Fix EventBroadcaster change to keep original behavior

Author: roekatz

fastapi_websocket_pubsub/event_broadcaster.py

@@ -222,9 +222,6 @@ async def __aenter__(self):
         return await self._context_manager.__aenter__()
 
     async def __aexit__(self, exc_type, exc, tb):
-        if self.listening_broadcast_channel is not None:
-            await self.listening_broadcast_channel.disconnect()
-            self.listening_broadcast_channel = None
         await self._context_manager.__aexit__(exc_type, exc, tb)
 
     async def start_reader_task(self):
@@ -268,40 +265,45 @@ async def __read_notifications__(self):
         read incoming broadcasts and posting them to the intreal notifier
         """
         logger.debug("Starting broadcaster listener")
-        # Subscribe to our channel
-        async with self.listening_broadcast_channel.subscribe(
-            channel=self._channel
-        ) as subscriber:
-            async for event in subscriber:
-                try:
-                    notification = BroadcastNotification.parse_raw(event.message)
-                    # Avoid re-publishing our own broadcasts
-                    if notification.notifier_id != self._id:
-                        logger.debug(
-                            "Handling incoming broadcast event: {}".format(
-                                {
-                                    "topics": notification.topics,
-                                    "src": notification.notifier_id,
-                                }
+        try:
+            # Subscribe to our channel
+            async with self.listening_broadcast_channel.subscribe(
+                channel=self._channel
+            ) as subscriber:
+                async for event in subscriber:
+                    try:
+                        notification = BroadcastNotification.parse_raw(event.message)
+                        # Avoid re-publishing our own broadcasts
+                        if notification.notifier_id != self._id:
+                            logger.debug(
+                                "Handling incoming broadcast event: {}".format(
+                                    {
+                                        "topics": notification.topics,
+                                        "src": notification.notifier_id,
+                                    }
+                                )
                             )
-                        )
-                        # Notify subscribers of message received from broadcast
-                        task = asyncio.create_task(
-                            self._notifier.notify(
-                                notification.topics,
-                                notification.data,
-                                notifier_id=self._id,
+                            # Notify subscribers of message received from broadcast
+                            task = asyncio.create_task(
+                                self._notifier.notify(
+                                    notification.topics,
+                                    notification.data,
+                                    notifier_id=self._id,
+                                )
                             )
-                        )
 
-                        self._tasks.add(task)
+                            self._tasks.add(task)
 
-                        def cleanup(task):
-                            self._tasks.remove(task)
+                            def cleanup(task):
+                                self._tasks.remove(task)
 
-                        task.add_done_callback(cleanup)
-                except:
-                    logger.exception("Failed handling incoming broadcast")
-            logger.info(
-                "No more events to read from subscriber (underlying connection closed)"
-            )
+                            task.add_done_callback(cleanup)
+                    except:
+                        logger.exception("Failed handling incoming broadcast")
+                logger.info(
+                    "No more events to read from subscriber (underlying connection closed)"
+                )
+        finally:
+            if self.listening_broadcast_channel is not None:
+                await self.listening_broadcast_channel.disconnect()
+                self.listening_broadcast_channel = None