Polling and Websocket have different effect in event callback #793

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1. NeatGuyCoding

   added

   bug

   on Nov 18, 2025
2. sanjomo commented on Nov 19, 2025

   

   sanjomo

   on Nov 19, 2025

   Last edited by sanjomo

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   @darrachequesne @nkzawa
3. darrachequesne commented on Nov 20, 2025

   

   darrachequesne

   on Nov 20, 2025

   Member

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   @sanjomo in your screenshot, the events are different ("Y-Solowarm" for HTTP long-polling, "Ronstring" for WebSocket), could it explain your issue?

   Repro:

   • server

   import { Server } from "socket.io";
   
   const port = process.env.PORT || 3000;
   const io = new Server();
   
   setInterval(() => {
     io.emit("echo", {
       a: new Date(),
       b: 1
     });
   }, 1000);
   
   io.listen(port);

   • client:

   public class Fiddle {
   
       public static void main(String[] argz) throws Exception {
           IO.Options options = new IO.Options();
           options.transports = new String[] {"polling"};
           // options.transports = new String[] {"websocket"};
   
           Socket socket = IO.socket(URI.create("http://localhost:3000"), options);
   
           socket.on("echo", (args) -> {
               System.out.printf("echo: %s\n", args);
           });
   
           socket.connect();
       }
   }

   Both transports output:

   echo: {"a":"2025-11-20T10:28:44.396Z","b":1}
   echo: {"a":"2025-11-20T10:28:45.397Z","b":1}
   echo: {"a":"2025-11-20T10:28:46.397Z","b":1}
   echo: {"a":"2025-11-20T10:28:47.397Z","b":1}
   echo: {"a":"2025-11-20T10:28:48.398Z","b":1}
   ...
   
4. NeatGuyCoding commented on Nov 20, 2025

   

   NeatGuyCoding

   on Nov 20, 2025

   Author

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   @darrachequesne kindly refer to: https://github.com/socketio4j/netty-socketio/blob/main/netty-socketio-core/src/test/java/com/socketio4j/socketio/integration/RoomBroadcastTest.java

   which can reproduce the issue