ES 2015 Proxy sample based on http://learn.javascript.ru/proxy

proxy-sample.js

(function () {
    'use strict';

    let user = {};

    let proxy = new Proxy(user, {
      get(target, prop) {
        console.log(`Чтение ${prop}`);
        return target[prop];
      },
      set(target, prop, value) {
        console.log(`Запись ${prop} ${value}`);
        target[prop] = value;
        return true;
      }
    });

    proxy.firstName = "Ilya"; // write

    proxy.firstName; // read

    console.log(user.firstName); // Ilya
})();