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

test/mjsunit/harmony/array-of.js

Index: test/mjsunit/harmony/array-of.js
diff --git a/test/mjsunit/harmony/array-of.js b/test/mjsunit/harmony/array-of.js
index adf7cb547cdae9eebd9fdec14f01c8d562526e65..9164b21efec8fe393de83ce1a3ec61ba9084602e 100644
--- a/test/mjsunit/harmony/array-of.js
+++ b/test/mjsunit/harmony/array-of.js
@@ -182,3 +182,38 @@ assertThrows(function() { new Array.of() }, TypeError);  // not a constructor
   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++; }
+    });
+  }
+  // Check that exotic was defined right
+  var instance = new exotic();
+  assertEquals(2, instance[0]);
+  instance[0] = 1;
+  assertEquals(2, instance[0]);
+  assertEquals(1, setterCalled);
+  // Accessor properties can't be overwritten with DefineOwnProperty
+  assertThrows(function () { Array.of.call(exotic, 1); }, TypeError);
+  assertEquals(1, 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);
+})();