LayoutTests/http/tests/site-isolation/post-message.html

<!-- webkit-test-runner [ SiteIsolationEnabled=true ] -->
<script src="/js-test-resources/js-test.js"></script>
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
}

let messageCount = 0;
addEventListener("message", (event) => {
    testPassed("received '" + event.data + "' from " + event.origin);
    messageCount = messageCount + 1;
    if (messageCount == 2) { event.source.postMessage("sending to event source", "*") }
    if (messageCount == 3) { testRunner.notifyDone() }
});

onload = ()=>{
    frame.contentWindow.postMessage("hello", "*")
    frame.contentWindow.postMessage("should not be received", "http://webkit.org")
    frame.contentWindow.postMessage("world", "http://localhost:8000")

    try {
        frame.contentWindow.postMessage("should throw", "about:blank")
    } catch (e) {
        testPassed("posting a message to about:blank threw an exception: " + e)
    }

    try {
        frame.contentWindow.postMessage(window.performance, "/")
    } catch (e) {
        testPassed("posting a non-serializable message threw an exception: " + e)
    }
}

</script>
<iframe src="http://localhost:8000/site-isolation/resources/post-message-to-parent.html" id="frame"></iframe>