How to reply to the client and send a message if an error occures on `accept_async` funtion.

[Zai-Kun]

Hey there, I was wondering if there was a way to reply back to the client about the error that had occurred on accept_async but I can't figure out anyway to do so. This is what I thought of at first:

    let ws_stream = if let Ok(ws_stream) = tokio_tungstenite::accept_async(stream).await {
        ws_stream
    } else {
        stream
            .write_all(&make_response(
                "Error, are you using a WS client?",
                "HTTP/1.1 400 Bad Request\r\n\r\n",
            ))
            .await
            .expect("Error while sending the msg");
        return;
    };

fn make_response(content: &str, status_line: &str) -> Vec<u8> {
    format!(
        "{}\r\nContent-Length: {}\r\n\r\n{}",
        status_line,
        content.len(),
        content
    )
    .as_bytes()
    .to_vec()
}

But as you can obviously see, the stream is moved to accept_async function thus cannot be used again. Is there any other way to achieve this? I looked through as many issues as I could but I couldn't an issue related to this. Thanks and sorry if this is dumb as I'm fairly new to rust and tokio-tungstenite.

[daniel-abramov]

If you pass a stream to tokio-tungstenite, it will consume it (generally, there is no guarantee that the stream is usable after as often it's closed by the time you encounter an error).

However, if you're talking about a handshake phase only, this issue has been discussed here: https://github.com/snapview/tungstenite-rs/issues/51