In Javascript, you have created a simple object called Repository
. Although you have a function called init(), it will not be called with the require statement.
You do not need the init function at all, just change Repository.js to
module.exports = Repository;
and this object will be available by requiring Repository.js, just like you did!
var Repo = require('ui/utility/Repository');
var _name = Repo.getProp({name: 'name', default_val: ''});