js调用火币解析websocket

<script type="text/javascript">
    var sock = null;
    var wsuri = "wss://api.huobi.vn/ws";
    window.onload = function() {
        console.log("onload");
        sock = new WebSocket(wsuri);
        sock.onopen = function() {
            console.log("connected to " + wsuri);
            sock.send(JSON.stringify({"sub":"market.btcusdt.trade.detail","id":"BTC"}))
        }
        sock.onclose = function(e) {
            console.log("connection closed (" + e.code + ")");
        }
        sock.onmessage = function(evt) {
             if(evt.data instanceof Blob){
                var result = '';
                var reader = new FileReader();
                reader.onload = function() {
                     result = JSON.parse(pako.inflate(reader.result,{to:'string'}));
                     if(result.ping){
                        sock.send(JSON.stringify({pong:result.ping}));
                     }
                     console.log(result)
                 }
                 reader.readAsBinaryString(evt.data);
             }
        }
    };
</script>