chore(release): engine.io-client@6.6.1

Diff: https://github.com/socketio/socket.io/compare/engine.io-client@6.6.0...engine.io-client@6.6.1

.github/workflows/ci-browser.yml

@@ -14,7 +14,7 @@ permissions:
 jobs:
   test-browser:
     runs-on: ubuntu-latest
-    timeout-minutes: 10
+    timeout-minutes: 20
 
     steps:
       - name: Checkout repository

.github/workflows/ci.yml

@@ -44,13 +44,16 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
-      # in order to test our compliance with TypeScript v4.2 (older versions are not tested)
-      - name: Install TypeScript 4.2
-        run: npm i typescript@4.2
-        if: ${{ matrix.node-version == '16' }}
-
       - name: Compile each package
         run: npm run compile --workspaces --if-present
 
       - name: Run tests
         run: npm test --workspaces
+
+      - name: Run tests with uws (engine.io)
+        run: npm run test:uws --workspace=engine.io
+        if: ${{ matrix.node-version == '18' }}
+
+      - name: Run tests with fetch instead of XHR (engine.io-client)
+        run: npm run test:node-fetch --workspace=engine.io-client
+        if: ${{ matrix.node-version == '18' }}

.github/workflows/publish.yml

@@ -6,7 +6,7 @@ on:
   push:
     tags:
       # expected format: <package>@<version> (example: socket.io@1.2.3)
-      - '*@*'
+      - '**@*'
 
 jobs:
   publish:
@@ -28,6 +28,9 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Compile each package
+        run: npm run compile --workspaces --if-present
+
       - name: Publish package
         run: npm publish --workspace=${GITHUB_REF_NAME%@*} --provenance --access public
         env:

CONTRIBUTING.md

@@ -150,3 +150,18 @@ For a specific workspace:
 ```bash
 npm test --workspace=socket.io
 ```
+
+### Generate the changelog
+
+Install the [`conventional-changelog-cli`](https://www.npmjs.com/package/conventional-changelog-cli) package:
+
+```bash
+npm i -g conventional-changelog-cli
+```
+
+Then run:
+
+```bash
+cd packages/engine.io-client
+conventional-changelog -p angular --tag-prefix "engine.io-client@" --commit-path .
+```

examples/cluster-engine-node-cluster/README.md

@@ -0,0 +1,19 @@
+# Example with `@socket.io/cluster-engine` and Node.js cluster
+
+## How to use
+
+```bash
+# run the server
+$ node server.js
+
+# run the client
+$ node client.js
+```
+
+## Explanation
+
+The `server.js` script will create one Socket.IO server per core, each listening on the same port (`3000`).
+
+With the default engine (provided by the `engine.io` package), sticky sessions would be required, so that each HTTP request of the same Engine.IO session reaches the same worker.
+
+The `NodeClusterEngine` is a custom engine which takes care of the synchronization between the servers by using [the IPC channel](https://nodejs.org/api/cluster.html#workersendmessage-sendhandle-options-callback) and removes the need for sticky sessions when scaling horizontally.

examples/cluster-engine-node-cluster/client.js

@@ -0,0 +1,26 @@
+import { io } from "socket.io-client";
+
+const CLIENTS_COUNT = 3;
+
+for (let i = 0; i < CLIENTS_COUNT; i++) {
+  const socket = io("ws://localhost:3000/", {
+    // transports: ["polling"],
+    // transports: ["websocket"],
+  });
+
+  socket.on("connect", () => {
+    console.log(`connected as ${socket.id}`);
+  });
+
+  socket.on("disconnect", (reason) => {
+    console.log(`disconnected due to ${reason}`);
+  });
+
+  socket.on("hello", (socketId, workerId) => {
+    console.log(`received "hello" from ${socketId} (worker: ${workerId})`);
+  });
+
+  setInterval(() => {
+    socket.emit("hello");
+  }, 2000);
+}

examples/cluster-engine-node-cluster/package.json

@@ -0,0 +1,12 @@
+{
+  "private": true,
+  "name": "cluster-engine-node-cluster",
+  "version": "0.0.1",
+  "type": "module",
+  "dependencies": {
+    "@socket.io/cluster-adapter": "^0.2.2",
+    "@socket.io/cluster-engine": "^0.1.0",
+    "socket.io": "^4.7.5",
+    "socket.io-client": "^4.7.5"
+  }
+}

examples/cluster-engine-node-cluster/server.js

@@ -0,0 +1,63 @@
+import cluster from "node:cluster";
+import process from "node:process";
+import { availableParallelism } from "node:os";
+import {
+  setupPrimary as setupPrimaryEngine,
+  NodeClusterEngine,
+} from "@socket.io/cluster-engine";
+import {
+  setupPrimary as setupPrimaryAdapter,
+  createAdapter,
+} from "@socket.io/cluster-adapter";
+import { createServer } from "node:http";
+import { Server } from "socket.io";
+
+if (cluster.isPrimary) {
+  console.log(`Primary ${process.pid} is running`);
+
+  const numCPUs = availableParallelism();
+
+  // fork workers
+  for (let i = 0; i < numCPUs; i++) {
+    cluster.fork();
+  }
+
+  setupPrimaryEngine();
+  setupPrimaryAdapter();
+
+  // needed for packets containing Buffer objects (you can ignore it if you only send plaintext objects)
+  cluster.setupPrimary({
+    serialization: "advanced",
+  });
+
+  cluster.on("exit", (worker, code, signal) => {
+    console.log(`worker ${worker.process.pid} died`);
+  });
+} else {
+  const httpServer = createServer((req, res) => {
+    res.writeHead(404).end();
+  });
+
+  const engine = new NodeClusterEngine();
+
+  engine.attach(httpServer, {
+    path: "/socket.io/",
+  });
+
+  const io = new Server({
+    adapter: createAdapter(),
+  });
+
+  io.bind(engine);
+
+  io.on("connection", (socket) => {
+    socket.on("hello", () => {
+      socket.broadcast.emit("hello", socket.id, process.pid);
+    });
+  });
+
+  // workers will share the same port
+  httpServer.listen(3000);
+
+  console.log(`Worker ${process.pid} started`);
+}

examples/cluster-engine-redis/README.md

@@ -0,0 +1,22 @@
+# Example with `@socket.io/cluster-engine` and Redis
+
+## How to use
+
+```bash
+# start the redis server
+$ docker compose up -d
+
+# run the server
+$ node server.js
+
+# run the client
+$ node client.js
+```
+
+## Explanation
+
+The `server.js` script will create 3 Socket.IO servers, each listening on a distinct port (`3001`, `3002` and `3003`), and a proxy server listening on port `3000` which randomly redirects to one of those servers.
+
+With the default engine (provided by the `engine.io` package), sticky sessions would be required, so that each HTTP request of the same Engine.IO session reaches the same server.
+
+The `RedisEngine` is a custom engine which takes care of the synchronization between the servers by using [Redis pub/sub](https://redis.io/docs/latest/develop/interact/pubsub/) and removes the need for sticky sessions when scaling horizontally.

examples/cluster-engine-redis/client.js

@@ -0,0 +1,26 @@
+import { io } from "socket.io-client";
+
+const CLIENTS_COUNT = 3;
+
+for (let i = 0; i < CLIENTS_COUNT; i++) {
+  const socket = io("ws://localhost:3000/", {
+    // transports: ["polling"],
+    // transports: ["websocket"],
+  });
+
+  socket.on("connect", () => {
+    console.log(`connected as ${socket.id}`);
+  });
+
+  socket.on("disconnect", (reason) => {
+    console.log(`disconnected due to ${reason}`);
+  });
+
+  socket.on("hello", (socketId, workerId) => {
+    console.log(`received "hello" from ${socketId} (worker: ${workerId})`);
+  });
+
+  setInterval(() => {
+    socket.emit("hello");
+  }, 2000);
+}

examples/cluster-engine-redis/compose.yaml

@@ -0,0 +1,5 @@
+services:
+  redis:
+    image: redis:7
+    ports:
+      - "6379:6379"

examples/cluster-engine-redis/package.json

@@ -0,0 +1,14 @@
+{
+  "private": true,
+  "name": "cluster-engine-redis",
+  "version": "0.0.1",
+  "type": "module",
+  "dependencies": {
+    "@socket.io/cluster-engine": "^0.1.0",
+    "@socket.io/redis-adapter": "^8.3.0",
+    "http-proxy": "^1.18.1",
+    "redis": "^4.6.15",
+    "socket.io": "^4.7.5",
+    "socket.io-client": "^4.7.5"
+  }
+}

examples/cluster-engine-redis/server.js

@@ -0,0 +1,65 @@
+import { RedisEngine } from "@socket.io/cluster-engine";
+import { createServer } from "node:http";
+import { createClient } from "redis";
+import { Server } from "socket.io";
+import { createAdapter } from "@socket.io/redis-adapter";
+import proxyModule from "http-proxy";
+
+const { createProxyServer } = proxyModule;
+
+async function initServer(port) {
+  const httpServer = createServer((req, res) => {
+    res.writeHead(404).end();
+  });
+
+  const pubClient = createClient();
+  const subClient = pubClient.duplicate();
+
+  await Promise.all([pubClient.connect(), subClient.connect()]);
+
+  const engine = new RedisEngine(pubClient, subClient);
+
+  engine.attach(httpServer, {
+    path: "/socket.io/",
+  });
+
+  const io = new Server({
+    adapter: createAdapter(pubClient, subClient),
+  });
+
+  io.bind(engine);
+
+  io.on("connection", (socket) => {
+    socket.on("hello", () => {
+      socket.broadcast.emit("hello", socket.id, port);
+    });
+  });
+
+  httpServer.listen(port);
+}
+
+function initProxy() {
+  const proxy = createProxyServer();
+
+  function randomTarget() {
+    return [
+      "http://localhost:3001",
+      "http://localhost:3002",
+      "http://localhost:3003",
+    ][Math.floor(Math.random() * 3)];
+  }
+
+  const httpServer = createServer((req, res) => {
+    proxy.web(req, res, { target: randomTarget() });
+  });
+
+  httpServer.on("upgrade", function (req, socket, head) {
+    proxy.ws(req, socket, head, { target: randomTarget() });
+  });
+
+  httpServer.listen(3000);
+}
+
+await Promise.all([initServer(3001), initServer(3002), initServer(3003)]);
+
+initProxy();

examples/nestjs-example/.eslintrc.js

@@ -0,0 +1,25 @@
+module.exports = {
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: 'tsconfig.json',
+    tsconfigRootDir: __dirname,
+    sourceType: 'module',
+  },
+  plugins: ['@typescript-eslint/eslint-plugin'],
+  extends: [
+    'plugin:@typescript-eslint/recommended',
+    'plugin:prettier/recommended',
+  ],
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  ignorePatterns: ['.eslintrc.js'],
+  rules: {
+    '@typescript-eslint/interface-name-prefix': 'off',
+    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/explicit-module-boundary-types': 'off',
+    '@typescript-eslint/no-explicit-any': 'off',
+  },
+};

examples/nestjs-example/.gitignore

@@ -0,0 +1,56 @@
+# compiled output
+/dist
+/node_modules
+/build
+
+# Logs
+logs
+*.log
+npm-debug.log*
+pnpm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# temp directory
+.temp
+.tmp
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json

examples/nestjs-example/.prettierrc

@@ -0,0 +1,4 @@
+{
+  "singleQuote": true,
+  "trailingComma": "all"
+}

examples/nestjs-example/README.md

@@ -0,0 +1,73 @@
+<p align="center">
+  <a href="http://nestjs.com/" target="blank"><img src="https://nestjs.com/img/logo-small.svg" width="200" alt="Nest Logo" /></a>
+</p>
+
+[circleci-image]: https://img.shields.io/circleci/build/github/nestjs/nest/master?token=abc123def456
+[circleci-url]: https://circleci.com/gh/nestjs/nest
+
+  <p align="center">A progressive <a href="http://nodejs.org" target="_blank">Node.js</a> framework for building efficient and scalable server-side applications.</p>
+    <p align="center">
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/v/@nestjs/core.svg" alt="NPM Version" /></a>
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/l/@nestjs/core.svg" alt="Package License" /></a>
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/dm/@nestjs/common.svg" alt="NPM Downloads" /></a>
+<a href="https://circleci.com/gh/nestjs/nest" target="_blank"><img src="https://img.shields.io/circleci/build/github/nestjs/nest/master" alt="CircleCI" /></a>
+<a href="https://coveralls.io/github/nestjs/nest?branch=master" target="_blank"><img src="https://coveralls.io/repos/github/nestjs/nest/badge.svg?branch=master#9" alt="Coverage" /></a>
+<a href="https://discord.gg/G7Qnnhy" target="_blank"><img src="https://img.shields.io/badge/discord-online-brightgreen.svg" alt="Discord"/></a>
+<a href="https://opencollective.com/nest#backer" target="_blank"><img src="https://opencollective.com/nest/backers/badge.svg" alt="Backers on Open Collective" /></a>
+<a href="https://opencollective.com/nest#sponsor" target="_blank"><img src="https://opencollective.com/nest/sponsors/badge.svg" alt="Sponsors on Open Collective" /></a>
+  <a href="https://paypal.me/kamilmysliwiec" target="_blank"><img src="https://img.shields.io/badge/Donate-PayPal-ff3f59.svg"/></a>
+    <a href="https://opencollective.com/nest#sponsor"  target="_blank"><img src="https://img.shields.io/badge/Support%20us-Open%20Collective-41B883.svg" alt="Support us"></a>
+  <a href="https://twitter.com/nestframework" target="_blank"><img src="https://img.shields.io/twitter/follow/nestframework.svg?style=social&label=Follow"></a>
+</p>
+  <!--[![Backers on Open Collective](https://opencollective.com/nest/backers/badge.svg)](https://opencollective.com/nest#backer)
+  [![Sponsors on Open Collective](https://opencollective.com/nest/sponsors/badge.svg)](https://opencollective.com/nest#sponsor)-->
+
+## Description
+
+[Nest](https://github.com/nestjs/nest) framework TypeScript starter repository.
+
+## Installation
+
+```bash
+$ npm install
+```
+
+## Running the app
+
+```bash
+# development
+$ npm run start
+
+# watch mode
+$ npm run start:dev
+
+# production mode
+$ npm run start:prod
+```
+
+## Test
+
+```bash
+# unit tests
+$ npm run test
+
+# e2e tests
+$ npm run test:e2e
+
+# test coverage
+$ npm run test:cov
+```
+
+## Support
+
+Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support by the amazing backers. If you'd like to join them, please [read more here](https://docs.nestjs.com/support).
+
+## Stay in touch
+
+- Author - [Kamil Myśliwiec](https://kamilmysliwiec.com)
+- Website - [https://nestjs.com](https://nestjs.com/)
+- Twitter - [@nestframework](https://twitter.com/nestframework)
+
+## License
+
+Nest is [MIT licensed](LICENSE).

