how to mock the backend for angularjs app?

angularjs, angularjs-factory, unit-testing

Solution

Here is a working test for the factory as you posted it. I added a variable $httpBackend for the injected httpBackend. And a call to $httpBackend.flush(). fiddle-demo (read to the end for full description of fiddle content)

describe( 'Global Service: ', function() {
    var Global, $httpBackend

    // load the relevant application module, with the service to be tested
    beforeEach( module('bkJoga') );

    beforeEach( function() {

        // inject the mock for the http backend
        inject(function(_$httpBackend_) {
            $httpBackend = _$httpBackend_;
        });
        // mock the response to a particular get request
        $httpBackend.whenGET('/jogasok').respond([
            {id: 1, name: 'asdfasdf'}, 
            {id: 2, name: '2wrerwert'}
        ]);
        // inject the service to be tested
        inject(function(_Global_) {
            Global = _Global_;
        });
    });

    it('should exist', function() {
        expect(!!Global).toBe(true);
    });

    it('getJogasok should return everyone', function() {
        $httpBackend.flush();    // <------------ need to flush $httpBackend
        expect(JSON.stringify(Global.getJogasok())).toBe(JSON.stringify([
            {id: 1, name: 'asdfasdf'}, 
            {id: 2, name: '2wrerwert'}
        ]));
    });
});

In any event, I would rewrite the factory a bit differently, because, as it is currently written, it queries the database only upon instantiation `var jogasok = Jogas.query();`. Because services in angularjs are singletons, in your app you will have only the data as they are at the time of instantiation. Therefore, later modifications to the data will not be reflected in your factory. Here is an example of the factory and its unit-test that reflects this idea.

the factory:

app.factory('GlobalBest', function ($resource) {
    return $resource('/jogasok/:id', {
        'id': '@id'
    }, {
        'ujBerlet': {
            'method': 'POST',
                'params': {
                'berlet': true
            }
       }
    });
});

the test:

describe('GlobalBest Service: ', function () {
    var srv, $httpBackend;

    beforeEach(module('bkJoga'));

    beforeEach(function () {
        // inject the mock for the http backend
        inject(function (_$httpBackend_) {
            $httpBackend = _$httpBackend_;
        });

        // inject the service to be tested
        inject(function (_GlobalBest_) {
            srv = _GlobalBest_;
        });
    });

    it('should exist', function () {
        expect( !! srv).toBe(true);
    });

    it('query() should return everyone', function () {

        // mock the response to a particular get request
        $httpBackend.whenGET('/jogasok').respond([{
            id: 1,
            name: 'asdfasdf'
        }, {
            id: 2,
            name: '2wrerwert'
        }]);

        // send request to get everyone
        var data = srv.query();

        // flush the pending request
        $httpBackend.flush();
        expect(JSON.stringify(data)).toBe(JSON.stringify([{
            id: 1,
            name: 'asdfasdf'
        }, {
            id: 2,
            name: '2wrerwert'
        }]));
    });

    it('get({id: 1}) should return object with id=1', function () {
        // mock the response to a particular get request
        $httpBackend.whenGET('/jogasok/1').respond({
            id: 1,
            name: 'asdfasdf'
        });
        var datum = srv.get({
            id: 1
        });
        $httpBackend.flush();
        expect(JSON.stringify(datum)).toBe(JSON.stringify({
            id: 1,
            name: 'asdfasdf'
        }));
    });
});

I wrote a fiddle-demo with 3 versions of the service: your original service 'Global', a new version 'GlobalNew' that returns the query() method, and finally a version 'GlobalBest' that returns directly the $resource. Hope this helps.

Problem

Original source