services.js

angular.module('angular-client-side-auth')
.factory('Auth', function($http, $rootScope, $cookieStore){

    // ...

    $rootScope.accessLevels = accessLevels;
    $rootScope.userRoles = userRoles;

    return {
        authorize: function(accessLevel, role) {
            if(role === undefined)
                role = $rootScope.user.role;
            return accessLevel & role;
        },

        isLoggedIn: function(user) {
            if(user === undefined)
                user = $rootScope.user;
            return user.role === userRoles.user || user.role === userRoles.admin;
        },

        register: function(user, success, error) {
            $http.post('/register', user).success(success).error(error);
        },

        login: function(user, success, error) {
            $http.post('/login', user).success(function(user){
                $rootScope.user = user;
                success(user);
            }).error(error);
        },

        logout: function(success, error) {
            $http.post('/logout').success(function(){
                $rootScope.user = {
                    username = '',
                    role = userRoles.public
                };
                success();
            }).error(error);
        },

        accessLevels: accessLevels,
        userRoles: userRoles
    };
});

FYI, line 36 and 37 do not correctly set object properties, should be : instead of =