examples/nestjs-example/nest-cli.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://json.schemastore.org/nest-cli",
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src",
+  "compilerOptions": {
+    "deleteOutDir": true
+  }
+}

examples/nestjs-example/package.json

@@ -0,0 +1,72 @@
+{
+  "name": "nestjs-example",
+  "version": "0.0.1",
+  "description": "",
+  "author": "",
+  "private": true,
+  "license": "UNLICENSED",
+  "scripts": {
+    "build": "nest build",
+    "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
+    "start": "nest start",
+    "start:dev": "nest start --watch",
+    "start:debug": "nest start --debug --watch",
+    "start:prod": "node dist/main",
+    "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "test:cov": "jest --coverage",
+    "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
+    "test:e2e": "jest --config ./test/jest-e2e.json"
+  },
+  "dependencies": {
+    "@nestjs/common": "^10.0.0",
+    "@nestjs/core": "^10.0.0",
+    "@nestjs/platform-express": "^10.0.0",
+    "@nestjs/platform-socket.io": "^10.3.10",
+    "@nestjs/websockets": "^10.3.10",
+    "hbs": "^4.2.0",
+    "reflect-metadata": "^0.2.0",
+    "rxjs": "^7.8.1"
+  },
+  "devDependencies": {
+    "@nestjs/cli": "^10.0.0",
+    "@nestjs/schematics": "^10.0.0",
+    "@nestjs/testing": "^10.0.0",
+    "@types/express": "^4.17.17",
+    "@types/jest": "^29.5.2",
+    "@types/node": "^20.3.1",
+    "@types/supertest": "^6.0.0",
+    "@typescript-eslint/eslint-plugin": "^7.0.0",
+    "@typescript-eslint/parser": "^7.0.0",
+    "eslint": "^8.42.0",
+    "eslint-config-prettier": "^9.0.0",
+    "eslint-plugin-prettier": "^5.0.0",
+    "jest": "^29.5.0",
+    "prettier": "^3.0.0",
+    "source-map-support": "^0.5.21",
+    "supertest": "^7.0.0",
+    "ts-jest": "^29.1.0",
+    "ts-loader": "^9.4.3",
+    "ts-node": "^10.9.1",
+    "tsconfig-paths": "^4.2.0",
+    "typescript": "^5.1.3"
+  },
+  "jest": {
+    "moduleFileExtensions": [
+      "js",
+      "json",
+      "ts"
+    ],
+    "rootDir": "src",
+    "testRegex": ".*\\.spec\\.ts$",
+    "transform": {
+      "^.+\\.(t|j)s$": "ts-jest"
+    },
+    "collectCoverageFrom": [
+      "**/*.(t|j)s"
+    ],
+    "coverageDirectory": "../coverage",
+    "testEnvironment": "node"
+  }
+}

examples/nestjs-example/src/app.controller.spec.ts

@@ -0,0 +1,22 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { AppController } from './app.controller';
+import { AppService } from './app.service';
+
+describe('AppController', () => {
+  let appController: AppController;
+
+  beforeEach(async () => {
+    const app: TestingModule = await Test.createTestingModule({
+      controllers: [AppController],
+      providers: [AppService],
+    }).compile();
+
+    appController = app.get<AppController>(AppController);
+  });
+
+  describe('root', () => {
+    it('should return "Hello World!"', () => {
+      expect(appController.getHello()).toBe('Hello World!');
+    });
+  });
+});

examples/nestjs-example/src/app.controller.ts

@@ -0,0 +1,13 @@
+import { Controller, Get, Render } from '@nestjs/common';
+import { AppService } from './app.service';
+
+@Controller()
+export class AppController {
+  constructor(private readonly appService: AppService) {}
+
+  @Get()
+  @Render('index')
+  root() {
+    return { message: 'Hello world2!' };
+  }
+}

examples/nestjs-example/src/app.module.ts

@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { AppController } from './app.controller';
+import { AppService } from './app.service';
+import { EventsModule } from './events/events.module';
+
+@Module({
+  imports: [EventsModule],
+  controllers: [AppController],
+  providers: [AppService],
+})
+export class AppModule {}

examples/nestjs-example/src/app.service.ts

@@ -0,0 +1,8 @@
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class AppService {
+  getHello(): string {
+    return 'Hello World!';
+  }
+}

examples/nestjs-example/src/events/events.gateway.ts

@@ -0,0 +1,18 @@
+import {
+  MessageBody,
+  SubscribeMessage,
+  WebSocketGateway,
+  WebSocketServer,
+} from '@nestjs/websockets';
+import { Server } from 'socket.io';
+
+@WebSocketGateway({})
+export class EventsGateway {
+  @WebSocketServer()
+  io: Server;
+
+  @SubscribeMessage('hello')
+  handleEvent(@MessageBody() data: string): string {
+    return data.split('').reverse().join('');
+  }
+}

examples/nestjs-example/src/events/events.module.ts

@@ -0,0 +1,7 @@
+import { Module } from '@nestjs/common';
+import { EventsGateway } from './events.gateway';
+
+@Module({
+  providers: [EventsGateway],
+})
+export class EventsModule {}

examples/nestjs-example/src/main.ts

@@ -0,0 +1,15 @@
+import { NestFactory } from '@nestjs/core';
+import { AppModule } from './app.module';
+import { NestExpressApplication } from '@nestjs/platform-express';
+import { join } from 'node:path';
+
+async function bootstrap() {
+  const app = await NestFactory.create<NestExpressApplication>(AppModule);
+
+  app.setBaseViewsDir(join(__dirname, '..', 'views'));
+  app.setViewEngine('hbs');
+
+  await app.listen(3000);
+}
+
+bootstrap();

examples/nestjs-example/test/app.e2e-spec.ts

@@ -0,0 +1,24 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { INestApplication } from '@nestjs/common';
+import * as request from 'supertest';
+import { AppModule } from './../src/app.module';
+
+describe('AppController (e2e)', () => {
+  let app: INestApplication;
+
+  beforeEach(async () => {
+    const moduleFixture: TestingModule = await Test.createTestingModule({
+      imports: [AppModule],
+    }).compile();
+
+    app = moduleFixture.createNestApplication();
+    await app.init();
+  });
+
+  it('/ (GET)', () => {
+    return request(app.getHttpServer())
+      .get('/')
+      .expect(200)
+      .expect('Hello World!');
+  });
+});

examples/nestjs-example/test/jest-e2e.json

@@ -0,0 +1,9 @@
+{
+  "moduleFileExtensions": ["js", "json", "ts"],
+  "rootDir": ".",
+  "testEnvironment": "node",
+  "testRegex": ".e2e-spec.ts$",
+  "transform": {
+    "^.+\\.(t|j)s$": "ts-jest"
+  }
+}

examples/nestjs-example/tsconfig.build.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": ["node_modules", "test", "dist", "**/*spec.ts"]
+}

examples/nestjs-example/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "declaration": true,
+    "removeComments": true,
+    "emitDecoratorMetadata": true,
+    "experimentalDecorators": true,
+    "allowSyntheticDefaultImports": true,
+    "target": "ES2021",
+    "sourceMap": true,
+    "outDir": "./dist",
+    "baseUrl": "./",
+    "incremental": true,
+    "skipLibCheck": true,
+    "strictNullChecks": false,
+    "noImplicitAny": false,
+    "strictBindCallApply": false,
+    "forceConsistentCasingInFileNames": false,
+    "noFallthroughCasesInSwitch": false
+  }
+}

examples/nestjs-example/views/index.hbs

@@ -0,0 +1,47 @@
+
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8" />
+  <title>App</title>
+</head>
+<body>
+  <p>Status: <span id="status"></span></p>
+  <p>Transport: <span id="transport"></span></p>
+  <script src="/socket.io/socket.io.js"></script>
+  <script>
+    const statusSpan = document.getElementById("status");
+    const transportSpan = document.getElementById("transport");
+    const socket = io({
+      // transports: ["polling"],
+      // transports: ["websocket"],
+    });
+
+    statusSpan.innerText = "Disconnected";
+    transportSpan.innerText = "N/A";
+
+    socket.on("connect", () => {
+      statusSpan.innerText = "Connected";
+      transportSpan.innerText = socket.io.engine.transport.name;
+      socket.io.engine.on("upgrade", (transport) => {
+        transportSpan.innerText = transport.name;
+      });
+      console.log(`connect ${socket.id}`);
+
+      socket.emit("hello", "world", (val) => {
+        console.log(`got ${val}`);
+      });
+    });
+
+    socket.on("connect_error", (err) => {
+      console.log(`connect_error due to ${err.message}`);
+    });
+
+    socket.on("disconnect", (reason) => {
+      statusSpan.innerText = "Disconnected";
+      transportSpan.innerText = "N/A";
+      console.log(`disconnect due to ${reason}`);
+    });
+  </script>
+</body>
+</html>

examples/postgres-adapter-example/README.md

@@ -0,0 +1,25 @@
+# Example with `@socket.io/postgres-adapter`
+
+**Table of contents**
+
+<!-- TOC -->
+  * [How to use](#how-to-use)
+  * [Documentation](#documentation)
+<!-- TOC -->
+
+## How to use
+
+```bash
+# start the postgres server
+$ docker compose up -d
+
+# run the cluster
+$ node cluster.js
+
+# run the client
+$ node client.js
+```
+
+## Documentation
+
+The documentation can be found here: https://socket.io/docs/v4/postgres-adapter/

examples/postgres-adapter-example/client.js

@@ -0,0 +1,31 @@
+import { io } from "socket.io-client";
+
+const CLIENTS_COUNT = 3;
+const PORTS = [3000, 3001, 3002];
+
+for (let i = 0; i < CLIENTS_COUNT; i++) {
+  const socket = io(`ws://localhost:${PORTS[i % 3]}`, {
+    // transports: ["polling"],
+    // transports: ["websocket"],
+  });
+
+  socket.on("connect", () => {
+    console.log(`connected as ${socket.id}`);
+  });
+
+  socket.on("connect_error", () => {
+    console.log(`connect_error`);
+  });
+
+  socket.on("disconnect", (reason) => {
+    console.log(`disconnected due to ${reason}`);
+  });
+
+  socket.on("hello", (socketId, pid) => {
+    console.log(`received "hello" from ${socketId} (process: ${pid})`);
+  });
+
+  setInterval(() => {
+    socket.emit("hello");
+  }, 2000);
+}

examples/postgres-adapter-example/cluster.js

@@ -0,0 +1,13 @@
+import cluster from 'node:cluster';
+
+const SERVERS_COUNT = 3;
+
+cluster.setupPrimary({
+  exec: 'server.js',
+});
+
+for (let i = 0; i < SERVERS_COUNT; i++) {
+  cluster.fork({
+    PORT: 3000 + i
+  });
+}

examples/postgres-adapter-example/compose.yaml

@@ -0,0 +1,7 @@
+services:
+  postgres:
+    image: postgres:14
+    ports:
+      - "5432:5432"
+    environment:
+      POSTGRES_PASSWORD: "changeit"

examples/postgres-adapter-example/package.json

@@ -0,0 +1,12 @@
+{
+  "private": true,
+  "name": "postgres-adapter-example",
+  "version": "0.0.1",
+  "type": "module",
+  "dependencies": {
+    "@socket.io/postgres-adapter": "^0.4.0",
+    "pg": "^8.12.0",
+    "socket.io": "^4.7.5",
+    "socket.io-client": "^4.7.5"
+  }
+}

examples/postgres-adapter-example/server.js

@@ -0,0 +1,40 @@
+import { Server } from "socket.io";
+import { createAdapter } from "@socket.io/postgres-adapter";
+import pg from "pg";
+import process from "node:process";
+
+const PORT = process.env.PORT || 3000;
+
+const pool = new pg.Pool({
+  user: "postgres",
+  host: "localhost",
+  database: "postgres",
+  password: "changeit",
+  port: 5432,
+});
+
+await pool.query(`
+  CREATE TABLE IF NOT EXISTS socket_io_attachments (
+      id          bigserial UNIQUE,
+      created_at  timestamptz DEFAULT NOW(),
+      payload     bytea
+  );
+`);
+
+pool.on("error", (err) => {
+  console.error("Postgres error", err);
+});
+
+const io = new Server({
+  adapter: createAdapter(pool)
+});
+
+io.on("connection", (socket) => {
+  socket.on("hello", () => {
+    // send to anyone except the sender
+    socket.broadcast.emit("hello", socket.id, process.pid);
+  });
+});
+
+io.listen(PORT);
+console.log(`server listening on port ${PORT}`);

package-lock.json

@@ -4,6 +4,7 @@
   "requires": true,
   "packages": {
     "": {
+      "name": "socket.io",
       "workspaces": [
         "packages/socket.io-component-emitter",
         "packages/engine.io-parser",
@@ -51,7 +52,7 @@
         "mocha": "^10.6.0",
         "node-forge": "^1.3.1",
         "nyc": "^17.0.0",
-        "prettier": "^2.8.8",
+        "prettier": "^3.3.2",
         "redis": "^4.6.15",
         "rimraf": "^6.0.0",
         "rollup": "^2.79.1",
@@ -66,7 +67,7 @@
         "ts-node": "^10.9.2",
         "tsd": "^0.31.1",
         "typescript": "^5.5.3",
-        "uWebSockets.js": "github:uNetworking/uWebSockets.js#v20.30.0",
+        "uWebSockets.js": "github:uNetworking/uWebSockets.js#v20.48.0",
         "wdio-geckodriver-service": "^5.0.2"
       }
     },
@@ -11320,15 +11321,15 @@
       }
     },
     "node_modules/prettier": {
-      "version": "2.8.8",
-      "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.8.8.tgz",
-      "integrity": "sha512-tdN8qQGvNjw4CHbY+XXk0JgCXn9QiF21a55rBe5LJAU+kDyC4WQn4+awm2Xfk2lQMk5fKup9XgzTZtGkjBdP9Q==",
+      "version": "3.3.3",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-3.3.3.tgz",
+      "integrity": "sha512-i2tDNA0O5IrMO757lfrdQZCc2jPNDVntV0m/+4whiDfWaTKfMNgR7Qz0NAeGz/nRqF4m5/6CLzbP4/liHt12Ew==",
       "dev": true,
       "bin": {
-        "prettier": "bin-prettier.js"
+        "prettier": "bin/prettier.cjs"
       },
       "engines": {
-        "node": ">=10.13.0"
+        "node": ">=14"
       },
       "funding": {
         "url": "https://github.com/prettier/prettier?sponsor=1"
@@ -14206,9 +14207,10 @@
       }
     },
     "node_modules/uWebSockets.js": {
-      "version": "20.30.0",
-      "resolved": "git+ssh://git@github.com/uNetworking/uWebSockets.js.git#d39d4181daf5b670d44cbc1b18f8c28c85fd4142",
-      "dev": true
+      "version": "20.48.0",
+      "resolved": "git+ssh://git@github.com/uNetworking/uWebSockets.js.git#51ae1d1fd92dff77cbbdc7c431021f85578da1a6",
+      "dev": true,
+      "license": "Apache-2.0"
     },
     "node_modules/v8-compile-cache-lib": {
       "version": "3.0.1",
@@ -14945,14 +14947,6 @@
         }
       }
     },
-    "node_modules/xmlhttprequest-ssl": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/xmlhttprequest-ssl/-/xmlhttprequest-ssl-2.0.0.tgz",
-      "integrity": "sha512-QKxVRxiRACQcVuQEYFsI1hhkrMlrXHPegbbd1yn9UHOmRxY+si12nQYzri3vbzt8VdTTRviqcKxcyllFas5z2A==",
-      "engines": {
-        "node": ">=0.4.0"
-      }
-    },
     "node_modules/xtend": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
@@ -15194,34 +15188,24 @@
         "debug": "~4.3.1",
         "engine.io-parser": "~5.2.1",
         "ws": "~8.17.1",
-        "xmlhttprequest-ssl": "~2.0.0"
+        "xmlhttprequest-ssl": "~2.1.1"
+      }
+    },
+    "packages/engine.io-client/node_modules/xmlhttprequest-ssl": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/xmlhttprequest-ssl/-/xmlhttprequest-ssl-2.1.1.tgz",
+      "integrity": "sha512-ptjR8YSJIXoA3Mbv5po7RtSYHO6mZr8s7i5VGmEk7QY2pQWyT1o0N+W1gKbOyJPUCGXGnuw0wqe8f0L6Y0ny7g==",
+      "engines": {
+        "node": ">=0.4.0"
       }
     },
     "packages/engine.io-parser": {
       "version": "5.2.3",
       "license": "MIT",
-      "devDependencies": {
-        "prettier": "^3.3.2"
-      },
       "engines": {
         "node": ">=10.0.0"
       }
     },
-    "packages/engine.io-parser/node_modules/prettier": {
-      "version": "3.3.2",
-      "resolved": "https://registry.npmjs.org/prettier/-/prettier-3.3.2.tgz",
-      "integrity": "sha512-rAVeHYMcv8ATV5d508CFdn+8/pHPpXeIid1DdrPwXnaAdH7cqjVbpJaT5eq4yRAFU/lsbwYwSF/n5iNrdJHPQA==",
-      "dev": true,
-      "bin": {
-        "prettier": "bin/prettier.cjs"
-      },
-      "engines": {
-        "node": ">=14"
-      },
-      "funding": {
-        "url": "https://github.com/prettier/prettier?sponsor=1"
-      }
-    },
     "packages/engine.io/node_modules/debug": {
       "version": "4.3.3",
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.3.tgz",
@@ -15246,7 +15230,7 @@
         "base64id": "~2.0.0",
         "cors": "~2.8.5",
         "debug": "~4.3.2",
-        "engine.io": "~6.5.2",
+        "engine.io": "~6.6.0",
         "socket.io-adapter": "~2.5.2",
         "socket.io-parser": "~4.2.4"
       },
@@ -15268,7 +15252,7 @@
       "dependencies": {
         "@socket.io/component-emitter": "~3.1.0",
         "debug": "~4.3.2",
-        "engine.io-client": "~6.5.2",
+        "engine.io-client": "~6.6.0",
         "socket.io-parser": "~4.2.4"
       },
       "engines": {
@@ -15291,19 +15275,8 @@
         }
       }
     },
-    "packages/socket.io-client/node_modules/engine.io-client": {
-      "version": "6.5.4",
-      "resolved": "https://registry.npmjs.org/engine.io-client/-/engine.io-client-6.5.4.tgz",
-      "integrity": "sha512-GeZeeRjpD2qf49cZQ0Wvh/8NJNfeXkXXcoGh+F77oEAgo9gUHwT1fCRxSNU+YEEaysOJTnsFHmM5oAcPy4ntvQ==",
-      "dependencies": {
-        "@socket.io/component-emitter": "~3.1.0",
-        "debug": "~4.3.1",
-        "engine.io-parser": "~5.2.1",
-        "ws": "~8.17.1",
-        "xmlhttprequest-ssl": "~2.0.0"
-      }
-    },
     "packages/socket.io-cluster-engine": {
+      "name": "@socket.io/cluster-engine",
       "version": "0.1.0",
       "license": "MIT",
       "dependencies": {
@@ -15359,26 +15332,6 @@
           "optional": true
         }
       }
-    },
-    "packages/socket.io/node_modules/engine.io": {
-      "version": "6.5.5",
-      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-6.5.5.tgz",
-      "integrity": "sha512-C5Pn8Wk+1vKBoHghJODM63yk8MvrO9EWZUfkAt5HAqIgPE4/8FF0PEGHXtEd40l223+cE5ABWuPzm38PHFXfMA==",
-      "dependencies": {
-        "@types/cookie": "^0.4.1",
-        "@types/cors": "^2.8.12",
-        "@types/node": ">=10.0.0",
-        "accepts": "~1.3.4",
-        "base64id": "2.0.0",
-        "cookie": "~0.4.1",
-        "cors": "~2.8.5",
-        "debug": "~4.3.1",
-        "engine.io-parser": "~5.2.1",
-        "ws": "~8.17.1"
-      },
-      "engines": {
-        "node": ">=10.2.0"
-      }
     }
   }
 }

