使用模拟工厂在Jasmine中测试嵌套的Promise

Question

I am building AngularJS application and I am trying to unit test it. I want to inject mock service instead of real dependencies.

This is the service I am trying to test:

.factory('LoginService',['Login', function(Login){
    return {
        getActiveUser: function() {
            return Login.query({}).$promise.then(
                function (users) {
                    return users[0];
                },
                function (error) {
                    console.log(error);
                }
            );
        }
    };
}]);

It is a simple service that returns the first user from the list of all users. Bellow is my attempt of writing the unit test with mocks, but unsuccessful.

....
beforeEach(module('loginModule', function($provide) {

    mockedService = {
        getActiveUser: function() {
            return {
                then: function(callback) {
                    return callback({name: 'John'});
                }
            };
        }
    };

    $provide.value('LoginService', mockedService);

}));

beforeEach(inject(function (_LoginService_,  _Login_, _$httpBackend_, $rootScope) {
    LoginService = _LoginService_;
    Login = _Login_;
    scope = $rootScope;
    httpBackend = _$httpBackend_;

    spyOn(mockedService, 'getActiveEnvironment').andCallThrough();
}));

describe('getActiveUser', function () {
    it('should call the function', function() {
        LoginService.getActiveUser();
        expect(mockedService.getActiveUser).toHaveBeenCalled();
    });

    it('should return active user', function() {
        var user = {};

        mockedService.getActiveUser().then(
            function (env) {
                user = env;
            }
        )

        expect(user.name).toBe("John");

    });
});

I was able to make test passes using spies and injecting the services method directly. Now I want to achieve the same, but with mocked instance. The first test passes but the second one fails.Anybody has the idea?

Answer 1

Try to mock service this way:

mockedService = {
    getActiveUser: function() {
        return $q.when({username: 'Thomas'});
    }
}

then you can spy it:

spyOn(mockedService, 'getActiveUser').and.callThrough();

and in thes you would run it

mockedService.getActiveUser().then(function(env) {
    user = env;
});

Also you can manually create promise-like API:

mockedService = {
    getActiveUser: function() {
        return {
            then: function(callback) {
                return callback({username: 'Thomas'});
            }
        };
    }
}