websocket - potential bug, weird behavior with ping/pong, maybe I'm missing something

[robobun]

minimal reproducible

const server = Bun.serve({
    fetch(req) {
        console.log('SERVER incoming request');
        server.upgrade(req);
    },
    websocket: {
        open(ws) {
            console.log(`SERVER open`);
            ws.ping(); // removing this fixes the issue - this is probably the buggy part
        },
        close(ws, code, reason) {
            console.log(`SERVER close: code=${code} reason=${reason}`);
        },
        message(ws, message) {
            console.log(`SERVER message: ${Bun.inspect(message)}`);
        }
    },
    port: 1337,
});

const ws = new WebSocket('ws://127.0.0.1:1337');

ws.onopen = async () => { // same behavior with addEventHandler
    ws.send('this message sends just fine');

    for await (const _ of console) { // removing this fixes the issue
        ws.send('hi'); // causes closure upon first line
    }
};

output with code shown above

% bun run index.js
SERVER incoming request
SERVER open
SERVER message: "this message sends just fine"

output with server ws.ping() or client for await (...) excluded

% bun run index.js
SERVER incoming request
SERVER open
SERVER message: "this message sends just fine"
  <-- ENTER (for await over console)
SERVER close: code=1006 reason=

I haven't a clue what's actually causing this, but the presence or absence of a ping doesn't seem like it should cause any problems. I previously had handlers for ping/pong messages, I was just testing them out (no intervals yet), but the issue was there before as well - I tried to reduce the fluff as much as possible to get a simple reproducible

Originally reported on Discord: websocket - potential bug, weird behavior with ping/pong, maybe I'm missing something

[DeveloperHarris]

Encountering this issue as well. The bun websocket client seems to have a bug in regards to receiving pings that causes the connection to close?

I also have a simple ServerWebSocket setup and a WebSocket like you, and am able to get some intervaled pings to work, but not others.

ping("42") for example works, but ping() or ping("hello") does not.

Very strange.

// Server
let timer;

Bun.serve({
    fetch(req, server) {
        // upgrade the request to a WebSocket
        if (server.upgrade(req)) {
            return; // do not return a Response
        }
        return new Response("Upgrade failed :(", { status: 500 });
    },
    websocket: {
        open(ws) {
            timer = setInterval(() => {
                console.log("server tx'd ping. ");
                ws.ping("test");
            }, 2000);
        },
        message(ws, message) {
            let hexString = message.toString("hex");
            let hexWithSpaces = hexString.match(/.{1,2}/g)!.join(" ");
            console.log("server rx'd:", hexWithSpaces);
        },
        close(ws, code, message) {
            console.log("server closed:", code, message);
            clearInterval(timer!);
        },
    },
});

// Client
const socket = new WebSocket("ws://localhost:3000");

socket.addEventListener("message", (event) => {
    console.log("client rx'd:", event.data);
});

socket.addEventListener("error", (event) => {
    console.error("client error:", event);
});

socket.addEventListener("close", (event) => {
    console.log("client close:", event.code, event.reason);
});

ws.ping("test") fails:

server tx'd ping.
server closed: 1006
client close: 1006 Connection ended

but ws.ping("42") works:

server tx'd ping.
server tx'd ping.
server rx'd: 34 32 b6 67 88 c1 5c 13 bc f3
server tx'd ping.
server tx'd ping.
server rx'd: 34 32 4b f3 7a 4d bf ba 4e 7f