es6.reflect.set.js

// 26.1.13 Reflect.set(target, propertyKey, V [, receiver])
var dP = require('./_object-dp');
var gOPD = require('./_object-gopd');
var getPrototypeOf = require('./_object-gpo');
var has = require('./_has');
var $export = require('./_export');
var createDesc = require('./_property-desc');
var anObject = require('./_an-object');
var isObject = require('./_is-object');

function set(target, propertyKey, V /* , receiver */) {
  var receiver = arguments.length < 4 ? target : arguments[3];
  var ownDesc = gOPD.f(anObject(target), propertyKey);
  var existingDescriptor, proto;
  if (!ownDesc) {
    if (isObject(proto = getPrototypeOf(target))) {
      return set(proto, propertyKey, V, receiver);
    }
    ownDesc = createDesc(0);
  }
  if (has(ownDesc, 'value')) {
    if (ownDesc.writable === false || !isObject(receiver)) return false;
    existingDescriptor = gOPD.f(receiver, propertyKey) || createDesc(0);
    existingDescriptor.value = V;
    dP.f(receiver, propertyKey, existingDescriptor);
    return true;
  }
  return ownDesc.set === undefined ? false : (ownDesc.set.call(receiver, V), true);
}

$export($export.S, 'Reflect', { set: set });