1 files changed, 42 insertions, 0 deletions
diff --git a/addon-sdk/source/test/test-preferences-target.js b/addon-sdk/source/test/test-preferences-target.js
new file mode 100644
index 000000000..a534bc7ab
--- /dev/null
+++ b/addon-sdk/source/test/test-preferences-target.js
@@ -0,0 +1,42 @@
+/* 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';
+
+const { PrefsTarget } = require('sdk/preferences/event-target');
+const { get, set, reset } = require('sdk/preferences/service');
+const { Loader } = require('sdk/test/loader');
+const { setTimeout } = require('sdk/timers');
+
+const root = PrefsTarget();
+
+exports.testPrefsTarget = function(assert, done) {
+  let loader = Loader(module);
+  let pt = loader.require('sdk/preferences/event-target').PrefsTarget({});
+  let name = 'test';
+
+  assert.equal(get(name, ''), '', 'test pref is blank');
+
+  pt.once(name, function() {
+    assert.equal(pt.prefs[name], 2, 'test pref is 2');
+
+    pt.once(name, function() {
+      assert.fail('should not have heard a pref change');
+    });
+    loader.unload();
+    root.once(name, function() {
+      assert.pass('test pref was changed');
+      reset(name);
+
+      // NOTE: using setTimeout to make sure that the other listener had
+      //       a chance to fail
+      // end test
+      setTimeout(done);
+    });
+    set(name, 3);
+  });
+
+  pt.prefs[name] = 2;
+};
+
+require('sdk/test').run(exports);