Implement socket.io v4

.env.development

@@ -1 +1,2 @@
-PORT=3002
+PORT=3002
+CORS_ORIGIN='meet.jit.si'

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:16.17-slim
+FROM node:22-bookworm-slim
 
 WORKDIR /excalidraw-backend
 
@@ -9,4 +9,4 @@ RUN npm run build
 EXPOSE 80
 EXPOSE 9090
 
-CMD ["npm", "start"]
+CMD ["npm", "start"]

package.json

@@ -9,22 +9,22 @@
     },
     "private": true,
     "engines": {
-        "node": ">=14.0.0",
-        "npm": ">=7.0.0"
+        "node": ">=20.0.0",
+        "npm": ">=10.0.0"
     },
     "dependencies": {
-        "@types/debug": "4.1.5",
-        "@types/express": "4.17.11",
-        "@types/node": "14.14.31",
-        "@types/socket.io": "2.1.4",
+        "@types/debug": "4.1.10",
+        "@types/express": "4.17.20",
+        "@types/ms": "0.7.33",
+        "@types/node": "20.8.7",
         "cross-env": "^7.0.3",
-        "debug": "4.3.1",
-        "dotenv": "^10.0.0",
-        "express": "4.17.1",
-        "socket.io": "^2.5.0",
+        "debug": "4.3.4",
+        "dotenv": "^16.0.0",
+        "express": "^4.19.2",
+        "socket.io": "^4.7.2",
         "socket.io-prometheus-metrics": "^1.0.6",
-        "ts-node-dev": "^1.1.8",
-        "typescript": "4.2.3"
+        "ts-node-dev": "^2.0.0",
+        "typescript": "5.2.2"
     },
     "license": "MIT",
     "scripts": {
@@ -37,16 +37,15 @@
     },
     "devDependencies": {
         "@jitsi/eslint-config": "^4.1.0",
-        "@types/dotenv": "^8.2.0",
-        "@typescript-eslint/eslint-plugin": "5.30.5",
-        "@typescript-eslint/parser": "5.30.4",
-        "eslint": "8.1.0",
-        "eslint-plugin-import": "2.25.2",
-        "eslint-plugin-jsdoc": "37.0.3",
-        "eslint-plugin-typescript-sort-keys": "^2.1.0"
+        "@typescript-eslint/eslint-plugin": "6.8.0",
+        "@typescript-eslint/parser": "6.8.0",
+        "eslint": "^8.1.0",
+        "eslint-plugin-import": "2.28.1",
+        "eslint-plugin-jsdoc": "46.8.2",
+        "eslint-plugin-typescript-sort-keys": "^3.1.0"
     },
     "optionalDependencies": {
         "bufferutil": "^4.0.6",
-        "utf-8-validate": "^5.0.9"
+        "utf-8-validate": "^6.0.3"
     }
 }

src/index.ts

@@ -2,8 +2,8 @@ import debug from 'debug';
 import dotenv from 'dotenv';
 import express from 'express';
 import http from 'http';
-import socketIO, { Socket } from 'socket.io';
-import * as prometheus from 'socket.io-prometheus-metrics';
+import { Socket, Server } from 'socket.io';
+//import * as prometheus from 'socket.io-prometheus-metrics';
 
 const serverDebug = debug('server');
 
@@ -28,25 +28,22 @@ server.listen(port, () => {
     serverDebug(`listening on port: ${port}`);
 });
 
-const io = socketIO(server, {
-    handlePreflightRequest: (req, res) => {
-        const headers = {
-            'Access-Control-Allow-Headers': 'Content-Type, Authorization',
-            'Access-Control-Allow-Origin': req.header?.origin ?? 'https://meet.jit.si',
-            'Access-Control-Allow-Credentials': true
-        };
+const corsOptions = {
+    origin: process.env.CORS_ORIGIN,
+    methods: [ 'GET', 'POST' ]
+};
 
-        res.writeHead(200, headers);
-        res.end();
-    },
+const io = new Server(server, {
+    allowEIO3: true,
+    cors: corsOptions,
     maxHttpBufferSize: 20e6,
     pingTimeout: 60000
 });
 
 // listens on host:9090/metrics
-prometheus.metrics(io, {
-    collectDefaultMetrics: true
-});
+// prometheus.metrics(io, {
+//    collectDefaultMetrics: true
+// });
 
 io.on('connection', socket => {
     serverDebug(`connection established! ${socket.conn.request.url}`);
@@ -60,27 +57,27 @@ io.on('connection', socket => {
             users.splice(users.indexOf(socket), 1);
         });
 
-        const clients = Object.keys(io.sockets.adapter.rooms[roomID].sockets);
+        const clients = Object.keys(io.sockets.adapter.rooms.get(roomID)?.keys() ?? new Set<string>());
 
         if (clients.length > userLimit) {
             clients.forEach((clientKey: string) => {
-                const clientSocket = io.sockets.connected[clientKey];
+                const clientSocket = io.sockets.sockets.get(clientKey);
 
-                serverDebug(`${clientSocket} has left the ${roomID} room because the user limit was reached.`);
-                clientSocket.leave(roomID);
+                if (clientSocket !== undefined) {
+                    serverDebug(`${clientSocket} has left the ${roomID} room because the user limit was reached.`);
+                    clientSocket.leave(roomID);
+                }
             });
 
             return;
         }
-
-        if (io.sockets.adapter.rooms[roomID].length <= 1) {
+        if (io.sockets.adapter.rooms.get(roomID)?.size ?? 0 <= 1) {
             io.to(`${socket.id}`).emit('first-in-room');
         } else {
             socket.broadcast.to(roomID).emit('new-user', socket.id);
         }
         io.in(roomID).emit(
-            'room-user-change',
-            Object.keys(io.sockets.adapter.rooms[roomID].sockets)
+            'room-user-change', Array.from(io.sockets.adapter.rooms.get(roomID) ?? [])
         );
     });
 
@@ -104,7 +101,7 @@ io.on('connection', socket => {
         const rooms = io.sockets.adapter.rooms;
 
         for (const roomID of Object.keys(socket.rooms)) {
-            const clients = Object.keys(rooms[roomID].sockets).filter(id => id !== socket.id);
+            const clients = Array.from(rooms.get(roomID) ?? []).filter(id => id !== socket.id);
 
             if (roomID !== socket.id) {
                 socket.to(roomID).emit('user has left', socket.id);