AngularJS Modules/Scope Sharing

I recently started using AngularJS and the way I'm building my apps now is like this:

MainController.js

var app = angular.module('app', ['SomeController', 'MainController']);

app.controller('MainController', function ($scope) {
    // do some stuff
}

SomeController.js

var SomeController= angular.module('SomeController', []);

SomeController.controller('SomeController', function ($scope) {
    $scope.variable = "test";
    // do some otherstuff
}

The problem that Im' running into is that the scope is not being shared between modules. From MainController I can't get the variable "test" for example.

• What is the best practice for this? Do I store all my controllers in 1 module in 1 file?
• How can i have 1 page with 2 controllers and share the $scope between them, or is it OK to put everything in just one controller ?