// Copyright 2016 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Create a prototype object which has a lot of fast properties. var body = ""; for (var i = 0; i < 100; i++) { body += `this.a${i} = 0;\n`; } var Proto = new Function(body); function A() {} A.prototype = new Proto(); // Create a object and add properties that already exist in the prototype. // At some point the object will turn into a dictionary mode and one of // the fast details from the prototype will be reinterpreted as a details // for a new property ... var o = new A(); for (var i = 0; i < 100; i++) { o["a" + i] = i; } // ... which will break the enumeration order of the slow properties. var names = Object.getOwnPropertyNames(o); for (var i = 0; i < 100; i++) { assertEquals("a" + i, names[i]); }