[Workers] [WebSocket Helper] Error after disconnecting when client sent a message

[JustJoostNL]

What version of Hono are you using?

4.11.3

What runtime/platform is your app running on? (with version if possible)

Cloudflare Workers

What steps can reproduce the bug?

hono.get(
  "/ws",
  upgradeWebSocket((c) => ({
    onMessage: async (ev: MessageEvent, ws) => {
      ws.send("hi");
    },
  })),
);

1. Connect to the websocket.
2. Send a message to the server as client.
3. Observe the hi response.
4. Disconnect the websocket.
5. Observe the Cloudflare Workers error: Uncaught Error: The Workers runtime canceled this request because it detected that your Worker's code had hung and would never generate a response. Refer to: https://developers.cloudflare.com/workers/observability/errors/.

What is the expected behavior?

When disconnecting after sending a message it should not show that error. Interestingly, when connecting, and disconnecting right after without sending a message, it works fine.

What do you see instead?

The following unexpected Cloudflare Workers error: Uncaught Error: The Workers runtime canceled this request because it detected that your Worker's code had hung and would never generate a response. Refer to: https://developers.cloudflare.com/workers/observability/errors/.

Additional information

No response

[JustJoostNL]

This was actually my bad, and I solved this by adding the following to the upgrade helper:

onClose: (_ev, ws) => {
  ws.close();
},

[JustJoostNL]

I'm afraid I have to reopen this, calling ws.close() only solved this in local development with Wrangler. When using the --remote option or when deploying this, this actually caused a second "hanging error". After removing the ws.close() again, it went back to only a single "hanging error", both locally and remote/deployed.

What's wrong here?