package.json

@@ -1,4 +1,5 @@
 {
+  "name": "socket.io",
   "private": true,
   "workspaces": [
     "packages/socket.io-component-emitter",
@@ -52,7 +53,7 @@
     "mocha": "^10.6.0",
     "node-forge": "^1.3.1",
     "nyc": "^17.0.0",
-    "prettier": "^2.8.8",
+    "prettier": "^3.3.2",
     "redis": "^4.6.15",
     "rimraf": "^6.0.0",
     "rollup": "^2.79.1",
@@ -67,7 +68,7 @@
     "ts-node": "^10.9.2",
     "tsd": "^0.31.1",
     "typescript": "^5.5.3",
-    "uWebSockets.js": "github:uNetworking/uWebSockets.js#v20.30.0",
+    "uWebSockets.js": "github:uNetworking/uWebSockets.js#v20.48.0",
     "wdio-geckodriver-service": "^5.0.2"
   }
 }

packages/engine.io-client/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 | Version                                                                                                     | Release date   | Bundle size (UMD min+gzip) |
 |-------------------------------------------------------------------------------------------------------------|----------------|----------------------------|
+| [6.6.1](#661-2024-09-21)                                                                                    | September 2024 | `8.7 KB`                   |
 | [6.6.0](#660-2024-06-21)                                                                                    | June 2024      | `8.6 KB`                   |
 | [6.5.4](#654-2024-06-18) (from the [6.5.x](https://github.com/socketio/engine.io-client/tree/6.5.x) branch) | June 2024      | `8.8 KB`                   |
 | [3.5.4](#354-2024-06-18) (from the [3.5.x](https://github.com/socketio/engine.io-client/tree/3.5.x) branch) | June 2024      | `-`                        |
@@ -38,6 +39,27 @@
 
 # Release notes
 
+## [6.6.1](https://github.com/socketio/socket.io/compare/engine.io-client@6.6.0...engine.io-client@6.6.1) (2024-09-21)
+
+
+### Bug Fixes
+
+* move 'offline' event listener at the top ([8a2f5a3](https://github.com/socketio/socket.io/commit/8a2f5a3da0addb386e7a0f4970e1a9696b82797e))
+* only remove the event listener if it exists ([9b3c9ab](https://github.com/socketio/socket.io/commit/9b3c9abecab028822357beb6e2b502f548e312eb)), closes [/github.com/socketio/socket.io/issues/5088#issuecomment-2217202350](https://github.com//github.com/socketio/socket.io/issues/5088/issues/issuecomment-2217202350)
+* do not send a packet on an expired connection ([#5134](https://github.com/socketio/socket.io/issues/5134)) ([8adcfbf](https://github.com/socketio/socket.io/commit/8adcfbfde50679095ec2abe376650cf2b6814325))
+
+
+### Performance Improvements
+
+* do not reset the heartbeat timer on each packet ([7a23dde](https://github.com/socketio/socket.io/commit/7a23dde6efff3079edeeda951fe0ee25516da833))
+
+
+### Dependencies
+
+- [`ws@~8.17.1`](https://github.com/websockets/ws/releases/tag/8.17.1) (no change)
+
+
+
 ## [6.6.0](https://github.com/socketio/engine.io-client/compare/6.5.3...6.6.0) (2024-06-21)
 
 

packages/engine.io-client/lib/globals.node.ts

@@ -55,7 +55,7 @@ export function parse(setCookieString: string): Cookie {
       case "Max-Age":
         const expiration = new Date();
         expiration.setUTCSeconds(
-          expiration.getUTCSeconds() + parseInt(value, 10)
+          expiration.getUTCSeconds() + parseInt(value, 10),
         );
         cookie.expires = expiration;
         break;

packages/engine.io-client/lib/socket.ts

@@ -10,11 +10,34 @@ import {
   CookieJar,
   createCookieJar,
   defaultBinaryType,
+  nextTick,
 } from "./globals.node.js";
 import debugModule from "debug"; // debug()
 
 const debug = debugModule("engine.io-client:socket"); // debug()
 
+const withEventListeners =
+  typeof addEventListener === "function" &&
+  typeof removeEventListener === "function";
+
+const OFFLINE_EVENT_LISTENERS = [];
+
+if (withEventListeners) {
+  // within a ServiceWorker, any event handler for the 'offline' event must be added on the initial evaluation of the
+  // script, so we create one single event listener here which will forward the event to the socket instances
+  addEventListener(
+    "offline",
+    () => {
+      debug(
+        "closing %d connection(s) because the network was lost",
+        OFFLINE_EVENT_LISTENERS.length,
+      );
+      OFFLINE_EVENT_LISTENERS.forEach((listener) => listener());
+    },
+    false,
+  );
+}
+
 export interface SocketOptions {
   /**
    * The host that we're connecting to. Set from the URI passed when connecting
@@ -85,7 +108,9 @@ export interface SocketOptions {
    *
    * @default ['polling','websocket', 'webtransport']
    */
-  transports?: string[] | TransportCtor[];
+  transports?:
+    | ("polling" | "websocket" | "webtransport" | string)[]
+    | TransportCtor[];
 
   /**
    * Whether all the transports should be tested, instead of just the first one.
@@ -318,6 +343,11 @@ export class SocketWithoutUpgrade extends Emitter<
   private _pingTimeout: number = -1;
   private _maxPayload?: number = -1;
   private _pingTimeoutTimer: NodeJS.Timer;
+  /**
+   * The expiration timestamp of the {@link _pingTimeoutTimer} object is tracked, in case the timer is throttled and the
+   * callback is not fired on time. This can happen for example when a laptop is suspended or when a phone is locked.
+   */
+  private _pingTimeoutTime = Infinity;
   private clearTimeoutFn: typeof clearTimeout;
   private readonly _beforeunloadEventListener: () => void;
   private readonly _offlineEventListener: () => void;
@@ -379,8 +409,8 @@ export class SocketWithoutUpgrade extends Emitter<
       (typeof location !== "undefined" && location.port
         ? location.port
         : this.secure
-        ? "443"
-        : "80");
+          ? "443"
+          : "80");
 
     this.transports = [];
     this._transportsByName = {};
@@ -406,7 +436,7 @@ export class SocketWithoutUpgrade extends Emitter<
         transportOptions: {},
         closeOnBeforeunload: false,
       },
-      opts
+      opts,
     );
 
     this.opts.path =
@@ -417,7 +447,7 @@ export class SocketWithoutUpgrade extends Emitter<
       this.opts.query = decode(this.opts.query);
     }
 
-    if (typeof addEventListener === "function") {
+    if (withEventListeners) {
       if (this.opts.closeOnBeforeunload) {
         // Firefox closes the connection when the "beforeunload" event is emitted but not Chrome. This event listener
         // ensures every browser behaves the same (no "disconnect" event at the Socket.IO level when the page is
@@ -432,16 +462,17 @@ export class SocketWithoutUpgrade extends Emitter<
         addEventListener(
           "beforeunload",
           this._beforeunloadEventListener,
-          false
+          false,
         );
       }
       if (this.hostname !== "localhost") {
+        debug("adding listener for the 'offline' event");
         this._offlineEventListener = () => {
           this._onClose("transport close", {
             description: "network connection lost",
           });
         };
-        addEventListener("offline", this._offlineEventListener, false);
+        OFFLINE_EVENT_LISTENERS.push(this._offlineEventListener);
       }
     }
 
@@ -482,7 +513,7 @@ export class SocketWithoutUpgrade extends Emitter<
         secure: this.secure,
         port: this.port,
       },
-      this.opts.transportOptions[name]
+      this.opts.transportOptions[name],
     );
 
     debug("options: %j", opts);
@@ -572,7 +603,6 @@ export class SocketWithoutUpgrade extends Emitter<
 
       // Socket is live - any packet counts
       this.emitReserved("heartbeat");
-      this._resetPingTimeout();
 
       switch (packet.type) {
         case "open":
@@ -583,6 +613,7 @@ export class SocketWithoutUpgrade extends Emitter<
           this._sendPacket("pong");
           this.emitReserved("ping");
           this.emitReserved("pong");
+          this._resetPingTimeout();
           break;
 
         case "error":
@@ -628,9 +659,11 @@ export class SocketWithoutUpgrade extends Emitter<
    */
   private _resetPingTimeout() {
     this.clearTimeoutFn(this._pingTimeoutTimer);
+    const delay = this._pingInterval + this._pingTimeout;
+    this._pingTimeoutTime = Date.now() + delay;
     this._pingTimeoutTimer = this.setTimeoutFn(() => {
       this._onClose("ping timeout");
-    }, this._pingInterval + this._pingTimeout);
+    }, delay);
     if (this.opts.autoUnref) {
       this._pingTimeoutTimer.unref();
     }
@@ -708,6 +741,31 @@ export class SocketWithoutUpgrade extends Emitter<
     return this.writeBuffer;
   }
 
+  /**
+   * Checks whether the heartbeat timer has expired but the socket has not yet been notified.
+   *
+   * Note: this method is private for now because it does not really fit the WebSocket API, but if we put it in the
+   * `write()` method then the message would not be buffered by the Socket.IO client.
+   *
+   * @return {boolean}
+   * @private
+   */
+  /* private */ _hasPingExpired() {
+    if (!this._pingTimeoutTime) return true;
+
+    const hasExpired = Date.now() > this._pingTimeoutTime;
+    if (hasExpired) {
+      debug("throttled timer detected, scheduling connection close");
+      this._pingTimeoutTime = 0;
+
+      nextTick(() => {
+        this._onClose("ping timeout");
+      }, this.setTimeoutFn);
+    }
+
+    return hasExpired;
+  }
+
   /**
    * Sends a message.
    *
@@ -747,7 +805,7 @@ export class SocketWithoutUpgrade extends Emitter<
     type: PacketType,
     data?: RawData,
     options?: WriteOptions,
-    fn?: () => void
+    fn?: () => void,
   ) {
     if ("function" === typeof data) {
       fn = data;
@@ -868,13 +926,21 @@ export class SocketWithoutUpgrade extends Emitter<
       // ignore further transport communication
       this.transport.removeAllListeners();
 
-      if (typeof removeEventListener === "function") {
-        removeEventListener(
-          "beforeunload",
-          this._beforeunloadEventListener,
-          false
-        );
-        removeEventListener("offline", this._offlineEventListener, false);
+      if (withEventListeners) {
+        if (this._beforeunloadEventListener) {
+          removeEventListener(
+            "beforeunload",
+            this._beforeunloadEventListener,
+            false,
+          );
+        }
+        if (this._offlineEventListener) {
+          const i = OFFLINE_EVENT_LISTENERS.indexOf(this._offlineEventListener);
+          if (i !== -1) {
+            debug("removing listener for the 'offline' event");
+            OFFLINE_EVENT_LISTENERS.splice(i, 1);
+          }
+        }
       }
 
       // set ready state

packages/engine.io-client/lib/transport.ts

@@ -14,7 +14,7 @@ export class TransportError extends Error {
   constructor(
     reason: string,
     readonly description: any,
-    readonly context: any
+    readonly context: any,
   ) {
     super(reason);
   }
@@ -79,7 +79,7 @@ export abstract class Transport extends Emitter<
   protected onError(reason: string, description: any, context?: any) {
     super.emitReserved(
       "error",
-      new TransportError(reason, description, context)
+      new TransportError(reason, description, context),
     );
     return this;
   }

packages/engine.io-client/lib/transports/polling-xhr.node.ts

@@ -15,12 +15,12 @@ export class XHR extends BaseXHR {
     Object.assign(
       opts,
       { xd: this.xd, cookieJar: this.socket?._cookieJar },
-      this.opts
+      this.opts,
     );
     return new Request(
       (opts) => new XMLHttpRequest(opts),
       this.uri(),
-      opts as RequestOptions
+      opts as RequestOptions,
     );
   }
 }

packages/engine.io-client/lib/transports/polling-xhr.ts

@@ -122,7 +122,7 @@ export class Request extends Emitter<
   constructor(
     private readonly createRequest: (opts: RequestOptions) => XMLHttpRequest,
     uri: string,
-    opts: RequestOptions
+    opts: RequestOptions,
   ) {
     super();
     installTimerFunctions(this, opts);
@@ -151,7 +151,7 @@ export class Request extends Emitter<
       "ca",
       "ciphers",
       "rejectUnauthorized",
-      "autoUnref"
+      "autoUnref",
     );
     opts.xdomain = !!this._opts.xd;
 
@@ -197,7 +197,7 @@ export class Request extends Emitter<
         if (xhr.readyState === 3) {
           this._opts.cookieJar?.parseCookies(
             // @ts-ignore
-            xhr.getResponseHeader("set-cookie")
+            xhr.getResponseHeader("set-cookie"),
           );
         }
 
@@ -354,7 +354,7 @@ function newRequest(opts) {
   if (!xdomain) {
     try {
       return new globalThis[["Active"].concat("Object").join("X")](
-        "Microsoft.XMLHTTP"
+        "Microsoft.XMLHTTP",
       );
     } catch (e) {}
   }

packages/engine.io-client/lib/transports/websocket.node.ts

@@ -14,7 +14,7 @@ export class WS extends BaseWS {
   createSocket(
     uri: string,
     protocols: string | string[] | undefined,
-    opts: Record<string, any>
+    opts: Record<string, any>,
   ) {
     if (this.socket?._cookieJar) {
       opts.headers = opts.headers || {};

packages/engine.io-client/lib/transports/websocket.ts

@@ -43,7 +43,7 @@ export abstract class BaseWS extends Transport {
           "origin",
           "maxPayload",
           "family",
-          "checkServerIdentity"
+          "checkServerIdentity",
         );
 
     if (this.opts.extraHeaders) {
@@ -64,7 +64,7 @@ export abstract class BaseWS extends Transport {
   abstract createSocket(
     uri: string,
     protocols: string | string[] | undefined,
-    opts: Record<string, any>
+    opts: Record<string, any>,
   );
 
