WebSocketError: Connection refused in bun `--bun` runtime

[UPDATED]

Environment

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• Operating System: Darwin
• Node Version: v22.14.0
• Nuxt Version: -
• CLI Version: 3.22.5
• Nitro Version: 2.11.1
• Package Manager: pnpm@10.5.2
• Builder: -
• User Config: -
• Runtime Modules: -
• Build Modules: -

---

bun 1.2.4

Reproduction

https://github.com/jamaluddinrumi/can-not-send-anything-websocket

or

just start with starter template

follow websocket usage

run

bun --bun run dev

and type in the terminal, i use websocat tool to checking the websocket logs

websocat ws://localhost:3000 -v

it returns

[INFO  websocat::lints] Auto-inserting the line mode
[INFO  websocat::stdio_threaded_peer] get_stdio_peer (threaded)
[INFO  websocat::ws_client_peer] get_ws_client_peer
[INFO  websocat::net_peer] Failure during connecting TCP: Connection refused (os error 61)
websocat: WebSocketError: Connection refused (os error 61)
websocat: error running

without received sent message Welcome ${peer}!

Describe the bug

it should sent Welcome ${peer}! message

Additional context

No response

Logs

Start by reproducing the issue with the starter template and the WebSocket usage guide using bun --bun run dev, then connect with websocat ws://localhost:3000 -v. Trace why the Bun runtime refuses the connection; done means the development server accepts the WebSocket connection and sends the expected Welcome ${peer}! message.