In Array.of and Array.from, fall back to DefineOwnProperty

test/mjsunit/harmony/array-of.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 Mozilla Array.of() tests at http://dxr.mozilla.org/mozilla-central/source/js/src/jit-test/tests/collections
 
 // Flags: --harmony-arrays
 
 
 
@@ skipping 164 matching lines @@
 });
 
 
 (function testBoundConstructor() {
   var boundFn = (function() {}).bind(null);
   var instance = Array.of.call(boundFn, 1, 2, 3);
   assertEquals(instance.length, 3);
   assertEquals(instance instanceof boundFn, true);
   assertEquals(Array.isArray(instance), false);
 })();
+
+(function testDefinesOwnProperty() {
+  // Assert that [[DefineOwnProperty]] is used in ArrayFrom, meaning a
+  // setter isn't called, and a failed [[DefineOwnProperty]] will throw.
+  var setterCalled = 0;
+  function exotic() {
+    Object.defineProperty(this,  '0', {
+      get: function() { return 2; },
+      set: function() { setterCalled++; }
+    });
+  }
+  // Non-configurable properties can't be overwritten with DefineOwnProperty
+  assertThrows(function () { Array.of.call(exotic, 1); }, TypeError);
+  // The setter wasn't called
+  assertEquals(0, setterCalled);
+
+  // Check that array properties defined are writable, enumerable, configurable
+  function ordinary() { }
+  var x = Array.of.call(ordinary, 2);
+  var xlength = Object.getOwnPropertyDescriptor(x, 'length');
+  assertEquals(1, xlength.value);
+  assertEquals(true, xlength.writable);
+  assertEquals(true, xlength.enumerable);
+  assertEquals(true, xlength.configurable);
+  var x0 = Object.getOwnPropertyDescriptor(x, 0);
+  assertEquals(2, x0.value);
+  assertEquals(true, xlength.writable);
+  assertEquals(true, xlength.enumerable);
+  assertEquals(true, xlength.configurable);
+})();