Unit Test for controller in AngularJs Failed - angularjs

Question

Here is my controller:
'use strict';
angular.module('pulseOneApp')
.config(function ($stateProvider) {
$stateProvider.state('about', {
url: '/about',
views: {
'content': {
templateUrl: 'components/version/about.html',
controller: 'AboutController'
}
},
authNotRequired: true
});
})
.controller('AboutController', ['$scope', '$state', 'session', '$pulseOneProps', '$filter', 'propertiesServices', function ($scope, $state, session, $pulseOneProps, $filter, propertiesServices) {
/**
* #function getServerVersion
* #description gets the serverVersion from $pulseOneProps if exist, else makes a REST Api call using propertiesServices.
* #returns string
*/
var getServerVersion = function () {
var systemProperties,serverVersion;
if ((angular.isDefined($pulseOneProps)) && $pulseOneProps !== null) {
systemProperties = $pulseOneProps.getProperties();
if(systemProperties) {
return $filter('filter')(systemProperties, {name: 'server_version'})[0].value;
}
else{
//when the session exist and not able to retrieve $pulseOneProps then do REST Api call and update the systemProperties
session.validateSession().then(function() {
propertiesServices.getPulseOneProperties().then(function (systemProperties) {
serverVersion=$filter('filter')(systemProperties, {name: 'server_version'})[0].value;
// This will update the UI when serverVersion is available
$scope.serverVersion = (serverVersion) ? serverVersion: false;
});
});
}
}
return null; // if none of the above cases are valid then don't display the server version.
};
var serverVersion=getServerVersion();
$scope.serverVersion = (serverVersion) ? serverVersion: false;
$scope.goTo = function() {
session.validateSession().then(function() {
$state.go('app.dashboard');
})
.catch(function() {
$state.go('login');
});
};
}]);
and Here is my Unit Test for this controller to make sure the function goTo is the function:
'use strict';
describe('Controller: AboutCtrl', function () {
// load the controller's module
beforeEach(module('ui.router'));
beforeEach(module('ps.authentication.services'));
beforeEach(module('ps.version'));
beforeEach(module('pulseOneApp'));
beforeEach(module('ps.components.properties'));
var scope, AboutController;
// Initialize the controller and a mock scope
beforeEach(inject(function ($rootScope, _$controller_) {
scope = $rootScope.$new();
AboutController = _$controller_('AboutController', {
$scope: scope
});
scope.$digest();
}));
it('should find to goTo function', function () {
expect(typeof scope.goTo).toBe('function');
});
});
The unit test is failed and I don't know what was wrong with this unit test.
Any suggestion what was the issue here.
Note : The error message is : scope is undefined.
Thanks in advance
-k