   /**
@@ -166,7 +166,7 @@ export class WS extends BaseWS {
   createSocket(
     uri: string,
     protocols: string | string[] | undefined,
-    opts: Record<string, any>
+    opts: Record<string, any>,
   ) {
     return !isReactNative
       ? protocols

packages/engine.io-client/lib/transports/webtransport.ts

@@ -30,7 +30,7 @@ export class WT extends Transport {
       // @ts-ignore
       this._transport = new WebTransport(
         this.createUri("https"),
-        this.opts.transportOptions[this.name]
+        this.opts.transportOptions[this.name],
       );
     } catch (err) {
       return this.emitReserved("error", err);
@@ -51,7 +51,7 @@ export class WT extends Transport {
       this._transport.createBidirectionalStream().then((stream) => {
         const decoderStream = createPacketDecoderStream(
           Number.MAX_SAFE_INTEGER,
-          this.socket.binaryType
+          this.socket.binaryType,
         );
         const reader = stream.readable.pipeThrough(decoderStream).getReader();
 

packages/engine.io-client/package.json

@@ -2,7 +2,7 @@
   "name": "engine.io-client",
   "description": "Client for the realtime Engine",
   "license": "MIT",
-  "version": "6.6.0",
+  "version": "6.6.1",
   "main": "./build/cjs/index.js",
   "module": "./build/esm/index.js",
   "exports": {
@@ -56,7 +56,7 @@
     "debug": "~4.3.1",
     "engine.io-parser": "~5.2.1",
     "ws": "~8.17.1",
-    "xmlhttprequest-ssl": "~2.0.0"
+    "xmlhttprequest-ssl": "~2.1.1"
   },
   "scripts": {
     "compile": "rimraf ./build && tsc && tsc -p tsconfig.esm.json && ./postcompile.sh",

packages/engine.io-client/test/connection.js

@@ -34,12 +34,12 @@ describe("connection", function () {
     const socket = new Socket();
     socket.on("open", () => {
       socket.send(
-        "\uD800\uDC00-\uDB7F\uDFFF\uDB80\uDC00-\uDBFF\uDFFF\uE000-\uF8FF"
+        "\uD800\uDC00-\uDB7F\uDFFF\uDB80\uDC00-\uDBFF\uDFFF\uE000-\uF8FF",
       );
       socket.on("message", (data) => {
         if ("hi" === data) return;
         expect(data).to.be(
-          "\uD800\uDC00-\uDB7F\uDFFF\uDB80\uDC00-\uDBFF\uDFFF\uE000-\uF8FF"
+          "\uD800\uDC00-\uDB7F\uDFFF\uDB80\uDC00-\uDBFF\uDFFF\uE000-\uF8FF",
         );
         socket.close();
         done();
@@ -59,7 +59,7 @@ describe("connection", function () {
       setTimeout(() => {
         expect(noPacket).to.be(true);
         done();
-      }, 1200);
+      }, 200);
     });
   });
 
@@ -177,7 +177,7 @@ describe("connection", function () {
         setTimeout(() => {
           expect(noPacket).to.be(true);
           done();
-        }, 1200);
+        }, 200);
       });
     });
 

packages/engine.io-client/test/fixtures/no-unref.js

@@ -5,4 +5,4 @@ const socket = new Socket("http://localhost:3000", {
 
 setTimeout(() => {
   console.log("process should not exit");
-}, 500);
+}, 50);

packages/engine.io-client/test/fixtures/unref-polling-only.js

@@ -10,4 +10,4 @@ socket.on("open", () => {
 
 setTimeout(() => {
   console.log("process should exit now");
-}, 500);
+}, 50);

packages/engine.io-client/test/fixtures/unref-websocket-only.js

@@ -10,4 +10,4 @@ socket.on("open", () => {
 
 setTimeout(() => {
   console.log("process should exit now");
-}, 500);
+}, 50);

packages/engine.io-client/test/fixtures/unref.js

@@ -9,4 +9,4 @@ socket.on("open", () => {
 
 setTimeout(() => {
   console.log("process should exit now");
-}, 500);
+}, 50);

packages/engine.io-client/test/node.js

@@ -34,7 +34,7 @@ describe("node.js", () => {
         isComplete = true;
         process.kill();
         done();
-      }, 1000);
+      }, 100);
     });
   });
 

packages/engine.io-client/test/socket.js

@@ -90,7 +90,7 @@ describe("Socket", function () {
 
     socket.on("error", (err) => {
       expect(err.message).to.eql(
-        useFetch ? "fetch read error" : "xhr poll error"
+        useFetch ? "fetch read error" : "xhr poll error",
       );
       done();
     });
@@ -237,7 +237,7 @@ describe("Socket", function () {
           // err.context is a XMLHttpRequest object
           expect(err.context.readyState).to.eql(4);
           expect(err.context.responseText).to.eql(
-            '{"code":1,"message":"Session ID unknown"}'
+            '{"code":1,"message":"Session ID unknown"}',
           );
         }
       });
@@ -270,4 +270,30 @@ describe("Socket", function () {
       });
     });
   });
+
+  describe("throttled timer", () => {
+    it("checks the state of the timer", (done) => {
+      const socket = new Socket();
+
+      expect(socket._hasPingExpired()).to.be(false);
+
+      socket.on("open", () => {
+        expect(socket._hasPingExpired()).to.be(false);
+
+        // simulate a throttled timer
+        socket._pingTimeoutTime = Date.now() - 1;
+
+        expect(socket._hasPingExpired()).to.be(true);
+
+        // subsequent calls should not trigger more 'close' events
+        expect(socket._hasPingExpired()).to.be(true);
+        expect(socket._hasPingExpired()).to.be(true);
+      });
+
+      socket.on("close", (reason) => {
+        expect(reason).to.eql("ping timeout");
+        done();
+      });
+    });
+  });
 });

packages/engine.io-client/test/support/hooks.js

@@ -21,7 +21,7 @@ exports.mochaHooks = {
       maxHttpBufferSize: 100,
       allowRequest: (req, fn) => {
         const denyRequest = new URL(`http://${req.url}`).searchParams.has(
-          "deny"
+          "deny",
         );
         fn(null, !denyRequest);
       },

packages/engine.io-client/test/transport.js

@@ -100,7 +100,7 @@ describe("Transport", () => {
         timestampRequests: false,
       });
       expect(polling.uri()).to.contain(
-        "http://localhost:3000/engine.io?sid=test"
+        "http://localhost:3000/engine.io?sid=test",
       );
     });
 
@@ -124,7 +124,7 @@ describe("Transport", () => {
         timestampRequests: true,
       });
       expect(polling.uri()).to.match(
-        /http:\/\/localhost\/engine\.io\?(j=[0-9]+&)?(t=[0-9A-Za-z-_]+)/
+        /http:\/\/localhost\/engine\.io\?(j=[0-9]+&)?(t=[0-9A-Za-z-_]+)/,
       );
     });
 
@@ -180,7 +180,7 @@ describe("Transport", () => {
         timestampRequests: true,
       });
       expect(ws.uri()).to.match(
-        /ws:\/\/localhost\/engine\.io\?woot=[0-9A-Za-z-_]+/
+        /ws:\/\/localhost\/engine\.io\?woot=[0-9A-Za-z-_]+/,
       );
     });
 

packages/engine.io-client/test/webtransport.mjs

@@ -17,7 +17,7 @@ async function setup(opts, cb) {
     [{ shortName: "CN", value: "localhost" }],
     {
       days: 14, // the total length of the validity period MUST NOT exceed two weeks (https://w3c.github.io/webtransport/#custom-certificate-requirements)
-    }
+    },
   );
 
   const engine = new Server(opts);
@@ -73,8 +73,8 @@ function createSocket(port, certificate, opts) {
           },
         },
       },
-      opts
-    )
+      opts,
+    ),
   );
 }
 
@@ -113,7 +113,7 @@ describe("WebTransport", () => {
           httpServer.close();
           success(engine, h3Server, done);
         });
-      }
+      },
     );
   });
 
@@ -137,7 +137,7 @@ describe("WebTransport", () => {
           httpServer.close();
           success(engine, h3Server, done);
         });
-      }
+      },
     );
   });
 
@@ -160,7 +160,7 @@ describe("WebTransport", () => {
             success(engine, h3Server, done);
           }
         });
-      }
+      },
     );
   });
 

packages/engine.io-client/zuul.config.js

@@ -1,56 +0,0 @@
-'use strict';
-
-const browsers = require('socket.io-browsers');
-
-const zuulConfig = module.exports = {
-  ui: 'mocha-bdd',
-
-  // test on localhost by default
-  local: true,
-  open: true,
-
-  concurrency: 2, // ngrok only accepts two tunnels by default
-  // if browser does not sends output in 120s since last output:
-  // stop testing, something is wrong
-  browser_output_timeout: 120 * 1000,
-  browser_open_timeout: 60 * 4 * 1000,
-  // we want to be notified something is wrong asap, so no retry
-  browser_retries: 1,
-
-  server: './test/support/server.js',
-  builder: 'zuul-builder-webpack',
-  webpack: require('./support/webpack.config.js')
-};
-
-if (process.env.CI === 'true') {
-  zuulConfig.local = false;
-  zuulConfig.tunnel = {
-    type: 'ngrok',
-    bind_tls: true
-  };
-}
-
-zuulConfig.browsers = [
-  {
-    name: 'firefox',
-    version: 'latest'
-  }, {
-    name: 'internet explorer',
-    version: '9..11'
-  }, {
-    name: 'safari',
-    version: '14'
-  }, {
-    name: 'iphone',
-    version: '14'
-  }, {
-    name: 'android',
-    version: '5.1..6.0'
-  }, {
-    name: 'ipad',
-    version: '14'
-  }, {
-    name: 'MicrosoftEdge',
-    version: 'latest'
-  }
-];

packages/engine.io-parser/package.json

@@ -10,9 +10,6 @@
     "require": "./build/cjs/index.js"
   },
   "types": "build/esm/index.d.ts",
-  "devDependencies": {
-    "prettier": "^3.3.2"
-  },
   "scripts": {
     "compile": "rimraf ./build && tsc && tsc -p tsconfig.esm.json && ./postcompile.sh",
     "test": "npm run format:check && npm run compile && if test \"$BROWSERS\" = \"1\" ; then npm run test:browser; else npm run test:node; fi",

packages/engine.io/lib/server.ts

@@ -78,7 +78,7 @@ export interface ServerOptions {
    */
   allowRequest?: (
     req: IncomingMessage,
-    fn: (err: string | null | undefined, success: boolean) => void
+    fn: (err: string | null | undefined, success: boolean) => void,
   ) => void;
   /**
    * The low-level transports that are enabled. WebTransport is disabled by default and must be manually enabled:
@@ -146,7 +146,7 @@ export interface ServerOptions {
 type Middleware = (
   req: IncomingMessage,
   res: ServerResponse,
-  next: (err?: any) => void
+  next: (err?: any) => void,
 ) => void;
 
 function parseSessionId(data: string) {
@@ -192,7 +192,7 @@ export abstract class BaseServer extends EventEmitter {
         cors: false,
         allowEIO3: false,
       },
-      opts
+      opts,
     );
 
     if (opts.cookie) {
@@ -204,7 +204,7 @@ export abstract class BaseServer extends EventEmitter {
           httpOnly: opts.cookie.path !== false,
           sameSite: "lax",
         },
-        opts.cookie
+        opts.cookie,
       );
     }
 
@@ -217,7 +217,7 @@ export abstract class BaseServer extends EventEmitter {
         {
           threshold: 1024,
         },
-        opts.perMessageDeflate
+        opts.perMessageDeflate,
       );
     }
 
@@ -263,7 +263,7 @@ export abstract class BaseServer extends EventEmitter {
   protected verify(
     req: any,
     upgrade: boolean,
-    fn: (errorCode?: number, errorContext?: any) => void
+    fn: (errorCode?: number, errorContext?: any) => void,
   ) {
     // transport check
     const transport = req._query.transport;
@@ -361,7 +361,7 @@ export abstract class BaseServer extends EventEmitter {
   protected _applyMiddlewares(
     req: IncomingMessage,
     res: ServerResponse,
-    callback: (err?: any) => void
+    callback: (err?: any) => void,
   ) {
     if (this.middlewares.length === 0) {
       debug("no middleware to apply, skipping");
@@ -424,7 +424,7 @@ export abstract class BaseServer extends EventEmitter {
   protected async handshake(
     transportName: string,
     req: any,
-    closeConnection: (errorCode?: number, errorContext?: any) => void
+    closeConnection: (errorCode?: number, errorContext?: any) => void,
   ) {
     const protocol = req._query.EIO === "4" ? 4 : 3; // 3rd revision by default
     if (protocol === 3 && !this.opts.allowEIO3) {
@@ -519,7 +519,7 @@ export abstract class BaseServer extends EventEmitter {
   public async onWebTransportSession(session: any) {
     const timeout = setTimeout(() => {
       debug(
-        "the client failed to establish a bidirectional stream in the given period"
+        "the client failed to establish a bidirectional stream in the given period",
       );
       session.close();
     }, this.opts.upgradeTimeout);
@@ -535,7 +535,7 @@ export abstract class BaseServer extends EventEmitter {
     const stream = result.value;
     const transformStream = createPacketDecoderStream(
       this.opts.maxHttpBufferSize,
-      "nodebuffer"
+      "nodebuffer",
     );
     const reader = stream.readable.pipeThrough(transformStream).getReader();
 
@@ -632,7 +632,10 @@ export abstract class BaseServer extends EventEmitter {
  * @see https://nodejs.org/api/http.html#class-httpserverresponse
  */
 class WebSocketResponse {
-  constructor(readonly req, readonly socket: Duplex) {
+  constructor(
+    readonly req,
+    readonly socket: Duplex,
+  ) {
     // temporarily store the response headers on the req object (see the "headers" event)
     req[kResponseHeaders] = {};
   }
@@ -659,6 +662,9 @@ class WebSocketResponse {
   }
 }
 
+/**
+ * An Engine.IO server based on Node.js built-in HTTP server and the `ws` package for WebSocket connections.
+ */
 export class Server extends BaseServer {
   public httpServer?: HttpServer;
   private ws: any;
@@ -776,7 +782,7 @@ export class Server extends BaseServer {
   public handleUpgrade(
     req: EngineRequest,
     socket: Duplex,
-    upgradeHead: Buffer
+    upgradeHead: Buffer,
   ) {
     this.prepare(req);
 
@@ -953,7 +959,7 @@ function abortRequest(res, errorCode, errorContext) {
     JSON.stringify({
       code: errorCode,
       message,
-    })
+    }),
   );
 }
 
@@ -968,7 +974,7 @@ function abortRequest(res, errorCode, errorContext) {
 function abortUpgrade(
   socket,
   errorCode,
-  errorContext: { message?: string } = {}
+  errorContext: { message?: string } = {},
 ) {
   socket.on("error", () => {
     debug("ignoring error from closed connection");
@@ -984,7 +990,7 @@ function abortUpgrade(
         length +
         "\r\n" +
         "\r\n" +
-        message
+        message,
     );
   }
   socket.destroy();

packages/engine.io/lib/socket.ts

@@ -80,7 +80,7 @@ export class Socket extends EventEmitter {
     server: BaseServer,
     transport: Transport,
     req: EngineRequest,
-    protocol: number
+    protocol: number,
   ) {
     super();
     this.id = id;
@@ -125,7 +125,7 @@ export class Socket extends EventEmitter {
         pingInterval: this.server.opts.pingInterval,
         pingTimeout: this.server.opts.pingTimeout,
         maxPayload: this.server.opts.maxHttpBufferSize,
-      })
+      }),
     );
 
     if (this.server.opts.initialPacket) {
@@ -212,7 +212,7 @@ export class Socket extends EventEmitter {
     this.pingIntervalTimer = setTimeout(() => {
       debug(
         "writing ping packet - expecting pong within %sms",
-        this.server.opts.pingTimeout
+        this.server.opts.pingTimeout,
       );
       this.sendPacket("ping");
       this.resetPingTimeout();
@@ -233,7 +233,7 @@ export class Socket extends EventEmitter {
       },
       this.protocol === 3
         ? this.server.opts.pingInterval + this.server.opts.pingTimeout
-        : this.server.opts.pingTimeout
+        : this.server.opts.pingTimeout,
     );
   }
 
@@ -293,7 +293,7 @@ export class Socket extends EventEmitter {
     debug(
       'might upgrade socket transport from "%s" to "%s"',
       this.transport.name,
-      transport.name
+      transport.name,
     );
 
     this.upgrading = true;
@@ -468,7 +468,7 @@ export class Socket extends EventEmitter {
     type: PacketType,
     data?: RawData,
     options: SendOptions = {},
-    callback?: SendCallback
+    callback?: SendCallback,
   ) {
     if ("function" === typeof options) {
       callback = options;
@@ -554,6 +554,13 @@ export class Socket extends EventEmitter {
    * @return {Socket} for chaining
    */
   public close(discard?: boolean) {
+    if (
+      discard &&
+      (this.readyState === "open" || this.readyState === "closing")
+    ) {
+      return this.closeTransport(discard);
+    }
+
     if ("open" !== this.readyState) return;
 
     this.readyState = "closing";
@@ -561,7 +568,7 @@ export class Socket extends EventEmitter {
     if (this.writeBuffer.length) {
       debug(
         "there are %d remaining packets in the buffer, waiting for the 'drain' event",
-        this.writeBuffer.length
+        this.writeBuffer.length,
       );
       this.once("drain", () => {
         debug("all packets have been sent, closing the transport");
@@ -570,7 +577,7 @@ export class Socket extends EventEmitter {
       return;
     }
 
