async_test(t => {
const crossOriginURL = new URL("resources/origin.html", self.location.href).href.replace("://", "://天気の良い日."),
frame = document.createElement("iframe");
frame.src = crossOriginURL;
document.body.appendChild(frame);
t.add_cleanup(() => frame.remove());
self.onmessage = t.step_func_done(e => {
assert_equals(e.data, self.origin.replace("://", "://xn--n8j6ds53lwwkrqhv28a."));
});
}, "Serialization of BroadcastChannel origin");