return error rather than panic when merging socket during shutdown

common/client-libs/gateway-client/src/client/mod.rs

@@ -201,7 +201,7 @@ impl<C, St> GatewayClient<C, St> {
     #[cfg(not(target_arch = "wasm32"))]
     pub async fn establish_connection(&mut self) -> Result<(), GatewayClientError> {
         debug!(
-            "Attemting to establish connection to gateway at: {}",
+            "Attempting to establish connection to gateway at: {}",
             self.gateway_address
         );
         let (ws_stream, _) = connect_async(

common/client-libs/gateway-client/src/socket_state.rs

@@ -337,7 +337,7 @@ impl PartiallyDelegatedHandle {
         // check if the split stream didn't error out
         let receive_res = stream_receiver
             .try_recv()
-            .expect("stream sender was somehow dropped without sending anything!");
+            .map_err(|_| GatewayClientError::ConnectionAbruptlyClosed)?;
 
         if let Some(res) = receive_res {
             let _res = res?;