diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_7/geniter/pi-generator.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_7/geniter/pi-generator.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER     = "(none)";
+var summary = "A (slow) generator of pi";
+var actual, expect;
+
+printBugNumber(BUGNUMBER);
+printStatus(summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+function pi()
+{
+  var val = 0;
+  var curr = 1;
+  var isNeg = false;
+  while (true)
+  {
+    if (isNeg)
+      yield val -= 4/curr;
+    else
+      yield val += 4/curr;
+    curr += 2;
+    isNeg = !isNeg;
+  }
+}
+
+var failed = false;
+var it = pi();
+
+var vals =
+  [4,
+   4 - 4/3,
+   4 - 4/3 + 4/5,
+   4 - 4/3 + 4/5 - 4/7];
+
+try
+{
+  for (var i = 0, sz = vals.length; i < sz; i++)
+    if (it.next() != vals[i])
+      throw vals[i];
+}
+catch (e)
+{
+  failed = e;
+}
+
+
+
+expect = false;
+actual = failed;
+
+reportCompare(expect, actual, summary);