add retuning 'int' with redis publish

broadcaster/_backends/redis.py

@@ -28,8 +28,8 @@ async def subscribe(self, channel: str) -> None:
     async def unsubscribe(self, channel: str) -> None:
         await self._subscriber.unsubscribe([channel])
 
-    async def publish(self, channel: str, message: typing.Any) -> None:
-        await self._pub_conn.publish(channel, message)
+    async def publish(self, channel: str, message: typing.Any) -> int:
+        return await self._pub_conn.publish(channel, message)
 
     async def next_published(self) -> Event:
         message = await self._subscriber.next_published()

broadcaster/_base.py

@@ -75,8 +75,8 @@ async def _listener(self) -> None:
             for queue in list(self._subscribers.get(event.channel, [])):
                 await queue.put(event)
 
-    async def publish(self, channel: str, message: Any) -> None:
-        await self._backend.publish(channel, message)
+    async def publish(self, channel: str, message: Any) -> Optional[int]:
+        return await self._backend.publish(channel, message)
 
     @asynccontextmanager
     async def subscribe(self, channel: str) -> AsyncIterator["Subscriber"]: