improve signalR unsubscribe

src/services/signalr/index.ts

@@ -48,6 +48,21 @@ type handlerFunction = (...args: any[]) => void;
 
 type cleanFunction = (...args: any[]) => void;
 
+const MakeUnsubscribeFunction = (
+  connection: HubConnection, 
+  methodName: string, 
+  groupName: (string|null)):cleanFunction => {
+  return async() => {
+    if(connection.state === HubConnectionState.Connected)
+    {
+      if(groupName)
+        await connection.send('RemoveFromGroup', groupName)
+      connection.off(methodName)
+    }
+    connection.stop()
+  }
+}
+
 /** Subscribe on some SignalR method (topic).
  * @example useEffect(() => Subscribe('methodName', `${id}`, handleNewData), [id]);
  * @param {string} methodName name of the method
@@ -66,12 +81,7 @@ const Subscribe = (
       connection.on(methodName, handler)
   })
   
-  if(groupName)
-    return () => {
-      Connections[hubUrl].send('RemoveFromGroup', groupName)
-      .finally(()=>Connections[hubUrl].off(methodName))
-    }
-  return () => Connections[hubUrl].off(methodName)  
+  return MakeUnsubscribeFunction(Connections[hubUrl],methodName,groupName)
 }
 
 /** Invokes some SignalR method.