diff -r 000000000000 -r 6474c204b198 dom/settings/tests/test_settings_service.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/settings/tests/test_settings_service.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,143 @@
+"use strict";
+
+const Cu = Components.utils;
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+SimpleTest.waitForExplicitFinish();
+
+XPCOMUtils.defineLazyServiceGetter(this, "SettingsService",
+                                   "@mozilla.org/settingsService;1",
+                                   "nsISettingsService");
+
+let tests = [
+  /* Callback tests */
+  function() {
+    let callbackCount = 10;
+
+    let callback = {
+      handle: function(name, result) {
+        switch (callbackCount) {
+        case 10:
+        case 9:
+          is(result, true, "result is true");
+          break;
+        case 8:
+        case 7:
+          is(result, false, "result is false");
+          break;
+        case 6:
+        case 5:
+          is(result, 9, "result is 9");
+          break;
+        case 4:
+        case 3:
+          is(result, 9.4, "result is 9.4");
+          break;
+        case 2:
+          is(result, false, "result is false");
+          break;
+        case 1:
+          is(result, null, "result is null");
+          break;
+        default:
+          ok(false, "Unexpected call: " + callbackCount);
+        }
+
+        --callbackCount;
+        if (callbackCount === 0) {
+          next();
+        }
+      },
+
+      handleError: function(name) {
+        ok(false, "error: " + name);
+      }
+    };
+
+    let lock = SettingsService.createLock();
+    let lock1 = SettingsService.createLock();
+
+    lock.set("asdf", true, callback, null);
+    lock1.get("asdf", callback);
+    lock.get("asdf", callback);
+    lock.set("asdf", false, callback, null);
+    lock.get("asdf", callback);
+    lock.set("int", 9, callback, null);
+    lock.get("int", callback);
+    lock.set("doub", 9.4, callback, null);
+    lock.get("doub", callback);
+    lock1.get("asdfxxx", callback);
+  },
+
+  /* Observer tests */
+  function() {
+    const XPCOM_SHUTDOWN        = "xpcom-shutdown";
+    const MOZSETTINGS_CHANGED   = "mozsettings-changed";
+
+    const TEST_OBSERVER_KEY     = "test.observer.key";
+    const TEST_OBSERVER_VALUE   = true;
+    const TEST_OBSERVER_MESSAGE = "test.observer.message";
+
+    let observerCount = 2;
+
+    function observer(subject, topic, data) {
+      if (topic === XPCOM_SHUTDOWN) {
+        Services.obs.removeObserver(this, XPCOM_SHUTDOWN);
+        Services.obs.removeObserver(this, MOZSETTINGS_CHANGED);
+        return;
+      }
+
+      if (topic !== MOZSETTINGS_CHANGED) {
+        ok(false, "Event is not mozsettings-changed.");
+        return;
+      }
+
+      data = JSON.parse(data);
+
+      function checkProp(name, type, value) {
+        ok(name in data, "data." + name + " is present");
+        is(typeof data[name], type, "data." + name + " is " + type);
+        is(data[name], value, "data." + name + " is " + value);
+      }
+
+      checkProp("key", "string", TEST_OBSERVER_KEY);
+      checkProp("value", "boolean", TEST_OBSERVER_VALUE);
+      if (observerCount === 2) {
+        checkProp("message", "object", null);
+      } else {
+        checkProp("message", "string", TEST_OBSERVER_MESSAGE);
+      }
+      --observerCount;
+
+      if (observerCount === 0) {
+        next();
+      }
+    }
+
+    Services.obs.addObserver(observer, XPCOM_SHUTDOWN, false);
+    Services.obs.addObserver(observer, MOZSETTINGS_CHANGED, false);
+
+    let lock = SettingsService.createLock();
+    lock.set(TEST_OBSERVER_KEY, TEST_OBSERVER_VALUE, null, null);
+    lock.set(TEST_OBSERVER_KEY, TEST_OBSERVER_VALUE, null, TEST_OBSERVER_MESSAGE);
+  }
+];
+
+function next() {
+  let step = tests.shift();
+  if (step) {
+    try {
+      step();
+    } catch(e) {
+      ok(false, "Test threw: " + e);
+    }
+  } else {
+    SimpleTest.finish();
+  }
+}
+
+next();