rust_socketio example implementation panicked at EngineIO Error

Question

So I am trying to implement socket communication between a node server and rust client. I am however stuck. No matter what I try, I get the error:

Error: String( "EngineIO Error", ) thread '' panicked at 'EngineIO Error'

I do however receive the connected console.log in the node server, anyone have an idea?

Client code in rust

use rust_socketio::{Client, ClientBuilder, Payload};
use serde_json::json;
use std::time::Duration;

fn main() {
    // define a callback which is called when a payload is received
    // this callback gets the payload as well as an instance of the
    // socket to communicate with the server
    let callback = |payload: Payload, socket: Client| {
        match payload {
            Payload::String(str) => println!("Received: {}", str),
            Payload::Binary(bin_data) => println!("Received bytes: {:#?}", bin_data),
        }
        socket
            .emit("test", json!({"got ack": true}))
            .expect("Server unreachable")
    };

    // get a socket that is connected to the admin namespace
    let socket = ClientBuilder::new("http://localhost:4122")
        .namespace("/admin")
        .on("test", callback)
        .on("error", |err, _| eprintln!("Error: {:#?}", err))
        .connect()
        .expect("Connection failed");

    // emit to the "foo" event
    let json_payload = json!({"token": 123});
    socket
        .emit("foo", json_payload)
        .expect("Server unreachable");

    // define a callback, that's executed when the ack got acked
    let ack_callback = |message: Payload, _| {
        println!("Yehaa! My ack got acked?");
        println!("Ack data: {:#?}", message);
    };

    let json_payload = json!({"myAckData": 123});
    // emit with an ack

    socket
        .emit_with_ack("test", json_payload, Duration::from_secs(2), ack_callback)
        .expect("Server unreachable");

    socket.disconnect().expect("Disconnect failed")
}

Server code node

const app = require('express')();
const http = require('http').Server(app);
const io = require('socket.io')(http);
const port = process.env.PORT || 4122;

app.get('/', (req, res) => {
  res.sendFile(__dirname + '/public/index.html');
});


io.of("/admin").on("connection", (socket) => {
    console.log('connected')
    socket.emit('test','jd')

    socket.on("admin:foo", () => {
        console.log()
        socket.emit('test','jd')
        console.log('test')
    });
  });

http.listen(port, () => {
  console.log(`Socket.IO server running at http://localhost:${port}/`);
});

Answer 1

For socket.io ,you should know it is asynchronous, the event may be not occured before socket.disconnect() you can add loop simply for test like this

use rust_socketio::{Client, ClientBuilder, Payload};
use serde_json::json;
use std::time::Duration;

fn main() {
    // define a callback which is called when a payload is received
    // this callback gets the payload as well as an instance of the
    // socket to communicate with the server
    let callback = |payload: Payload, socket: Client| {
        match payload {
            Payload::String(str) => println!("Received: {}", str),
            Payload::Binary(bin_data) => println!("Received bytes: {:#?}", bin_data),
        }
        socket
            .emit("test", json!({"got ack": true}))
            .expect("Server unreachable")
    };

    // get a socket that is connected to the admin namespace
    let socket = ClientBuilder::new("http://localhost:4122")
        .namespace("/admin")
        .on("test", callback)
        .on("error", |err, _| eprintln!("Error: {:#?}", err))
        .connect()
        .expect("Connection failed");

    // emit to the "foo" event
    let json_payload = json!({"token": 123});
    socket
        .emit("foo", json_payload)
        .expect("Server unreachable");

    // define a callback, that's executed when the ack got acked
    let ack_callback = |message: Payload, _| {
        println!("Yehaa! My ack got acked?");
        println!("Ack data: {:#?}", message);
    };

    let json_payload = json!({"myAckData": 123});
    // emit with an ack

    socket
        .emit_with_ack("test", json_payload, Duration::from_secs(2), ack_callback)
        .expect("Server unreachable");

    loop {

    }
    //socket.disconnect().expect("Disconnect failed")
}

For Server code node, the event name for admin:foo should be foo, and the event for test was not added, you should change the code like this for test

const app = require('express')();
const http = require('http').Server(app);
const io = require('socket.io')(http);
const port = process.env.PORT || 4122;

app.get('/', (req, res) => {
  res.sendFile(__dirname + '/public/index.html');
});


io.of("/admin").on("connection", (socket) => {
    console.log('connected')
    socket.emit('test','jd')

    socket.on("foo", (...args) => {
        console.log(args)
        socket.emit('test','jd')
        console.log('test====')
    });

    socket.on("test", (data,ack) => {
        console.log(ack)
      if (ack) {
        ack(data);
      }
    });

  });

http.listen(port, () => {
  console.log(`Socket.IO server running at http://localhost:${port}/`);
});