NetworkError caused by WebSocketStream cannot be caught?

[masx200]

Version: Deno 1.40.1

const listener = Deno.listen({ port: 9000, transport: "tcp" });

try {
    for await (const conn of listener) {
        (async () => {
            const ws = new WebSocketStream("ws://loca99999999999lhost:8000", {
                headers: {
                    "x-Protocol": "Transmission Control",
                    "X-Destination-Address": "www.ba99999999999idu.com",
                    "X-Destination-Port": "80",
                },
            });
            // console.log(ws);
            try {
                const webConn = await ws.opened; //.catch(console.error);
                // console.log(webConn);
                conn.readable.pipeTo(webConn.writable).catch(function (e) {
                    try {
                        ws.close();
                        conn.close();
                    } catch (e) {
                        console.error(e);
                    }

                    return console.error(e);
                });
                webConn.readable.pipeTo(conn.writable).catch(function (e) {
                    try {
                        ws.close();
                        conn.close();
                    } catch (e) {
                        console.error(e);
                    }
                    return console.error(e);
                });
            } catch (error) {
                console.error(error);
                try {
                    ws.close();
                    conn.close();
                } catch (e) {
                    console.error(e);
                }
            }
        })().catch(console.error);
    }
} catch (error) {
    console.error(error);
}

deno run --unstable -A ./client.ts
⚠️  The `--unstable` flag is deprecated and will be removed in Deno 2.0. Use granular `--unstable-*` flags instead.
Learn more at: https://docs.deno.com/runtime/manual/tools/unstable_flags
DOMException: failed to connect to WebSocket: 不知道这样的主机。 (os error 11001)
    at new DOMException (ext:deno_web/01_dom_exception.js:116:20)
    at DOMExceptionNetworkError (ext:runtime_main/js/99_main.js:391:12)
    at ext:core/00_infra.js:200:34
    at eventLoopTick (ext:core/01_core.js:59:7)
error: Uncaught (in promise) NetworkError: failed to connect to WebSocket: 不知道这样的主机。 (os error 11001)

curl -I -v localhost:9000 -H host:www.baidu.com
*   Trying [::1]:9000...
*   Trying 127.0.0.1:9000...
* Connected to localhost (127.0.0.1) port 9000
> HEAD / HTTP/1.1
> Host:www.baidu.com
> User-Agent: curl/8.4.0
> Accept: */*
>
* Empty reply from server
* Closing connection
curl: (52) Empty reply from server

[kt3k]

It looks like you also need to await ws.closed to avoid uncaught error:

 const listener = Deno.listen({ port: 9000, transport: "tcp" });

 try {
    for await (const conn of listener) {
        (async () => {
            const ws = new WebSocketStream("ws://loca99999999999lhost:8000", {
                headers: {
                    "x-Protocol": "Transmission Control",
                    "X-Destination-Address": "www.ba99999999999idu.com",
                    "X-Destination-Port": "80",
                },
            });
            // console.log(ws);
            try {
                const webConn = await ws.opened; //.catch(console.error);
                // console.log(webConn);
                conn.readable.pipeTo(webConn.writable).catch(function (e) {
                    try {
                        ws.close();
                        conn.close();
                    } catch (e) {
                        console.error(e);
                    }

                    return console.error(e);
                });
                webConn.readable.pipeTo(conn.writable).catch(function (e) {
                    try {
                        ws.close();
                        conn.close();
                    } catch (e) {
                        console.error(e);
                    }
                    return console.error(e);
                });
            } catch (error) {
                console.error(error);
                try {
                    ws.close();
                    conn.close();
+                   await ws.closed;
                } catch (e) {
                    console.error(e);
                }
            }
        })().catch(console.error);
    }
 } catch (error) {
    console.error(error);
 }

[masx200]

While this can be solved, can we design a better WebSocketStream api?
It's too hard to use

[masx200]

export class WebSocketStream {
    public socket: WebSocket;
    public readable: ReadableStream<Uint8Array>;
    public writable: WritableStream<Uint8Array>;

    constructor(socket: WebSocket) {
        this.socket = socket;
        this.readable = new ReadableStream({
            start(controller) {
                socket.onmessage = function ({ data }) {
                    // console.log(data);
                    return controller.enqueue(new Uint8Array(data));
                };
                socket.onerror = (e) => controller.error(e);
                socket.onclose = (/* e */) => controller.close(/* e */);
            },
            cancel(/* reason */) {
                socket.close();
            },
        });
        this.writable = new WritableStream({
            start(controller) {
                socket.onerror = (e) => controller.error(e);
            },
            write(chunk) {
                // console.log(chunk);
                socket.send(chunk);
            },
            close() {
                socket.close();
            },
            abort(e) {
                console.error(e);
                socket.close();
            },
        });
    }
}

[kt3k]

WebSocketStream is designed based on Web Standard proposal whatwg/websockets#48 It's not a good idea to design it in our own way.

ref: #8831

[kt3k]

Closing as the original issue is solved and nothing is actionable further.

While this can be solved, can we design a better WebSocketStream api?
It's too hard to use

You are encouraged to create 3rd party module to address those pain points