socketio_typescript_server_with_strongly_typed_events.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();
24
25const io = new Server<
26  ClientToServerEvents,
27  ServerToClientEvents,
28  InterServerEvents,
29  SocketData
30>(httpServer, {
31  // options
32});
33
34io.on("connection", (socket) => {
35  console.log("a user connected");
36  
37  socket.on("hello", () => {
38    console.log("hello received");
39  });
40});
41
42httpServer.listen(3000, () => {
43  console.log("Server is running on http://localhost:3000");
44});