function test() { waitForExplicitFinish(); Services.ww.registerNotification(function (aSubject, aTopic, aData) { if (aTopic == "domwindowopened") { Services.ww.unregisterNotification(arguments.callee); ok(true, "duplicateTabIn opened a new window"); aSubject.addEventListener("load", function () { aSubject.removeEventListener("load", arguments.callee, false); executeSoon(function () { aSubject.close(); finish(); }); }, false); } }); duplicateTabIn(gBrowser.selectedTab, "window"); }