-    debug("the buffer is empty, closing the transport right away", discard);
+    debug("the buffer is empty, closing the transport right away");
     this.closeTransport(discard);
   }
 
@@ -581,7 +588,7 @@ export class Socket extends EventEmitter {
    * @private
    */
   private closeTransport(discard: boolean) {
-    debug("closing the transport (discard? %s)", discard);
+    debug("closing the transport (discard? %s)", !!discard);
     if (discard) this.transport.discard();
     this.transport.close(this.onClose.bind(this, "forced close"));
   }

packages/engine.io/lib/transport.ts

@@ -69,7 +69,7 @@ export abstract class Transport extends EventEmitter {
       "readyState updated from %s to %s (%s)",
       this._readyState,
       state,
-      this.name
+      this.name,
     );
     this._readyState = state;
   }

packages/engine.io/lib/transports/websocket.ts

@@ -54,13 +54,13 @@ export class WebSocket extends Transport {
         this.socket._sender.sendFrame(
           // @ts-ignore
           packet.options.wsPreEncodedFrame,
-          isLast ? this._onSentLast : this._onSent
+          isLast ? this._onSentLast : this._onSent,
         );
       } else {
         this.parser.encodePacket(
           packet,
           this.supportsBinary,
-          isLast ? this._doSendLast : this._doSend
+          isLast ? this._doSendLast : this._doSend,
         );
       }
     }

packages/engine.io/lib/transports/webtransport.ts

@@ -10,7 +10,11 @@ const debug = debugModule("engine:webtransport");
 export class WebTransport extends Transport {
   private readonly writer;
 
-  constructor(private readonly session, stream, reader) {
+  constructor(
+    private readonly session,
+    stream,
+    reader,
+  ) {
     super({ _query: { EIO: "4" } });
 
     const transformStream = createPacketEncoderStream();

packages/engine.io/lib/userver.ts

@@ -23,6 +23,10 @@ export interface uOptions {
   maxBackpressure?: number;
 }
 
+/**
+ * An Engine.IO server based on the `uWebSockets.js` package.
+ */
+// TODO export it into its own package
 export class uServer extends BaseServer {
   protected init() {}
   protected cleanup() {}
@@ -64,7 +68,7 @@ export class uServer extends BaseServer {
    */
   public attach(
     app /* : TemplatedApp */,
-    options: AttachOptions & uOptions = {}
+    options: AttachOptions & uOptions = {},
   ) {
     const path = this._computePath(options);
     (app as TemplatedApp)
@@ -84,7 +88,7 @@ export class uServer extends BaseServer {
         },
         message: (ws, message, isBinary) => {
           ws.getUserData().transport.onData(
-            isBinary ? message : Buffer.from(message).toString()
+            isBinary ? message : Buffer.from(message).toString(),
           );
         },
         close: (ws, code, message) => {
@@ -96,7 +100,7 @@ export class uServer extends BaseServer {
   override _applyMiddlewares(
     req: any,
     res: any,
-    callback: (err?: any) => void
+    callback: (err?: any) => void,
   ): void {
     if (this.middlewares.length === 0) {
       return callback();
@@ -116,7 +120,7 @@ export class uServer extends BaseServer {
 
   private handleRequest(
     res: HttpResponse,
-    req: HttpRequest & { res: any; _query: any }
+    req: HttpRequest & { res: any; _query: any },
   ) {
     debug('handling "%s" http request "%s"', req.getMethod(), req.getUrl());
     this.prepare(req, res);
@@ -158,7 +162,7 @@ export class uServer extends BaseServer {
   private handleUpgrade(
     res: HttpResponse,
     req: HttpRequest & { res: any; _query: any },
-    context
+    context,
   ) {
     debug("on upgrade");
 
@@ -185,13 +189,13 @@ export class uServer extends BaseServer {
         const client = this.clients[id];
         if (!client) {
           debug("upgrade attempt for closed client");
-          res.close();
+          return res.close();
         } else if (client.upgrading) {
           debug("transport has already been trying to upgrade");
-          res.close();
+          return res.close();
         } else if (client.upgraded) {
           debug("transport had already been upgraded");
-          res.close();
+          return res.close();
         } else {
           debug("upgrading existing transport");
           transport = this.createTransport(req._query.transport, req);
@@ -202,7 +206,7 @@ export class uServer extends BaseServer {
           req._query.transport,
           req,
           (errorCode, errorContext) =>
-            this.abortRequest(res, errorCode, errorContext)
+            this.abortRequest(res, errorCode, errorContext),
         );
         if (!transport) {
           return;
@@ -219,7 +223,7 @@ export class uServer extends BaseServer {
         req.getHeader("sec-websocket-key"),
         req.getHeader("sec-websocket-protocol"),
         req.getHeader("sec-websocket-extensions"),
-        context
+        context,
       );
     };
 
@@ -235,7 +239,7 @@ export class uServer extends BaseServer {
   private abortRequest(
     res: HttpResponse | ResponseWrapper,
     errorCode,
-    errorContext
+    errorContext,
   ) {
     const statusCode =
       errorCode === Server.errors.FORBIDDEN
@@ -252,7 +256,7 @@ export class uServer extends BaseServer {
       JSON.stringify({
         code: errorCode,
         message,
-      })
+      }),
     );
   }
 }

packages/engine.io/test/common.js

@@ -4,6 +4,17 @@ const { Socket } =
     ? require("engine.io-client-v3")
     : require("engine.io-client");
 
+switch (process.env.EIO_WS_ENGINE) {
+  case "uws":
+    console.log(
+      "[WARN] testing with uWebSockets.js instead of Node.js built-in HTTP server",
+    );
+    break;
+  case "eiows":
+    console.log("[WARN] testing with eiows instead of ws");
+    break;
+}
+
 /**
  * Listen shortcut that fires a callback on an ephemeral port.
  */

packages/engine.io/test/engine.io.js

@@ -93,7 +93,7 @@ describe("engine", () => {
             "Upgrade: IRC/6.9",
             "",
             "",
-          ].join("\r\n")
+          ].join("\r\n"),
         );
 
         const check = setTimeout(() => {
@@ -122,7 +122,7 @@ describe("engine", () => {
               "Upgrade: IRC/6.9",
               "",
               "",
-            ].join("\r\n")
+            ].join("\r\n"),
           );
 
           setTimeout(() => {
@@ -154,7 +154,7 @@ describe("engine", () => {
               "Upgrade: IRC/6.9",
               "",
               "",
-            ].join("\r\n")
+            ].join("\r\n"),
           );
 
           // send from client to server
@@ -198,7 +198,7 @@ describe("engine", () => {
               "Upgrade: IRC/6.9",
               "",
               "",
-            ].join("\r\n")
+            ].join("\r\n"),
           );
 
           // test that socket is still open by writing after the timeout period
@@ -245,7 +245,7 @@ describe("engine", () => {
               server.once("close", done);
               server.close();
             });
-          }
+          },
         );
       });
     });

packages/engine.io/test/middlewares.js

@@ -38,7 +38,7 @@ describe("middlewares", () => {
       });
 
       const socket = new WebSocket(
-        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`
+        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`,
       );
 
       socket.on("upgrade", (res) => {
@@ -131,7 +131,7 @@ describe("middlewares", () => {
       });
 
       const socket = new WebSocket(
-        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`
+        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`,
       );
 
       socket.addEventListener("error", () => {
@@ -169,7 +169,7 @@ describe("middlewares", () => {
       engine.use(helmet());
 
       const socket = new WebSocket(
-        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`
+        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`,
       );
 
       socket.on("upgrade", (res) => {
@@ -196,7 +196,7 @@ describe("middlewares", () => {
           resave: false,
           saveUninitialized: true,
           cookie: {},
-        })
+        }),
       );
 
       request
@@ -206,7 +206,7 @@ describe("middlewares", () => {
           expect(err).to.be(null);
           // expect(res.status).to.eql(200);
           expect(res.headers["set-cookie"][0].startsWith("connect.sid=")).to.be(
-            true
+            true,
           );
 
           if (engine.httpServer) {
@@ -225,16 +225,16 @@ describe("middlewares", () => {
           resave: false,
           saveUninitialized: true,
           cookie: {},
-        })
+        }),
       );
 
       const socket = new WebSocket(
-        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`
+        `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`,
       );
 
       socket.on("upgrade", (res) => {
         expect(res.headers["set-cookie"][0].startsWith("connect.sid=")).to.be(
-          true
+          true,
         );
 
         if (engine.httpServer) {
@@ -280,7 +280,7 @@ describe("middlewares", () => {
         });
 
         const socket = new WebSocket(
-          `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`
+          `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket`,
         );
 
         socket.addEventListener("error", () => {

packages/engine.io/test/parser.js

@@ -16,7 +16,7 @@ describe("parser", () => {
           expect(decoded.data).to.eql("€€€€");
           done();
         });
-      }
+      },
     );
   });
 });

packages/engine.io/test/server.js

@@ -143,7 +143,7 @@ describe("server", () => {
               expect(res.body.message).to.be("Thou shall not pass");
               partialDone();
             });
-        }
+        },
       );
     });
 
@@ -161,7 +161,7 @@ describe("server", () => {
           client.on("error", () => {
             done();
           });
-        }
+        },
       );
     });
 
@@ -205,6 +205,26 @@ describe("server", () => {
       });
     });
 
+    it("should prevent the client from upgrading twice", (done) => {
+      engine = listen((port) => {
+        const client = new ClientSocket(`ws://localhost:${port}`);
+
+        client.on("upgrade", () => {
+          const socket = new WebSocket(
+            `ws://localhost:${port}/engine.io/?EIO=4&transport=websocket&sid=${client.id}`,
+          );
+
+          socket.on("error", () => {});
+
+          socket.on("close", () => {
+            client.close();
+
+            done();
+          });
+        });
+      });
+    });
+
     it("should disallow `__proto__` as transport (polling)", (done) => {
       const partialDone = createPartialDone(done, 2);
 
@@ -243,7 +263,7 @@ describe("server", () => {
         });
 
         const socket = new WebSocket(
-          `ws://localhost:${port}/engine.io/?EIO=4&transport=__proto__`
+          `ws://localhost:${port}/engine.io/?EIO=4&transport=__proto__`,
         );
 
         socket.onerror = partialDone;
@@ -262,7 +282,7 @@ describe("server", () => {
             // hack-obtain sid
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`
+              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`,
             );
             done();
           });
@@ -278,7 +298,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `woot=${sid}; Path=/; HttpOnly; SameSite=Lax`
+              `woot=${sid}; Path=/; HttpOnly; SameSite=Lax`,
             );
             done();
           });
@@ -294,7 +314,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/custom; HttpOnly; SameSite=Lax`
+              `io=${sid}; Path=/custom; HttpOnly; SameSite=Lax`,
             );
             done();
           });
@@ -310,7 +330,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; SameSite=Lax`
+              `io=${sid}; SameSite=Lax`,
             );
             done();
           });
@@ -326,7 +346,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`
+              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`,
             );
             done();
           });
@@ -342,7 +362,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/; HttpOnly; SameSite=Strict`
+              `io=${sid}; Path=/; HttpOnly; SameSite=Strict`,
             );
             done();
           });
@@ -358,7 +378,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/; SameSite=Lax`
+              `io=${sid}; Path=/; SameSite=Lax`,
             );
             done();
           });
@@ -374,7 +394,7 @@ describe("server", () => {
             expect(err).to.be(null);
             const sid = res.text.match(/"sid":"([^"]+)"/)[1];
             expect(res.headers["set-cookie"][0]).to.be(
-              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`
+              `io=${sid}; Path=/; HttpOnly; SameSite=Lax`,
             );
             done();
           });
@@ -681,14 +701,14 @@ describe("server", () => {
               expect(res.body.code).to.be(3);
               expect(res.body.message).to.be("Bad request");
               expect(res.header["access-control-allow-credentials"]).to.be(
-                "true"
+                "true",
               );
               expect(res.header["access-control-allow-origin"]).to.be(
-                "http://engine.io"
+                "http://engine.io",
               );
               partialDone();
             });
-        }
+        },
       );
     });
 
@@ -817,7 +837,7 @@ describe("server", () => {
           .end((err, res) => {
             if (process.env.EIO_WS_ENGINE === "uws") {
               expect(err).to.not.be(null);
-              expect(err.message).to.be("socket hang up");
+              expect(err.status).to.be(404);
             } else {
               expect(err).to.be(null);
               // this should not work, but it is kept for backward-compatibility
@@ -1130,7 +1150,7 @@ describe("server", () => {
             expect(res.statusCode).to.eql(400);
             res.resume();
             res.on("end", done);
-          }
+          },
         );
         req.end();
       });
@@ -1174,7 +1194,7 @@ describe("server", () => {
               // OPENED readyState is expected - we are actually polling
               expect(
                 socket.transport.pollXhr[IS_CLIENT_V3 ? "xhr" : "_xhr"]
-                  .readyState
+                  .readyState,
               ).to.be(1);
 
               // 2 requests sent to the server over an unique port means
@@ -1194,7 +1214,7 @@ describe("server", () => {
             }, 50);
           });
         });
-      }
+      },
     );
 
     it("should not trigger with connection: close header", ($done) => {
@@ -1260,7 +1280,7 @@ describe("server", () => {
             done();
           }, 200);
         });
-      }
+      },
     );
 
     it(
@@ -1295,7 +1315,7 @@ describe("server", () => {
             done();
           }, 100);
         });
-      }
+      },
     );
 
     it(
@@ -1331,7 +1351,7 @@ describe("server", () => {
             });
           });
         });
-      }
+      },
     );
 
     if (IS_CLIENT_V3) {
@@ -1370,7 +1390,7 @@ describe("server", () => {
               });
             });
           });
-        }
+        },
       );
     } else {
       it(
@@ -1408,7 +1428,7 @@ describe("server", () => {
               });
             });
           });
-        }
+        },
       );
     }
 
@@ -1435,7 +1455,7 @@ describe("server", () => {
             socket.send("test");
           });
         });
-      }
+      },
     );
 
     // tests https://github.com/LearnBoost/engine.io-client/issues/207
@@ -1634,6 +1654,67 @@ describe("server", () => {
       });
     });
 
+    it("should discard the packets in the writeBuffer when stopping the server", (done) => {
+      engine = listen((port) => {
+        const clientSocket = new ClientSocket(`ws://localhost:${port}`);
+
+        clientSocket.on("data", () => {
+          done(new Error("should not happen"));
+        });
+
+        clientSocket.on("close", (reason) => {
+          expect(reason).to.eql("transport error");
+
+          clientSocket.close();
+          done();
+        });
+
+        engine.on("connection", (socket) => {
+          socket.write("hello");
+          engine.close();
+        });
+      });
+    });
+
+    it("should discard the packets in the writeBuffer when stopping the server (2)", (done) => {
+      engine = listen((port) => {
+        const clientSocket = new ClientSocket(`ws://localhost:${port}`);
+
+        clientSocket.on("data", () => {
+          done(new Error("should not happen"));
+        });
+
+        clientSocket.on("close", (reason) => {
+          expect(reason).to.eql("transport error");
+
+          clientSocket.close();
+          done();
+        });
+
+        engine.on("connection", (socket) => {
+          socket.write("hello");
+          socket.close(); // readyState is now "closing"
+          engine.close();
+        });
+      });
+    });
+
+    it("should not discard the packets in the writeBuffer when closing gracefully", (done) => {
+      engine = listen((port) => {
+        const clientSocket = new ClientSocket(`ws://localhost:${port}`);
+
+        clientSocket.on("data", (val) => {
+          expect(val).to.eql("hello");
+          done();
+        });
+
+        engine.on("connection", (socket) => {
+          socket.write("hello");
+          socket.close();
+        });
+      });
+    });
+
     describe("graceful close", () => {
       before(function () {
         if (process.env.EIO_WS_ENGINE === "uws") {
@@ -1727,7 +1808,7 @@ describe("server", () => {
         engine.on("connection", (conn) => {
           conn.on("message", (msg) => {
             done(
-              new Error("Test invalidation (message is longer than allowed)")
+              new Error("Test invalidation (message is longer than allowed)"),
             );
           });
         });
@@ -1749,7 +1830,7 @@ describe("server", () => {
         engine.on("connection", (conn) => {
           conn.on("message", (msg) => {
             done(
-              new Error("Test invalidation (message is longer than allowed)")
+              new Error("Test invalidation (message is longer than allowed)"),
             );
           });
         });
@@ -2060,7 +2141,7 @@ describe("server", () => {
           client.on("open", () => {
             client.send("a".repeat(1e6));
           });
-        }
+        },
       );
     });
 
