AngularJs use service from another module - angularjs

Question

I'm trying to use a service from my main module that I'm going to use everywhere.
This is my controller where I would like to use it:
(function () {
'use strict';
angular.module('app.page')
.controller('authCtrl', ['$scope', '$window', '$location','requestService', authCtrl]);
function authCtrl($scope, $window, $location, requestService) {
$scope.login = function() {
requestService.test();
}
}
})();
module:
(function () {
'use strict';
angular.module('app.page',['app']);
})();
Service
(function () {
'use strict';
angular.module('app')
.service('requestService',requestService);
function requestService() {
this.test = function()
{
alert('test');
}
}
})();
But the requestService() is not found in my controller. What am I doing wrong here?
--EDIT--
error message:
angular.js:13424 Error: [$injector:unpr] http://errors.angularjs.org/1.5.3/$injector/unpr?p0=requestServiceProvider%20%3C-%20requestService%20%3C-%20authCtrl
at Error (native)
at http://localhost:3000/bower_components/angular/angular.min.js:6:416
at http://localhost:3000/bower_components/angular/angular.min.js:43:7
at Object.d [as get] (http://localhost:3000/bower_components/angular/angular.min.js:40:270)
at http://localhost:3000/bower_components/angular/angular.min.js:43:69
at d (http://localhost:3000/bower_components/angular/angular.min.js:40:270)
at e (http://localhost:3000/bower_components/angular/angular.min.js:41:1)
at Object.invoke (http://localhost:3000/bower_components/angular/angular.min.js:41:86)
at S.instance (http://localhost:3000/bower_components/angular/angular.min.js:88:235)
at n (http://localhost:3000/bower_components/angular/angular.min.js:64:174) <section data-ui-view="" class="view-container {{main.pageTransition.class}} ng-scope" data-ng-animate="1">

Answer 1

When you defined your service module you didn't provide an empty dependency array to create a new module. Angular will try to find an existing app module and not find it. You need to define your service module like this:
(function () {
'use strict';
angular.module('app', [])
.service('requestService',requestService);
function requestService() {
this.test = function()
{
alert('test');
}
}
})();