loadtest.html

<h1>Load Testing</h1>

<div>
    <input id="url" type="text"/>
    <button id="start">Start</button>
</div>

<div id="output">
</div>

<script>
var urlText = document.getElementById("url")
var startButton = document.getElementById("start")
var output = document.getElementById("output")

function log(text) {
    output.innerHTML += text + "<br />"
}

startButton.onclick = function () {
    var url = urlText.value
    console.log(url)

    log("Connecting to " + url)
    start(url)
}

function start(url) {
    var socket = new WebSocket(url)

    socket.onopen = function () {
        log("Connected.")
        socket.send(JSON.stringify({name: "user login", data: {name: "hello"}}))

        for (var i=0; i<10000; i++) {
            socket.send(JSON.stringify({name: "user chat", data: {content: "hello world"}}))
        }

        log("10000 message sent.")

        socket.close()

        log("disconnected.")
    }
}
</script>