@@ -2202,7 +2283,7 @@ describe("server", () => {
             });
           });
         });
-      }
+      },
     );
 
     it("should support chinese", (done) => {
@@ -2546,7 +2627,7 @@ describe("server", () => {
                 j,
                 ((value) => {
                   j++;
-                })(j)
+                })(j),
               );
             }
 
@@ -2585,7 +2666,7 @@ describe("server", () => {
                 j,
                 ((value) => {
                   j++;
-                })(j)
+                })(j),
               );
             }
 
@@ -2999,7 +3080,7 @@ describe("server", () => {
               done();
             });
           });
-        }
+        },
       );
     });
   });
@@ -3031,7 +3112,7 @@ describe("server", () => {
               done();
             });
           });
-        }
+        },
       );
     });
   });
@@ -3174,11 +3255,11 @@ describe("server", () => {
                     .on("error", done)
                     .on("end", done)
                     .resume();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
 
@@ -3212,11 +3293,11 @@ describe("server", () => {
                     .on("error", done)
                     .on("end", done)
                     .resume();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
 
@@ -3250,11 +3331,11 @@ describe("server", () => {
                 (res) => {
                   expect(res.headers["content-encoding"]).to.equal("gzip");
                   done();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
 
@@ -3284,11 +3365,11 @@ describe("server", () => {
                 (res) => {
                   expect(res.headers["content-encoding"]).to.be(undefined);
                   done();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
 
@@ -3318,11 +3399,11 @@ describe("server", () => {
                 (res) => {
                   expect(res.headers["content-encoding"]).to.be(undefined);
                   done();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
 
@@ -3352,11 +3433,11 @@ describe("server", () => {
                 (res) => {
                   expect(res.headers["content-encoding"]).to.be(undefined);
                   done();
-                }
+                },
               );
-            }
+            },
           );
-        }
+        },
       );
     });
   });
@@ -3599,20 +3680,20 @@ describe("server", () => {
               expect(res.status).to.be(204);
               expect(res.body).to.be.empty();
               expect(res.header["access-control-allow-origin"]).to.be(
-                "http://engine.io"
+                "http://engine.io",
               );
               expect(res.header["access-control-allow-methods"]).to.be(
-                "GET,HEAD,PUT,PATCH,POST,DELETE"
+                "GET,HEAD,PUT,PATCH,POST,DELETE",
               );
               expect(res.header["access-control-allow-headers"]).to.be(
-                "my-header"
+                "my-header",
               );
               expect(res.header["access-control-allow-credentials"]).to.be(
-                "true"
+                "true",
               );
               done();
             });
-        }
+        },
       );
     });
 
@@ -3629,20 +3710,20 @@ describe("server", () => {
               expect(res.status).to.be(200);
               expect(res.body).to.be.empty();
               expect(res.header["access-control-allow-origin"]).to.be(
-                "http://engine.io"
+                "http://engine.io",
               );
               expect(res.header["access-control-allow-methods"]).to.be(
-                undefined
+                undefined,
               );
               expect(res.header["access-control-allow-headers"]).to.be(
-                undefined
+                undefined,
               );
               expect(res.header["access-control-allow-credentials"]).to.be(
-                "true"
+                "true",
               );
               done();
             });
-        }
+        },
       );
     });
 
@@ -3663,14 +3744,14 @@ describe("server", () => {
               expect(res.status).to.be(204);
               expect(res.body).to.be.empty();
               expect(res.header["access-control-allow-origin"]).to.be(
-                undefined
+                undefined,
               );
               expect(res.header["access-control-allow-credentials"]).to.be(
-                undefined
+                undefined,
               );
               done();
             });
-        }
+        },
       );
     });
 
@@ -3697,24 +3778,24 @@ describe("server", () => {
               expect(res.status).to.be(200);
               expect(res.body).to.be.empty();
               expect(res.header["access-control-allow-origin"]).to.be(
-                "http://good-domain.com"
+                "http://good-domain.com",
               );
               expect(res.header["access-control-allow-methods"]).to.be(
-                "GET,PUT,POST"
+                "GET,PUT,POST",
               );
               expect(res.header["access-control-allow-headers"]).to.be(
-                "my-header"
+                "my-header",
               );
               expect(res.header["access-control-expose-headers"]).to.be(
-                "my-exposed-header"
+                "my-exposed-header",
               );
               expect(res.header["access-control-allow-credentials"]).to.be(
-                "true"
+                "true",
               );
               expect(res.header["access-control-max-age"]).to.be("123");
               done();
             });
-        }
+        },
       );
     });
 
@@ -3739,7 +3820,7 @@ describe("server", () => {
             client.close();
             done();
           });
-        }
+        },
       );
     });
   });
@@ -3767,7 +3848,7 @@ describe("server", () => {
               done();
             });
           });
-        }
+        },
       );
     });
   });

packages/engine.io/test/webtransport.mjs

@@ -31,7 +31,7 @@ async function setupServer(opts, cb) {
     [{ shortName: "CN", value: "localhost" }],
     {
       days: 14, // the total length of the validity period MUST NOT exceed two weeks (https://w3c.github.io/webtransport/#custom-certificate-requirements)
-    }
+    },
   );
 
   const engine = new eio.Server(opts);
@@ -76,7 +76,7 @@ function setup(opts, cb) {
             value: certificate.hash,
           },
         ],
-      }
+      },
     );
 
     await client.ready;
@@ -106,7 +106,7 @@ describe("WebTransport", () => {
     setupServer({}, async ({ engine, h3Server, certificate }) => {
       const partialDone = createPartialDone(
         () => success(engine, h3Server, done),
-        2
+        2,
       );
 
       engine.on("connection", (socket) => {
@@ -123,7 +123,7 @@ describe("WebTransport", () => {
               value: certificate.hash,
             },
           ],
-        }
+        },
       );
 
       await client.ready;
@@ -188,7 +188,7 @@ describe("WebTransport", () => {
                     value: certificate.hash,
                   },
                 ],
-              }
+              },
             );
 
             await client.ready;
@@ -216,14 +216,14 @@ describe("WebTransport", () => {
 
             await writer.write(Uint8Array.of(31));
             await writer.write(
-              TEXT_ENCODER.encode(`0{"sid":"${payload.sid}"}`)
+              TEXT_ENCODER.encode(`0{"sid":"${payload.sid}"}`),
             );
             await writer.write(Uint8Array.of(6));
             await writer.write(TEXT_ENCODER.encode(`2probe`));
             await writer.write(Uint8Array.of(1));
             await writer.write(TEXT_ENCODER.encode(`5`));
           });
-      }
+      },
     );
   });
 
@@ -242,7 +242,7 @@ describe("WebTransport", () => {
                 value: certificate.hash,
               },
             ],
-          }
+          },
         );
 
         await client.ready;
@@ -250,7 +250,7 @@ describe("WebTransport", () => {
         client.closed.then(() => {
           success(engine, h3Server, done);
         });
-      }
+      },
     );
   });
 
@@ -269,7 +269,7 @@ describe("WebTransport", () => {
                 value: certificate.hash,
               },
             ],
-          }
+          },
         );
 
         await client.ready;
@@ -281,7 +281,7 @@ describe("WebTransport", () => {
         client.closed.then(() => {
           success(engine, h3Server, done);
         });
-      }
+      },
     );
   });
 
@@ -304,7 +304,7 @@ describe("WebTransport", () => {
         }
 
         success(engine, h3Server, done);
-      }
+      },
     );
   });
 
@@ -322,7 +322,7 @@ describe("WebTransport", () => {
         });
 
         client.closed.then(() => success(engine, h3Server, partialDone));
-      }
+      },
     );
   });
 
@@ -440,7 +440,7 @@ describe("WebTransport", () => {
 
       const header = await reader.read();
       expect(header.value).to.eql(
-        Uint8Array.of(255, 0, 0, 0, 0, 0, 15, 66, 64)
+        Uint8Array.of(255, 0, 0, 0, 0, 0, 15, 66, 64),
       );
 
       const chunk1 = await reader.read();

packages/socket.io-adapter/lib/cluster-adapter.ts

@@ -203,7 +203,7 @@ export abstract class ClusterAdapter extends Adapter {
       "[%s] new event of type %d from %s",
       this.uid,
       message.type,
-      message.uid
+      message.uid,
     );
 
     switch (message.type) {
@@ -217,7 +217,7 @@ export abstract class ClusterAdapter extends Adapter {
               debug(
                 "[%s] waiting for %d client acknowledgements",
                 this.uid,
-                clientCount
+                clientCount,
               );
               this.publishResponse(message.uid, {
                 type: MessageType.BROADCAST_CLIENT_COUNT,
@@ -231,7 +231,7 @@ export abstract class ClusterAdapter extends Adapter {
               debug(
                 "[%s] received acknowledgement with value %j",
                 this.uid,
-                arg
+                arg,
               );
               this.publishResponse(message.uid, {
                 type: MessageType.BROADCAST_ACK,
@@ -240,7 +240,7 @@ export abstract class ClusterAdapter extends Adapter {
                   packet: arg,
                 },
               });
-            }
+            },
           );
         } else {
           const packet = message.data.packet;
@@ -264,7 +264,7 @@ export abstract class ClusterAdapter extends Adapter {
       case MessageType.DISCONNECT_SOCKETS:
         super.disconnectSockets(
           decodeOptions(message.data.opts),
-          message.data.close
+          message.data.close,
         );
         break;
 
@@ -272,7 +272,7 @@ export abstract class ClusterAdapter extends Adapter {
         debug(
           "[%s] calling fetchSockets with opts %j",
           this.uid,
-          message.data.opts
+          message.data.opts,
         );
         super
           .fetchSockets(decodeOptions(message.data.opts))
@@ -356,7 +356,7 @@ export abstract class ClusterAdapter extends Adapter {
       "[%s] received response %s to request %s",
       this.uid,
       response.type,
-      requestId
+      requestId,
     );
 
     switch (response.type) {
@@ -381,7 +381,7 @@ export abstract class ClusterAdapter extends Adapter {
 
         request.current++;
         response.data.sockets.forEach((socket) =>
-          request.responses.push(socket)
+          request.responses.push(socket),
         );
 
         if (request.current === request.expected) {
@@ -433,7 +433,7 @@ export abstract class ClusterAdapter extends Adapter {
         return debug(
           "[%s] error while broadcasting message: %s",
           this.uid,
-          e.message
+          e.message,
         );
       }
     }
@@ -453,7 +453,7 @@ export abstract class ClusterAdapter extends Adapter {
   private addOffsetIfNecessary(
     packet: any,
     opts: BroadcastOptions,
-    offset: Offset
+    offset: Offset,
   ) {
     if (!this.nsp.server.opts.connectionStateRecovery) {
       return;
@@ -473,7 +473,7 @@ export abstract class ClusterAdapter extends Adapter {
     packet: any,
     opts: BroadcastOptions,
     clientCountCallback: (clientCount: number) => void,
-    ack: (...args: any[]) => void
+    ack: (...args: any[]) => void,
   ) {
     const onlyLocal = opts?.flags?.local;
     if (!onlyLocal) {
@@ -582,8 +582,8 @@ export abstract class ClusterAdapter extends Adapter {
         if (storedRequest) {
           reject(
             new Error(
-              `timeout reached: only ${storedRequest.current} responses received out of ${storedRequest.expected}`
-            )
+              `timeout reached: only ${storedRequest.current} responses received out of ${storedRequest.expected}`,
+            ),
           );
           this.requests.delete(requestId);
         }
@@ -627,7 +627,7 @@ export abstract class ClusterAdapter extends Adapter {
     debug(
       '[%s] waiting for %d responses to "serverSideEmit" request',
       this.uid,
-      expectedResponseCount
+      expectedResponseCount,
     );
 
     if (expectedResponseCount <= 0) {
@@ -641,9 +641,9 @@ export abstract class ClusterAdapter extends Adapter {
       if (storedRequest) {
         ack(
           new Error(
-            `timeout reached: only ${storedRequest.current} responses received out of ${storedRequest.expected}`
+            `timeout reached: only ${storedRequest.current} responses received out of ${storedRequest.expected}`,
           ),
-          storedRequest.responses
+          storedRequest.responses,
         );
         this.requests.delete(requestId);
       }
@@ -669,7 +669,7 @@ export abstract class ClusterAdapter extends Adapter {
   }
 
   protected publish(
-    message: DistributiveOmit<ClusterMessage, "nsp" | "uid">
+    message: DistributiveOmit<ClusterMessage, "nsp" | "uid">,
   ): void {
     this.publishAndReturnOffset(message).catch((err) => {
       debug("[%s] error while publishing message: %s", this.uid, err);
@@ -677,7 +677,7 @@ export abstract class ClusterAdapter extends Adapter {
   }
 
   protected publishAndReturnOffset(
-    message: DistributiveOmit<ClusterMessage, "nsp" | "uid">
+    message: DistributiveOmit<ClusterMessage, "nsp" | "uid">,
   ) {
     (message as ClusterMessage).uid = this.uid;
     (message as ClusterMessage).nsp = this.nsp.name;
@@ -695,14 +695,14 @@ export abstract class ClusterAdapter extends Adapter {
 
   protected publishResponse(
     requesterUid: ServerId,
-    response: Omit<ClusterResponse, "nsp" | "uid">
+    response: Omit<ClusterResponse, "nsp" | "uid">,
   ) {
     (response as ClusterResponse).uid = this.uid;
     (response as ClusterResponse).nsp = this.nsp.name;
     this.doPublishResponse(requesterUid, response as ClusterResponse).catch(
       (err) => {
         debug("[%s] error while publishing response: %s", this.uid, err);
-      }
+      },
     );
   }
 
@@ -715,7 +715,7 @@ export abstract class ClusterAdapter extends Adapter {
    */
   protected abstract doPublishResponse(
     requesterUid: ServerId,
-    response: ClusterResponse
+    response: ClusterResponse,
   ): Promise<void>;
 }
 
@@ -742,7 +742,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
         heartbeatInterval: 5_000,
         heartbeatTimeout: 10_000,
       },
-      opts
+      opts,
     );
     this.cleanupTimer = setInterval(() => {
       const now = Date.now();
@@ -798,7 +798,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
       "[%s] new event of type %d from %s",
       this.uid,
       message.type,
-      message.uid
+      message.uid,
     );
 
     switch (message.type) {
@@ -846,7 +846,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
     debug(
       '[%s] waiting for %d responses to "serverSideEmit" request',
       this.uid,
-      expectedResponseCount
+      expectedResponseCount,
     );
 
     if (expectedResponseCount <= 0) {
@@ -860,9 +860,9 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
       if (storedRequest) {
         ack(
           new Error(
-            `timeout reached: missing ${storedRequest.missingUids.size} responses`
+            `timeout reached: missing ${storedRequest.missingUids.size} responses`,
           ),
-          storedRequest.responses
+          storedRequest.responses,
         );
         this.customRequests.delete(requestId);
       }
@@ -911,8 +911,8 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
         if (storedRequest) {
           reject(
             new Error(
-              `timeout reached: missing ${storedRequest.missingUids.size} responses`
-            )
+              `timeout reached: missing ${storedRequest.missingUids.size} responses`,
+            ),
           );
           this.customRequests.delete(requestId);
         }
@@ -944,7 +944,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
       "[%s] received response %s to request %s",
       this.uid,
       response.type,
-      requestId
+      requestId,
     );
 
     switch (response.type) {
@@ -956,7 +956,7 @@ export abstract class ClusterAdapterWithHeartbeat extends ClusterAdapter {
         }
 
