<!DOCTYPE html>
<html>
<body>
<script src="../../resources/js-test.js"></script>
<script>
description("Tests that MessagePort.postMessage() works from inside an iframe's unload event handler.");
jsTestIsAsync = true;

let eventsReceivedByFrameWindow = 0;
let eventsReceivedByTopWindow = 0;
let eventsReceivedByTopWindowMessagePort = 0;

function finishIfNecessary()
{
    if (eventsReceivedByTopWindow < 3 || eventsReceivedByTopWindowMessagePort < 3)
        return;

    setTimeout(() => {
        shouldBe("eventsReceivedByFrameWindow", "3");
        shouldBe("eventsReceivedByTopWindow", "3");
        shouldBe("eventsReceivedByTopWindowMessagePort", "3");
        finishJSTest();
    }, 0);
}

onload = () => {
    const testFrame = document.getElementById("testFrame");
    testFrame.contentWindow.addEventListener("message", (e) => {
        const framePort = e.data.port;
        for (let event of ["unload", "pagehide", "visibilitychange"]) {
            testFrame.contentWindow.addEventListener(event, () => {
                eventsReceivedByFrameWindow++;
                window.parent.testPassed(`iframe received "${event}" event`);
                framePort.postMessage({ trigger: event });
                window.parent.postMessage({ trigger: event });
            });
        }
    });

    const channel = new MessageChannel();
    testFrame.contentWindow.postMessage({
        port: channel.port1,
    }, testFrame.contentWindow.origin, [channel.port1]);
    channel.port2.onmessage = (e) => {
        eventsReceivedByTopWindowMessagePort++;
        testPassed("MessagePort in parent frame received message", e.data);
        finishIfNecessary();
    };

    addEventListener("message", (e) => {
        eventsReceivedByTopWindow++;
        testPassed('Parent frame received "message" event', e.data);
        finishIfNecessary();
    });
    setTimeout(() => {
        testFrame.remove();
        setTimeout(finishJSTest, 100);
    }, 0);
};
</script>
<iframe id="testFrame"></iframe>
</body>
</html>