LayoutTests/workers/message-port.html

<!DOCTYPE html>
<html>
<head>
<script src="../resources/js-test.js"></script>
</head>
<body>
<script>
description("Sends ArrayBuffers through MessagePorts.");
window.jsTestIsAsync = true;

function test(data, postMessage, checkResult) {
    return new Promise(function (resolve) {
        const channel = new MessageChannel();

        channel.port1.onmessage = event => {
            if (!event.data)
                debug("message data null!");
            postMessage(event.data, event.target);
        };

        channel.port2.onmessage = event => {
            checkResult(event.data);
            resolve();
        };

        postMessage(data, channel.port2);
    });
}

function testEmptyArray(buf) {
    const array = new Float64Array(buf);
    if (!array.length)
        testPassed(`successfully transferred array of length 0`);
    else
        testFailed(`${array} should be a Float64Array of length 0`);
}

const array = new Float64Array([Math.PI]);
const emptyArray = new Float64Array();
const emptyArray2 = new Float64Array();

test(
    { buf: [array.buffer, emptyArray.buffer] },
    (data, port) => port.postMessage({ buf: data.buf }, data.buf),
    data => {
        const array = new Float64Array(data.buf[0]);
        if (array[0] === Math.PI)
            testPassed(`array[0] contains ${Math.PI}`);
        else
            testFailed(`${array[0]} should be ${Math.PI}`);

        testEmptyArray(data.buf[1]);
    }
).then(() =>
    test(
        { buf: emptyArray2.buffer },
        (data, port) => port.postMessage({ buf: data.buf }, [data.buf]),
        data => testEmptyArray(data.buf)
    ),
).then(finishJSTest);
</script>
</body>
</html>