         (response.data.sockets as any[]).forEach((socket) =>
-          request.responses.push(socket)
+          request.responses.push(socket),
         );
 
         request.missingUids.delete(response.uid);

packages/socket.io-adapter/lib/contrib/yeast.ts

@@ -3,7 +3,7 @@
 
 const alphabet =
     "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_".split(
-      ""
+      "",
     ),
   length = 64,
   map = {};

packages/socket.io-adapter/lib/in-memory-adapter.ts

@@ -198,7 +198,7 @@ export class Adapter extends EventEmitter {
     packet: any,
     opts: BroadcastOptions,
     clientCountCallback: (clientCount: number) => void,
-    ack: (...args: any[]) => void
+    ack: (...args: any[]) => void,
   ) {
     const flags = opts.flags || {};
     const packetOpts = {
@@ -375,7 +375,7 @@ export class Adapter extends EventEmitter {
    */
   public serverSideEmit(packet: any[]): void {
     console.warn(
-      "this adapter does not support the serverSideEmit() functionality"
+      "this adapter does not support the serverSideEmit() functionality",
     );
   }
 
@@ -391,7 +391,7 @@ export class Adapter extends EventEmitter {
    */
   public restoreSession(
     pid: PrivateSessionId,
-    offset: string
+    offset: string,
   ): Promise<Session> {
     return null;
   }
@@ -444,7 +444,7 @@ export class SessionAwareAdapter extends Adapter {
 
   override restoreSession(
     pid: PrivateSessionId,
-    offset: string
+    offset: string,
   ): Promise<Session> {
     const session = this.sessions.get(pid);
     if (!session) {
@@ -500,7 +500,7 @@ export class SessionAwareAdapter extends Adapter {
 
 function shouldIncludePacket(
   sessionRooms: Room[],
-  opts: BroadcastOptions
+  opts: BroadcastOptions,
 ): boolean {
   const included =
     opts.rooms.size === 0 || sessionRooms.some((room) => opts.rooms.has(room));

packages/socket.io-adapter/package.json

@@ -21,7 +21,7 @@
     "ws": "~8.17.1"
   },
   "scripts": {
-    "compile": "tsc",
+    "compile": "rimraf ./dist && tsc",
     "test": "npm run format:check && npm run compile && nyc mocha --require ts-node/register test/*.ts",
     "format:check": "prettier --parser typescript --check 'lib/**/*.ts' 'test/**/*.ts'",
     "format:fix": "prettier --parser typescript --write 'lib/**/*.ts' 'test/**/*.ts'",

packages/socket.io-adapter/test/cluster-adapter.ts

@@ -16,7 +16,10 @@ const NODES_COUNT = 3;
 class EventEmitterAdapter extends ClusterAdapterWithHeartbeat {
   private offset = 1;
 
-  constructor(nsp, readonly eventBus) {
+  constructor(
+    nsp,
+    readonly eventBus,
+  ) {
     super(nsp, {});
     this.eventBus.on("message", (message) => {
       this.onMessage(message as ClusterMessage);
@@ -30,7 +33,7 @@ class EventEmitterAdapter extends ClusterAdapterWithHeartbeat {
 
   protected doPublishResponse(
     requesterUid: string,
-    response: ClusterResponse
+    response: ClusterResponse,
   ): Promise<void> {
     this.eventBus.emit("message", response);
     return Promise.resolve();

packages/socket.io-adapter/test/index.ts

@@ -153,7 +153,7 @@ describe("socket.io-adapter", () => {
               expect(opts.wsPreEncodedFrame.length).to.eql(2);
               expect(opts.wsPreEncodedFrame[0]).to.eql(Buffer.from([129, 4]));
               expect(opts.wsPreEncodedFrame[1]).to.eql(
-                Buffer.from([52, 49, 50, 51])
+                Buffer.from([52, 49, 50, 51]),
               );
             },
           },
@@ -352,7 +352,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(),
-        }
+        },
       );
 
       const offset = packetData[1];
@@ -398,7 +398,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -410,7 +410,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -422,7 +422,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(["r1"]),
           except: new Set(),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -434,7 +434,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(["r2"]),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -446,7 +446,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(["r3"]),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -459,7 +459,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -471,7 +471,7 @@ describe("socket.io-adapter", () => {
         {
           rooms: new Set(),
           except: new Set(),
-        }
+        },
       );
 
       adapter.broadcast(
@@ -486,7 +486,7 @@ describe("socket.io-adapter", () => {
           flags: {
             volatile: true,
           },
-        }
+        },
       );
 
       const offset = packetData[1];

packages/socket.io-client/CHANGELOG.md

@@ -1,69 +1,51 @@
 # History
 
-## 2024
-
-- [4.7.5](#475-2024-03-14) (Mar 2024)
-- [4.7.4](#474-2024-01-12) (Jan 2024)
-- [4.7.3](#473-2024-01-03) (Jan 2024)
-
-## 2023
-
-- [4.7.2](#472-2023-08-02) (Aug 2023)
-- [4.7.1](#471-2023-06-28) (Jun 2023)
-- [4.7.0](#470-2023-06-22) (Jun 2023)
-- [4.6.2](#462-2023-05-31) (May 2023)
-- [4.6.1](#461-2023-02-20) (Feb 2023)
-- [4.6.0](#460-2023-02-07) (Feb 2023)
-
-## 2022
-
-- [4.5.4](#454-2022-11-22) (Nov 2022)
-- [4.5.3](#453-2022-10-15) (Oct 2022)
-- [4.5.2](#452-2022-09-02) (Sep 2022)
-- [2.5.0](#250-2022-06-26) (Jun 2022) (from the [2.x](https://github.com/socketio/socket.io-client/tree/2.x) branch)
-- [4.5.1](#451-2022-05-17) (May 2022)
-- [4.5.0](#450-2022-04-23) (Apr 2022)
-- [4.4.1](#441-2022-01-06) (Jan 2022)
-
-## 2021
-
-- [4.4.0](#440-2021-11-18) (Nov 2021)
-- [4.3.2](#432-2021-10-16) (Oct 2021)
-- [4.3.1](#431-2021-10-15) (Oct 2021)
-- [4.3.0](#430-2021-10-14) (Oct 2021)
-- [4.2.0](#420-2021-08-30) (Aug 2021)
-- [4.1.3](#413-2021-07-10) (Jul 2021)
-- [4.1.2](#412-2021-05-17) (May 2021)
-- [4.1.1](#411-2021-05-11) (May 2021)
-- [4.1.0](#410-2021-05-11) (May 2021)
-- [4.0.2](#402-2021-05-06) (May 2021)
-- [4.0.1](#401-2021-03-31) (Mar 2021)
-- [3.1.3](#313-2021-03-12) (Mar 2021) (from the [3.1.x](https://github.com/socketio/socket.io-client/tree/3.1.x) branch)
-- [**4.0.0**](#400-2021-03-10) (Mar 2021)
-- [3.1.2](#312-2021-02-26) (Feb 2021)
-- [3.1.1](#311-2021-02-03) (Feb 2021)
-- [3.1.0](#310-2021-01-15) (Jan 2021)
-- [3.0.5](#305-2021-01-05) (Jan 2021)
-- [2.4.0](#240-2021-01-04) (Jan 2021) (from the [2.x](https://github.com/socketio/socket.io-client/tree/2.x) branch)
-
-## 2020
-
-- [3.0.4](#304-2020-12-07) (Dec 2020)
-- [3.0.3](#303-2020-11-19) (Nov 2020)
-- [3.0.2](#302-2020-11-17) (Nov 2020)
-- [3.0.1](#301-2020-11-09) (Nov 2020)
-- [**3.0.0**](#300-2020-11-05) (Nov 2020)
-- [2.3.1](#231-2020-09-30) (Sep 2020)
-
-## 2019
-
-- [2.3.0](#230-2019-09-20) (Sep 2019)
-
-## 2018
-
-- [2.2.0](#220-2018-11-29) (Nov 2018)
-- [2.1.1](#211-2018-05-17) (May 2018)
-- [2.1.0](#210-2018-03-29) (Mar 2018)
+| Version                                                                                                     | Release date   | Bundle size (UMD min+gzip) |
+|-------------------------------------------------------------------------------------------------------------|----------------|----------------------------|
+| [4.7.5](#475-2024-03-14)                                                                                    | March 2024     | `14.6 KB`                  |
+| [4.7.4](#474-2024-01-12)                                                                                    | January 2024   | `14.5 KB`                  |
+| [4.7.3](#473-2024-01-03)                                                                                    | January 2024   | `14.5 KB`                  |
+| [4.7.2](#472-2023-08-02)                                                                                    | August 2023    | `14.5 KB`                  |
+| [4.7.1](#471-2023-06-28)                                                                                    | June 2023      | `14.1 KB`                  |
+| [4.7.0](#470-2023-06-22)                                                                                    | June 2023      | `14.0 KB`                  |
+| [4.6.2](#462-2023-05-31)                                                                                    | May 2023       | `13.4 KB`                  |
+| [4.6.1](#461-2023-02-20)                                                                                    | February 2023  | `13.3 KB`                  |
+| [4.6.0](#460-2023-02-07)                                                                                    | February 2023  | `13.3 KB`                  |
+| [4.5.4](#454-2022-11-22)                                                                                    | November 2022  | `12.8 KB`                  |
+| [4.5.3](#453-2022-10-15)                                                                                    | October 2022   | `12.8 KB`                  |
+| [4.5.2](#452-2022-09-02)                                                                                    | September 2022 | `12.7 KB`                  |
+| [2.5.0](#250-2022-06-26) (from the [2.x](https://github.com/socketio/socket.io-client/tree/2.x) branch)     | June 2022      | `18.8 KB`                  |
+| [4.5.1](#451-2022-05-17)                                                                                    | May 2022       | `12.7 KB`                  |
+| [4.5.0](#450-2022-04-23)                                                                                    | April 2022     | `12.7 KB`                  |
+| [4.4.1](#441-2022-01-06)                                                                                    | January 2022   | `12.3 KB`                  |
+| [4.4.0](#440-2021-11-18)                                                                                    | November 2021  | `12.3 KB`                  |
+| [4.3.2](#432-2021-10-16)                                                                                    | October 2021   | `12.1 KB`                  |
+| [4.3.1](#431-2021-10-15)                                                                                    | October 2021   | `12.1 KB`                  |
+| [4.3.0](#430-2021-10-14)                                                                                    | October 2021   | `12.1 KB`                  |
+| [4.2.0](#420-2021-08-30)                                                                                    | August 2021    | `15.2 KB`                  |
+| [4.1.3](#413-2021-07-10)                                                                                    | July 2021      | `14.9 KB`                  |
+| [4.1.2](#412-2021-05-17)                                                                                    | May 2021       | `14.9 KB`                  |
+| [4.1.1](#411-2021-05-11)                                                                                    | May 2021       | `14.9 KB`                  |
+| [4.1.0](#410-2021-05-11)                                                                                    | May 2021       | `14.9 KB`                  |
+| [4.0.2](#402-2021-05-06)                                                                                    | May 2021       | `14.9 KB`                  |
+| [4.0.1](#401-2021-03-31)                                                                                    | March 2021     | `14.9 KB`                  |
+| [3.1.3](#313-2021-03-12) (from the [3.1.x](https://github.com/socketio/socket.io-client/tree/3.1.x) branch) | March 2021     | `14.6 KB`                  |
+| [**4.0.0**](#400-2021-03-10)                                                                                | March 2021     | `14.9 KB`                  |
+| [3.1.2](#312-2021-02-26)                                                                                    | February 2021  | `14.6 KB`                  |
+| [3.1.1](#311-2021-02-03)                                                                                    | February 2021  | `14.5 KB`                  |
+| [3.1.0](#310-2021-01-15)                                                                                    | January 2021   | `14.5 KB`                  |
+| [3.0.5](#305-2021-01-05)                                                                                    | January 2021   | `14.5 KB`                  |
+| [2.4.0](#240-2021-01-04) (from the [2.x](https://github.com/socketio/socket.io-client/tree/2.x) branch)     | January 2021   | `18.8 KB`                  |
+| [3.0.4](#304-2020-12-07)                                                                                    | December 2020  | `14.6 KB`                  |
+| [3.0.3](#303-2020-11-19)                                                                                    | November 2020  | `14.5 KB`                  |
+| [3.0.2](#302-2020-11-17)                                                                                    | November 2020  | `14.5 KB`                  |
+| [3.0.1](#301-2020-11-09)                                                                                    | November 2020  | `14.7 KB`                  |
+| [**3.0.0**](#300-2020-11-05)                                                                                | November 2020  | `14.6 KB`                  |
+| [2.3.1](#231-2020-09-30)                                                                                    | September 2020 | `18.8 KB`                  |
+| [2.3.0](#230-2019-09-20)                                                                                    | September 2019 | `19.6 KB`                  |
+| [2.2.0](#220-2018-11-29)                                                                                    | November 2018  | `18.6 KB`                  |
+| [2.1.1](#211-2018-05-17)                                                                                    | May 2018       | `18.7 KB`                  |
+| [2.1.0](#210-2018-03-29)                                                                                    | March 2018     | `18.7 KB`                  |
 
 
 # Release notes

packages/socket.io-client/lib/index.ts

@@ -24,12 +24,12 @@ const cache: Record<string, Manager> = {};
  */
 function lookup(opts?: Partial<ManagerOptions & SocketOptions>): Socket;
 function lookup(
-  uri: string,
-  opts?: Partial<ManagerOptions & SocketOptions>
+  uri?: string,
+  opts?: Partial<ManagerOptions & SocketOptions>,
 ): Socket;
 function lookup(
   uri?: string | Partial<ManagerOptions & SocketOptions>,
-  opts?: Partial<ManagerOptions & SocketOptions>
+  opts?: Partial<ManagerOptions & SocketOptions>,
 ): Socket {
   if (typeof uri === "object") {
     opts = uri;

packages/socket.io-client/lib/manager.ts

@@ -100,7 +100,7 @@ interface ManagerReservedEvents {
 
 export class Manager<
   ListenEvents extends EventsMap = DefaultEventsMap,
-  EmitEvents extends EventsMap = ListenEvents
+  EmitEvents extends EventsMap = ListenEvents,
 > extends Emitter<{}, {}, ManagerReservedEvents> {
   /**
    * The Engine.IO client instance
@@ -152,11 +152,11 @@ export class Manager<
   constructor(uri?: string, opts?: Partial<ManagerOptions>);
   constructor(
     uri?: string | Partial<ManagerOptions>,
-    opts?: Partial<ManagerOptions>
+    opts?: Partial<ManagerOptions>,
   );
   constructor(
     uri?: string | Partial<ManagerOptions>,
-    opts?: Partial<ManagerOptions>
+    opts?: Partial<ManagerOptions>,
   ) {
     super();
     if (uri && "object" === typeof uri) {
@@ -201,6 +201,9 @@ export class Manager<
   public reconnection(v?: boolean): this | boolean {
     if (!arguments.length) return this._reconnection;
     this._reconnection = !!v;
+    if (!v) {
+      this.skipReconnect = true;
+    }
     return this;
   }
 
@@ -405,7 +408,7 @@ export class Manager<
       on(socket, "error", this.onerror.bind(this)),
       on(socket, "close", this.onclose.bind(this)),
       // @ts-ignore
-      on(this.decoder, "decoded", this.ondecoded.bind(this))
+      on(this.decoder, "decoded", this.ondecoded.bind(this)),
     );
   }
 
@@ -531,7 +534,6 @@ export class Manager<
     this.skipReconnect = true;
     this._reconnecting = false;
     this.onclose("forced close");
-    if (this.engine) this.engine.close();
   }
 
   /**
@@ -544,7 +546,11 @@ export class Manager<
   }
 
   /**
-   * Called upon engine close.
+   * Called when:
+   *
+   * - the low-level engine is closed
+   * - the parser encountered a badly formatted packet
+   * - all sockets are disconnected
    *
    * @private
    */
@@ -552,6 +558,7 @@ export class Manager<
     debug("closed due to %s", reason);
 
     this.cleanup();
+    this.engine?.close();
     this.backoff.reset();
     this._readyState = "closed";
     this.emitReserved("close", reason, description);

packages/socket.io-client/lib/on.ts

@@ -3,7 +3,7 @@ import { Emitter } from "@socket.io/component-emitter";
 export function on(
   obj: Emitter<any, any>,
   ev: string,
-  fn: (err?: any) => any
+  fn: (err?: any) => any,
 ): VoidFunction {
   obj.on(ev, fn);
   return function subDestroy(): void {

packages/socket.io-client/lib/socket.ts

@@ -116,7 +116,7 @@ interface SocketReservedEvents {
   connect_error: (err: Error) => void;
   disconnect: (
     reason: Socket.DisconnectReason,
-    description?: DisconnectDescription
+    description?: DisconnectDescription,
   ) => void;
 }
 
