Implement ES6 Array.of()

test/mjsunit/es6/array-of-length-setter.js

+// Copyright 2014 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.
+
+// Based on: https://hg.mozilla.org/mozilla-central/file/d0c3168c3c47/js/src/jit-test/tests/collections/Array-of-length-setter.js
+
+// Flags: --harmony-arrays
+
+
+// Array.of calls a "length" setter if one is present.
+
+var hits = 0;
+var lastObj = null, lastVal = undefined;
+function setter(v) {
+    hits++;
+    lastObj = this;
+    lastVal = v;
+}
+
+// when the setter is on the new object
+function Pack() {
+    Object.defineProperty(this, "length", {set: setter});
+}
+Pack.of = Array.of;
+var pack = Pack.of("wolves", "cards", "cigarettes", "lies");
+assertEquals(lastObj, pack);
+assertEquals(lastVal, 4);
+
+// when the setter is on the new object's prototype
+function Bevy() {}
+Object.defineProperty(Bevy.prototype, "length", {set: setter});
+Bevy.of = Array.of;
+var bevy = Bevy.of("quail");
+assertEquals(lastObj, bevy);
+assertEquals(lastVal, 1);