Websocket are blocking HttpServer shutdown

[hakkanicko]

Version: Deno 2.2.3

Context

I made a websocket proxy with Deno. And when I try to stop it, the server won't stop if there is one active WebSocket.
Closing the websocket won't fix the issue.

How to reproduce it

Create two files:

// proxy.ts

const abortController = new AbortController();

function websocketProxy(request: Request, _info: any) {
  if (request.headers.get("upgrade") !== "websocket") {
    return new Response("Not a websocket request", { status: 400 });
  }
  const { response, socket } = Deno.upgradeWebSocket(request);

  const remoteSocket = new WebSocket("http://localhost:3031");

  socket.addEventListener("message", (event) => {
    remoteSocket.send(event.data);
  });

  remoteSocket.addEventListener("message", (event) => {
    socket.send(event.data);
  });

  socket.addEventListener("close", () => {
    remoteSocket.close();
  });

  remoteSocket.addEventListener("close", () => {
    socket.close();
  });

  socket.addEventListener("error", (_event) => {
    remoteSocket.close();
  });

  remoteSocket.addEventListener("error", (_event) => {
    socket.close();
  });

  abortController.signal.addEventListener("abort", () => {
    socket.close(1000, "aborted");
    remoteSocket.close(1000, "aborted");
  });

  return response;
}

function runnerAroundTheServer() {
  const runningServer = Deno.serve({
    signal: abortController.signal,
    port: 3030,
  }, websocketProxy);

  return {
    async shutdown() {
      abortController.abort();
      await runningServer.finished;
    },
  };
}

const runningApp = runnerAroundTheServer();

Deno.addSignalListener("SIGINT", runningApp.shutdown);
Deno.addSignalListener("SIGTERM", runningApp.shutdown);

// websocketEcho.ts
function reverseMessageServer(request: Request, _info: any) {
  if (request.headers.get("upgrade") !== "websocket") {
    return new Response("Not a websocket request", { status: 400 });
  }
  const { response, socket } = Deno.upgradeWebSocket(request);

  socket.addEventListener("message", (event) => {
    socket.send(event.data.toString().split("").reverse().join(""));
  });

  return response;
}

Deno.serve({
  port: 3031,
}, reverseMessageServer);

Run deno run -A proxy.ts and deno run -A websocketEcho.ts

Use a websocket client to connect to the proxy, like websocat ws://localhost:3030/

Try to quit the proxy.ts using CTRL+C

Expected behavior

The server should stop. And the socket and remoteSocket should close.

Actual behavior

• remoteSocket closes
• socket doesn't close
• the server doesn't stop
• the socket closes if you try to send a message to the proxy.