice.getCuratedList('FooBar');
        expect(ttnDataservice.getCuratedList.calledWith('FooBar')).toBe(true);
    });

    it('should call the getCuratedList service with a Twitter screen name and return an array of objects', function(){
        var result = ttnDataservice.getCuratedList('FooBar');
        expect(result).toEqual([{}, {}, {}, {}]);
    });

    it('should call the getCuratedList service from the form submission', function(){
        var event = {preventDefault: jasmine.createSpy()};
        controller.submit(event);
        expect(ttnDataservice.getCuratedList.called).toBe(true);
    });

});