socketio_typescript_server_with_typed_event_interfaces.ts

1import { createServer } from "http";
2import { Server } from "socket.io";
3
4interface ServerToClientEvents {
5  noArg: () => void;
6  basicEmit: (a: number, b: string, c: Buffer) => void;
7  withAck: (d: string, callback: (e: number) => void) => void;
8}
9
10interface ClientToServerEvents {
11  hello: () => void;
12}
13
14interface InterServerEvents {
15  ping: () => void;
16}
17
18interface SocketData {
19  name: string;
20  age: number;
21}
22
23const httpServer = createServer();
24const io = new Server<
25  ClientToServerEvents,
26  ServerToClientEvents,
27  InterServerEvents,
28  SocketData
29>(httpServer, {
30  // options
31});
32
33io.on("connection", (socket) => {
34  console.log("a user connected");
35  
36  socket.on("hello", () => {
37    console.log("hello received");
38  });
39});
40
41httpServer.listen(3000, () => {
42  console.log("server running at http://localhost:3000");
43});