Calling a generator function returns a generator object

test/mjsunit/harmony/generators-objects.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 27 matching lines @@
   function* g4() { var x = 10; yield 1; return x; }
   // Temporary variable context allocation
   function* g5(l) { "use strict"; yield 1; for (let x in l) { yield x; } }
 
   g1();
   g2();
   g3();
   g4();
   g5(["foo"]);
 }
+TestContextAllocation();
 
-TestContextAllocation();
+
+// Test the properties and prototype of a generator object.
+function TestGeneratorObject() {
+  function* g() { yield 1; }
+
+  var iter = g();
+  assertSame(g.prototype, Object.getPrototypeOf(iter));
+  assertTrue(iter instanceof g);
+  assertEquals([], Object.getOwnPropertyNames(iter));
+  assertTrue(iter !== g());
+
+  // g() is the same as new g().
+  iter = new g();
+  assertSame(g.prototype, Object.getPrototypeOf(iter));
+  assertTrue(iter instanceof g);
+  assertEquals([], Object.getOwnPropertyNames(iter));
+  assertTrue(iter !== new g());
+}
+TestGeneratorObject();