Self-incrementing, read-only counter property

run.js

(function IIFE() {
  'use strict';
  var obj = {};
  Object.defineProperties(obj, {
    counter: {
      get: (function IIFE() {
        var def = 0;
        return function() {
          return def++;
        }
      })(),
      enumerable: true
    }
  });
  console.log(obj.counter, obj.counter, obj.counter);
})();