_object-create.js 1.47 KB
// 19.1.2.2 / 15.2.3.5 Object.create(O [, Properties])
var anObject = require('./_an-object');
var dPs = require('./_object-dps');
var enumBugKeys = require('./_enum-bug-keys');
var IE_PROTO = require('./_shared-key')('IE_PROTO');
var Empty = function () { /* empty */ };
var PROTOTYPE = 'prototype';

// Create object with fake `null` prototype: use iframe Object with cleared prototype
var createDict = function () {
  // Thrash, waste and sodomy: IE GC bug
  var iframe = require('./_dom-create')('iframe');
  var i = enumBugKeys.length;
  var lt = '<';
  var gt = '>';
  var iframeDocument;
  iframe.style.display = 'none';
  require('./_html').appendChild(iframe);
  iframe.src = 'javascript:'; // eslint-disable-line no-script-url
  // createDict = iframe.contentWindow.Object;
  // html.removeChild(iframe);
  iframeDocument = iframe.contentWindow.document;
  iframeDocument.open();
  iframeDocument.write(lt + 'script' + gt + 'document.F=Object' + lt + '/script' + gt);
  iframeDocument.close();
  createDict = iframeDocument.F;
  while (i--) delete createDict[PROTOTYPE][enumBugKeys[i]];
  return createDict();
};

module.exports = Object.create || function create(O, Properties) {
  var result;
  if (O !== null) {
    Empty[PROTOTYPE] = anObject(O);
    result = new Empty();
    Empty[PROTOTYPE] = null;
    // add "__proto__" for Object.getPrototypeOf polyfill
    result[IE_PROTO] = O;
  } else result = createDict();
  return Properties === undefined ? result : dPs(result, Properties);
};