diff -r 000000000000 -r 6474c204b198 dom/system/gonk/tests/marionette/test_screen_state.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/system/gonk/tests/marionette/test_screen_state.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+MARIONETTE_TIMEOUT = 10000;
+
+let Services = SpecialPowers.Services;
+
+function testScreenState(on, expected, msg) {
+  // send event to RadioInterface
+  Services.obs.notifyObservers(null, 'screen-state-changed', on);
+  // maybe rild/qemu needs some time to process the event
+  window.setTimeout(function() {
+    runEmulatorCmd('gsm report creg', function(result) {
+      is(result.pop(), 'OK', '\'gsm report creg\' successful');
+      ok(result.indexOf(expected) !== -1, msg);
+      runNextTest();
+    })}, 1000);
+}
+
+function testScreenStateDisabled() {
+  testScreenState('off', '+CREG: 1', 'screen is disabled');
+}
+
+function testScreenStateEnabled() {
+  testScreenState('on', '+CREG: 2', 'screen is enabled');
+}
+
+let tests = [
+  testScreenStateDisabled,
+  testScreenStateEnabled
+];
+
+function runNextTest() {
+  let test = tests.shift();
+  if (!test) {
+    cleanUp();
+    return;
+  }
+
+  test();
+}
+
+function cleanUp() {
+  finish();
+}
+
+runNextTest();