Function read_subscription_request 

pub async fn read_subscription_request(
    socket: &mut WebSocket,
) -> Result<SubscriptionRequest, ServerError>

Read the first subscription frame from an accepted WebSocket.

Ping/pong frames are ignored while waiting; a close, socket error, or malformed frame is a decode failure the caller reports as one terminal error frame.

Errors

Returns ServerError::Wire (invalid_input) when the socket closes before a request arrives or the request cannot be decoded.