diff -r 000000000000 -r 6474c204b198 addon-sdk/source/test/test-module.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/addon-sdk/source/test/test-module.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,37 @@
+/* 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/. */
+
+"use strict";
+
+/** Disabled because of Bug 672199
+exports["test module exports are frozen"] = function(assert) {
+  assert.ok(Object.isFrozen(require("sdk/hotkeys")),
+            "module exports are frozen");
+};
+
+exports["test redefine exported property"] = function(assert) {
+  let hotkeys = require("sdk/hotkeys");
+  let { Hotkey } = hotkeys;
+  try { Object.defineProperty(hotkeys, 'Hotkey', { value: {} }); } catch(e) {}
+  assert.equal(hotkeys.Hotkey, Hotkey, "exports can't be redefined");
+};
+*/
+
+exports["test can't delete exported property"] = function(assert) {
+  let hotkeys = require("sdk/hotkeys");
+  let { Hotkey } = hotkeys;
+
+  try { delete hotkeys.Hotkey; } catch(e) {}
+  assert.equal(hotkeys.Hotkey, Hotkey, "exports can't be deleted");
+};
+
+exports["test can't override exported property"] = function(assert) {
+  let hotkeys = require("sdk/hotkeys");
+  let { Hotkey } = hotkeys;
+
+  try { hotkeys.Hotkey = Object } catch(e) {}
+  assert.equal(hotkeys.Hotkey, Hotkey, "exports can't be overriden");
+};
+
+require("test").run(exports);