@@ -146,7 +146,7 @@ interface SocketReservedEvents {
  */
 export class Socket<
   ListenEvents extends EventsMap = DefaultEventsMap,
-  EmitEvents extends EventsMap = ListenEvents
+  EmitEvents extends EventsMap = ListenEvents,
 > extends Emitter<ListenEvents, EmitEvents, SocketReservedEvents> {
   public readonly io: Manager<ListenEvents, EmitEvents>;
 
@@ -440,16 +440,13 @@ export class Socket<
       packet.id = id;
     }
 
-    const isTransportWritable =
-      this.io.engine &&
-      this.io.engine.transport &&
-      this.io.engine.transport.writable;
+    const isTransportWritable = this.io.engine?.transport?.writable;
+    const isConnected = this.connected && !this.io.engine?._hasPingExpired();
 
-    const discardPacket =
-      this.flags.volatile && (!isTransportWritable || !this.connected);
+    const discardPacket = this.flags.volatile && !isTransportWritable;
     if (discardPacket) {
       debug("discard packet as the transport is not currently writable");
-    } else if (this.connected) {
+    } else if (isConnected) {
       this.notifyOutgoingListeners(packet);
       this.packet(packet);
     } else {
@@ -554,7 +551,7 @@ export class Socket<
           debug(
             "packet [%d] is discarded after %d tries",
             packet.id,
-            packet.tryCount
+            packet.tryCount,
           );
           this._queue.shift();
           if (ack) {
@@ -591,7 +588,7 @@ export class Socket<
     if (packet.pending && !force) {
       debug(
         "packet [%d] has already been sent and is waiting for an ack",
-        packet.id
+        packet.id,
       );
       return;
     }
@@ -665,7 +662,7 @@ export class Socket<
    */
   private onclose(
     reason: Socket.DisconnectReason,
-    description?: DisconnectDescription
+    description?: DisconnectDescription,
   ): void {
     debug("close (%s)", reason);
     this.connected = false;
@@ -683,7 +680,7 @@ export class Socket<
   private _clearAcks() {
     Object.keys(this.acks).forEach((id) => {
       const isBuffered = this.sendBuffer.some(
-        (packet) => String(packet.id) === id
+        (packet) => String(packet.id) === id,
       );
       if (!isBuffered) {
         // note: handlers that do not accept an error as first argument are ignored here
@@ -716,8 +713,8 @@ export class Socket<
           this.emitReserved(
             "connect_error",
             new Error(
-              "It seems you are trying to reach a Socket.IO server in v2.x with a v3.x client, but they are not compatible (more information here: https://socket.io/docs/v3/migrating-from-2-x-to-3-0/)"
-            )
+              "It seems you are trying to reach a Socket.IO server in v2.x with a v3.x client, but they are not compatible (more information here: https://socket.io/docs/v3/migrating-from-2-x-to-3-0/)",
+            ),
           );
         }
         break;
@@ -967,7 +964,7 @@ export class Socket<
    * @returns self
    */
   public timeout(
-    timeout: number
+    timeout: number,
   ): Socket<ListenEvents, DecorateAcknowledgements<EmitEvents>> {
     this.flags.timeout = timeout;
     return this;

packages/socket.io-client/lib/url.ts

@@ -39,7 +39,7 @@ type ParsedUrl = {
 export function url(
   uri: string | ParsedUrl,
   path: string = "",
-  loc?: Location
+  loc?: Location,
 ): ParsedUrl {
   let obj = uri as ParsedUrl;
 

packages/socket.io-client/package.json

@@ -47,16 +47,17 @@
   "dependencies": {
     "@socket.io/component-emitter": "~3.1.0",
     "debug": "~4.3.2",
-    "engine.io-client": "~6.5.2",
+    "engine.io-client": "~6.6.0",
     "socket.io-parser": "~4.2.4"
   },
   "scripts": {
     "compile": "rimraf ./build && tsc && tsc -p tsconfig.esm.json && ./postcompile.sh",
     "test": "npm run format:check && npm run compile && if test \"$BROWSERS\" = \"1\" ; then npm run test:browser; else npm run test:node; fi",
-    "test:node": "mocha --require ts-node/register --reporter dot --require test/support/hooks.ts --timeout 5000 --exit test/index.ts",
+    "test:node": "mocha --require ts-node/register --require test/support/hooks.ts --exit test/index.ts",
     "test:browser": "ts-node test/browser-runner.ts",
     "test:types": "tsd",
     "build": "rollup -c support/rollup.config.umd.js && rollup -c support/rollup.config.esm.js && rollup -c support/rollup.config.umd.msgpack.js",
+    "bundle-size": "node support/bundle-size.js",
     "format:check": "prettier --check \"*.js\" \"lib/**/*.ts\" \"test/**/*.ts\" \"support/**/*.js\"",
     "format:fix": "prettier --write \"*.js\" \"lib/**/*.ts\" \"test/**/*.ts\" \"support/**/*.js\"",
     "prepack": "npm run compile"

packages/socket.io-client/support/bundle-size.js

@@ -0,0 +1,35 @@
+const { resolve } = require("node:path");
+const { readFile } = require("node:fs/promises");
+const { gzipSync, brotliCompressSync } = require("node:zlib");
+
+const bundles = [
+  {
+    name: "UMD bundle",
+    path: "dist/socket.io.min.js",
+  },
+  {
+    name: "ESM bundle",
+    path: "dist/socket.io.esm.min.js",
+  },
+];
+
+function format(size) {
+  return (size / 1024).toFixed(1);
+}
+
+async function main() {
+  for (const bundle of bundles) {
+    const path = resolve(bundle.path);
+    const content = await readFile(path);
+    const gzip = gzipSync(content);
+    const brotli = brotliCompressSync(content);
+
+    console.log(`${bundle.name}`);
+    console.log(`min: ${format(content.length)} KB`);
+    console.log(`min+gzip: ${format(gzip.length)} KB`);
+    console.log(`min+br: ${format(brotli.length)} KB`);
+    console.log();
+  }
+}
+
+main();

packages/socket.io-client/support/rollup.config.esm.js

@@ -15,7 +15,15 @@ module.exports = {
     file: "./dist/socket.io.esm.min.js",
     format: "esm",
     sourcemap: true,
-    plugins: [terser()],
+    plugins: [
+      terser({
+        mangle: {
+          properties: {
+            regex: /^_/,
+          },
+        },
+      }),
+    ],
     banner,
   },
   plugins: [

packages/socket.io-client/support/rollup.config.umd.js

@@ -10,25 +10,15 @@ const banner = `/*!
  * Released under the MIT License.
  */`;
 
-module.exports = {
-  input: "./build/esm/browser-entrypoint.js",
-  output: [
-    {
-      file: "./dist/socket.io.js",
-      format: "umd",
-      name: "io",
-      sourcemap: true,
-      banner,
-    },
-    {
-      file: "./dist/socket.io.min.js",
-      format: "umd",
-      name: "io",
-      sourcemap: true,
-      plugins: [terser()],
-      banner,
-    },
-  ],
+const devBundle = {
+  input: "./build/esm-debug/browser-entrypoint.js",
+  output: {
+    file: "./dist/socket.io.js",
+    format: "umd",
+    name: "io",
+    sourcemap: true,
+    banner,
+  },
   plugins: [
     nodeResolve({
       browser: true,
@@ -37,7 +27,55 @@ module.exports = {
     babel({
       babelHelpers: "bundled",
       presets: [["@babel/env"]],
-      plugins: ["@babel/plugin-transform-object-assign"],
+      plugins: [
+        "@babel/plugin-transform-object-assign",
+        [
+          "@babel/plugin-transform-classes",
+          {
+            loose: true,
+          },
+        ],
+      ],
     }),
   ],
 };
+
+const prodBundle = {
+  input: "./build/esm/browser-entrypoint.js",
+  output: {
+    file: "./dist/socket.io.min.js",
+    format: "umd",
+    name: "io",
+    sourcemap: true,
+    plugins: [
+      terser({
+        mangle: {
+          properties: {
+            regex: /^_/,
+          },
+        },
+      }),
+    ],
+    banner,
+  },
+  plugins: [
+    nodeResolve({
+      browser: true,
+    }),
+    babel({
+      babelHelpers: "bundled",
+      presets: [["@babel/env"]],
+      plugins: [
+        "@babel/plugin-transform-object-assign",
+        [
+          "@babel/plugin-transform-classes",
+          {
+            loose: true,
+          },
+        ],
+      ],
+    }),
+  ],
+};
+
+module.exports = [devBundle, prodBundle];

packages/socket.io-client/support/rollup.config.umd.msgpack.js

@@ -1,13 +1,15 @@
-const base = require("./rollup.config.umd.js");
+const base = require("./rollup.config.umd.js")[1];
 const alias = require("@rollup/plugin-alias");
+const commonjs = require("@rollup/plugin-commonjs");
 
 module.exports = {
   ...base,
   output: {
-    ...base.output[1],
+    ...base.output,
     file: "./dist/socket.io.msgpack.min.js",
   },
   plugins: [
+    commonjs(),
     alias({
       entries: [
         {

packages/socket.io-client/test/connection-state-recovery.ts

@@ -1,4 +1,4 @@
-import expect from "expect.js";
+import expect = require("expect.js");
 import { io } from "..";
 import { wrap, BASE_URL, success } from "./support/util";
 
@@ -7,6 +7,7 @@ describe("connection state recovery", () => {
     return wrap((done) => {
       const socket = io(BASE_URL, {
         forceNew: true,
+        reconnectionDelay: 10,
       });
 
       expect(socket.recovered).to.eql(false);

packages/socket.io-client/test/connection.ts

@@ -1,9 +1,10 @@
-import expect from "expect.js";
+import expect = require("expect.js");
 import { io, Manager, ManagerOptions } from "..";
 import hasCORS from "has-cors";
 import { install } from "@sinonjs/fake-timers";
 import textBlobBuilder from "text-blob-builder";
 import { BASE_URL, wrap } from "./support/util";
+import { nextTick } from "engine.io-client";
 
 describe("connection", () => {
   it("should connect to localhost", () => {
@@ -158,7 +159,7 @@ describe("connection", () => {
 
   it("should reconnect by default", () => {
     return wrap((done) => {
-      const socket = io(BASE_URL, { forceNew: true, reconnectionDelay: 0 });
+      const socket = io(BASE_URL, { forceNew: true, reconnectionDelay: 10 });
       socket.io.on("reconnect", () => {
         socket.disconnect();
         done();
@@ -166,7 +167,7 @@ describe("connection", () => {
 
       setTimeout(() => {
         socket.io.engine.close();
-      }, 500);
+      }, 100);
     });
   });
 
@@ -189,7 +190,7 @@ describe("connection", () => {
 
   it("should reconnect automatically after reconnecting manually", () => {
     return wrap((done) => {
-      const socket = io(BASE_URL, { forceNew: true });
+      const socket = io(BASE_URL, { forceNew: true, reconnectionDelay: 10 });
       socket
         .once("connect", () => {
           socket.disconnect();
@@ -202,7 +203,7 @@ describe("connection", () => {
           socket.connect();
           setTimeout(() => {
             socket.io.engine.close();
-          }, 500);
+          }, 100);
         });
     });
   });
@@ -281,13 +282,13 @@ describe("connection", () => {
       });
       socket.io.once("error", () => {
         socket.io.on("reconnect_attempt", () => {
-          expect().fail();
+          done(new Error("should not happen"));
         });
         socket.disconnect();
         // set a timeout to let reconnection possibly fire
         setTimeout(() => {
           done();
-        }, 500);
+        }, 100);
       });
     });
   });
@@ -301,13 +302,13 @@ describe("connection", () => {
       });
       socket.io.once("reconnect_attempt", () => {
         socket.io.on("reconnect_attempt", () => {
-          expect().fail();
+          done(new Error("should not happen"));
         });
         socket.disconnect();
         // set a timeout to let reconnection possibly fire
         setTimeout(() => {
           done();
-        }, 500);
+        }, 100);
       });
     });
   });
@@ -332,27 +333,29 @@ describe("connection", () => {
 
   it("should stop reconnecting on a socket and keep to reconnect on another", () => {
     return wrap((done) => {
-      const manager = new Manager(BASE_URL);
+      const manager = new Manager(BASE_URL, {
+        reconnectionDelay: 10,
+      });
       const socket1 = manager.socket("/");
       const socket2 = manager.socket("/asd");
 
       manager.on("reconnect_attempt", () => {
         socket1.on("connect", () => {
-          expect().fail();
+          done(new Error("should not happen"));
         });
         socket2.on("connect", () => {
           setTimeout(() => {
             socket2.disconnect();
             manager._close();
             done();
-          }, 500);
+          }, 50);
         });
         socket1.disconnect();
       });
 
       setTimeout(() => {
         manager.engine.close();
-      }, 1000);
+      }, 100);
     });
   });
 
@@ -441,20 +444,19 @@ describe("connection", () => {
         reconnection: true,
         reconnectionDelay: 10,
       });
-      const cb = () => {
-        socket.close();
-        expect().fail();
-      };
-      manager.on("reconnect_attempt", cb);
 
-      var socket = manager.socket("/valid");
+      manager.on("reconnect_attempt", () => {
+        done(new Error("should not happen"));
+      });
+
+      const socket = manager.socket("/valid");
       socket.on("connect", () => {
         // set a timeout to let reconnection possibly fire
         setTimeout(() => {
           socket.close();
           manager._close();
           done();
-        }, 1000);
+        }, 100);
       });
     });
   });
@@ -518,6 +520,28 @@ describe("connection", () => {
     });
   });
 
+  it("should stop trying to reconnect", () => {
+    return wrap((done) => {
+      const manager = new Manager("http://localhost:9823", {
+        reconnectionDelay: 10,
+      });
+
+      manager.on("reconnect_error", () => {
+        // disable current reconnection loop
+        manager.reconnection(false);
+
+        manager.on("reconnect_attempt", () => {
+          done(new Error("should not happen"));
+        });
+
+        setTimeout(() => {
+          manager._close();
+          done();
+        }, 100);
+      });
+    });
+  });
+
   // Ignore incorrect connection test for old IE due to no support for
   // `script.onerror` (see: http://requirejs.org/docs/api.html#ieloadfail)
   if (!global.document || hasCORS) {
@@ -549,12 +573,12 @@ describe("connection", () => {
       return wrap((done) => {
         const manager = new Manager("http://localhost:9823", {
           reconnection: false,
+          reconnectionDelay: 10,
+        });
+
+        manager.on("reconnect_attempt", () => {
+          done(new Error("should not happen"));
         });
-        const cb = () => {
-          socket.close();
-          expect().fail();
-        };
-        manager.on("reconnect_attempt", cb);
 
         manager.on("error", () => {
           // set a timeout to let reconnection possibly fire
@@ -562,7 +586,7 @@ describe("connection", () => {
             socket.disconnect();
             manager._close();
             done();
-          }, 1000);
+          }, 100);
         });
 
         var socket = manager.socket("/invalid");
@@ -574,9 +598,10 @@ describe("connection", () => {
         const manager = new Manager("http://localhost:9823", {
           reconnection: true,
           reconnectionAttempts: 2,
+          reconnectionDelay: 10,
         });
         let delay = Math.floor(
-          manager.reconnectionDelay() * manager.randomizationFactor() * 0.5
+          manager.reconnectionDelay() * manager.randomizationFactor() * 0.5,
         );
         delay = Math.max(delay, 10);
 
@@ -894,4 +919,30 @@ describe("connection", () => {
       });
     });
   });
+
+  it("should close the engine upon decoding exception", () => {
+    return wrap((done) => {
+      const manager = new Manager(BASE_URL, {
+        autoConnect: true,
+        reconnectionDelay: 50,
+      });
+
+      let engine = manager.engine;
+
+      manager.on("open", () => {
+        nextTick(() => {
+          // @ts-expect-error emit() is private
+          manager.engine.emit("data", "bad");
+        });
+      });
+
+      manager.on("reconnect", () => {
+        expect(manager.engine === engine).to.be(false);
+        expect(engine.readyState).to.eql("closed");
+
+        manager._close();
+        done();
+      });
+    });
+  });
 });

packages/socket.io-client/test/fixtures/no-unref.ts

@@ -5,4 +5,4 @@ const socket = io("http://localhost:3211", {
 
 setTimeout(() => {
   console.log("process should not exit");
-}, 500);
+}, 50);

packages/socket.io-client/test/fixtures/unref-during-reconnection.ts

@@ -9,4 +9,4 @@ socket.on("open", () => {
 
 setTimeout(() => {
   console.log("process should exit now");
-}, 500);
+}, 50);