WebSocketStream unhandled rejection

[sergeysolovev]

Version: Deno 1.45.5
OS: Linux

Steps: start a server which accepts a ws connection, not necessary to send anything from the server. Can use this one from another issue I’ve filed, just please comment out the part where it sends tons of messages. Start the client script (below). Exit the server script, in my case the client gets Unexpected EOF error.

Somehow I get unhandled rejection, though in the client code below I can’t see where it pops up from. Is possible it gets thrown and not intercepted somewhere internally?

const wss = new WebSocketStream('ws://localhost:3333/');
const conn = await wss.opened;
const reader = conn.readable.getReader();

addEventListener('unhandledrejection', (event) => {
  event.preventDefault();
  console.log('unhandledrejection', event);
});

wss.closed.then((x) => {
  console.log('closed', x);
}).catch((err) => {
  console.log('err', err);
});

while (true) {
  try {
    const { value, done } = await reader.read();
    if (done) {
      console.log('done');
      break;
    }
    console.log('msg', value);
  } catch (error) {
    console.log('read_loop_error', error);
    break;
  }
}

[sergeysolovev]

The client script output looks like this to me:

$ deno run -A wss_repro.ts
read_loop_error WebSocketError {
  message: "Unexpected EOF",
  name: "WebSocketError",
  closeCode: null,
  reason: ""
}
err WebSocketError {
  message: "Unexpected EOF",
  name: "WebSocketError",
  closeCode: null,
  reason: ""
}
unhandledrejection PromiseRejectionEvent {
  bubbles: false,
  cancelable: true,
  composed: false,
  currentTarget: Window {},
  defaultPrevented: true,
  eventPhase: 2,
  srcElement: null,
  target: Window {},
  returnValue: false,
  timeStamp: 0,
  type: "unhandledrejection",
  promise: Promise {
    <rejected> WebSocketError {
      message: "Unexpected EOF",
      name: "WebSocketError",
      closeCode: null,
      reason: ""
    }
  },
  reason: WebSocketError {
    message: "Unexpected EOF",
    name: "WebSocketError",
    closeCode: null,
    reason: ""
  }
}

[sergeysolovev]

Just in case: to get Unexpected EOF I exit the server process without closing the connection on the server side

[sergeysolovev]

Seems to be related #22165, but the fix mentioned there doesn’t work in my case