ES6 Object.getPropertyNames

Object.getPropertyNames.js

Object.getPropertyNames ||
Object.defineProperty(Object, "getPropertyNames", {
  value: function(obj) {
    var propertyNames = [];
    do {
      propertyNames.push.apply(propertyNames, Object.getOwnPropertyNames(obj));
      obj = Object.getPrototypeOf(obj);
    } while (obj);
    // get unique property names
    obj = {};
    for(var i = 0, len = propertyNames.length; i < len; i++) {
      obj[propertyNames[i]] = 1;
    }
    return Object.keys(obj);
  }
});