Return errors from Worker::run().

proto/src/core/worker.rs

@@ -28,7 +28,7 @@ async fn forward_incoming<ReadFrame: ValueDecode + Debug>(
   incoming_tx: mpsc::Sender<ReadFrame>,
 ) -> Result<(), WorkerError> {
   while let Some(frame) = reader.read().await.map_err(WorkerError::ReadError)? {
-    debug!("Channel: received frame: {:?}", frame);
+    debug!("Received frame: {:?}", frame);
 
     if let Err(_) = incoming_tx.send(frame).await {
       return Err(WorkerError::IncomingChannelClosed);
@@ -44,7 +44,7 @@ async fn forward_outgoing<WriteFrame: ValueEncode + Debug>(
   mut writer: FrameWriter<WriteFrame, OwnedWriteHalf>,
 ) -> Result<(), WorkerError> {
   while let Some(frame) = outgoing_rx.recv().await {
-    debug!("Channel: sending frame: {:?}", frame);
+    debug!("Sending frame: {:?}", frame);
     writer
       .write(&frame)
       .await
@@ -86,12 +86,8 @@ where
 
   async fn run(self) -> Result<(), WorkerError> {
     tokio::select! {
-      result = forward_incoming(self.reader, self.incoming_tx) => {
-        debug!("{:?}", result);
-      },
-      result = forward_outgoing(self.outgoing_rx, self.writer) => {
-        debug!("{:?}", result);
-      },
+      result = forward_incoming(self.reader, self.incoming_tx) => result?,
+      result = forward_outgoing(self.outgoing_rx, self.writer) => result?,
     };
 
     Ok(())
@@ -113,6 +109,8 @@ mod tests {
     let _ = env_logger::builder().is_test(true).try_init();
   }
 
+  // TODO: test for all 3 error conditions.
+
   #[tokio::test]
   async fn forwards_incoming_frames() {
     init();