A simple example of how to share code between the front and back ends. This file could be run in either environment and work in both, without code duplication.

sharing.js

var config = {
    version: '3.1.4'
};

// Frontend
if (window) {
    window.config = config;

// Backend
} else if (typeof module !== 'undefined' && module.exports) {
    module.exports = config;
}