Variable not defined in Jasmine test case although its in scope

I want to test a controller where it listens on an event to do some stuff. The event handler is dependent on a global variable called Main. I'm trying to unit test the event listener by mocking all dependencies but Karma throws error :

ReferenceError: Main is not defined

Angular Code :

App.controller('AppController', ['$scope', function($scope){
    $scope.$on('$viewContentLoaded', function() {
        Main.initComponents(); // init core components
    });
}]);

Spec file :

describe("App", function () {
    var scope, AppController, Main;
    describe("Login", function () {
        beforeEach(module("App"));
        beforeEach(inject(['$rootScope', '$controller', function($rootScope, $controller){
            scope = $rootScope.$new();
            Main = jasmine.createSpyObj("Main",["initComponents"]);
            AppController = $controller('AppController', {$scope : scope});
        }]));
        it("should call initComponents() on Main module on $viewContentLoaded event", inject(['$rootScope', function ($rootScope) {
            $rootScope.$broadcast('$viewContentLoaded');
            expect(Main.initComponents).toHaveBeenCalled();
        }]));
    });
});

karma.conf.js :

module.exports = function(config){
    config.set({

        basePath : './',

        files : [
            'app/bower_components/angular/angular.js',
            'app/bower_components/oclazyload/dist/oclazyLoad.min.js',
            'app/bower_components/angular-ui-router/release/angular-ui-router.min.js',
            'app/bower_components/angular-mocks/angular-mocks.js',
            'app/**/app.js',
            'app/**/controllers.js',
            'app/**/services.js',
            'app/**/directives.js',
            'app/**/filters.js',
            'app/**/routes.js',
            'app/**/specs.js'
        ],

        autoWatch : true,

        frameworks: ['jasmine'],

        browsers : ['Chrome'],

        plugins : [
            'karma-chrome-launcher',
            'karma-firefox-launcher',
            'karma-jasmine',
            'karma-junit-reporter'
        ],

        junitReporter : {
            outputFile: 'test_out/unit.xml',
            suite: 'unit'
        }

    });
};

What is the problem? Thanks for help.