diff -r 000000000000 -r 6474c204b198 testing/xpcshell/example/unit/test_profile.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/xpcshell/example/unit/test_profile.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,19 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+function run_test()
+{
+  let profd = do_get_profile();
+  do_check_true(profd.exists());
+  do_check_true(profd.isDirectory());
+  let dirSvc = Components.classes["@mozilla.org/file/directory_service;1"]
+                         .getService(Components.interfaces.nsIProperties);
+  let profd2 = dirSvc.get("ProfD", Components.interfaces.nsILocalFile);
+  do_check_true(profd2.exists());
+  do_check_true(profd2.isDirectory());
+  // make sure we got the same thing back...
+  do_check_true(profd.equals(profd2));
+}