JSTests/test262/test/built-ins/Proxy/set/return-true-target-property-accessor-is-configurable-set-is-undefined.js

// Copyright (C) 2015 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
es6id: 9.5.9
description: >
    [[Set]] ( P, V, Receiver)

    Returns true if trap returns true and target property accessor is
    configurable and set is undefined.
features: [Proxy, Reflect, Reflect.set]
---*/

var target = {};
var handler = {
  set: function(t, prop, value, receiver) {
    return true;
  }
};
var p = new Proxy(target, handler);

Object.defineProperty(target, "attr", {
  configurable: true,
  set: undefined
});

assert(Reflect.set(p, "attr", "bar"));