index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        // const ws = new WebSocket('ws://localhost:8888/');
        const ws = new WebSocket('ws://192.168.11.1:8888/');
        ws.binaryType = "arraybuffer";


        ws.onclose = function (t, ev) {
            console.log('onclose');
        }
        ws.onerror = function (t, ev) {
            console.log('onerror');
        }
        ws.onopen = function (t, ev) {
            console.log('onopen');
        }
        ws.onmessage = function (event) {
            console.log('onmessage:');
            if (event.data instanceof ArrayBuffer) {
                // binary frame
                const view = new DataView(event.data);
                console.log(event.data);
            } else {
                // text frame
                console.log(event.data);
            }
        }
        function sendBinary() {
            console.log("sendBinary()")
            const data = new Uint8Array(65535);
            data.forEach(function (v, i, arr) {
                arr[i] = i;
            })
            ws.send(data);
        }
        function sendText() {
            console.log("sendText()")
            ws.send("hello websocket");
        }
    </script>
    <button onclick="sendBinary()">sendBinary</button>
    <button onclick="sendText()">sendText</button>
</body>

</html>