chore(release): 4.7.1

Diff: https://github.com/socketio/socket.io/compare/4.7.0...4.7.1

.github/ISSUE_TEMPLATE/bug_report.md

@@ -2,7 +2,7 @@
 name: Bug report
 about: Create a report to help us improve
 title: ''
-labels: 'bug'
+labels: 'to triage'
 assignees: ''
 
 ---

.github/workflows/ci.yml

@@ -6,21 +6,33 @@ on:
   schedule:
     - cron: '0 0 * * 0'
 
+permissions:
+  contents: read
+
 jobs:
   test-node:
     runs-on: ubuntu-latest
+    timeout-minutes: 10
 
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x, 15.x]
+        node-version:
+          - 16
+          - 20
 
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
-      - run: npm ci
-      - run: npm test
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm test
         env:
           CI: true

CHANGELOG.md

@@ -1,3 +1,665 @@
+# History
+
+## 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/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](#432-2021-11-08) (Nov 2021)
+- [4.3.1](#431-2021-10-16) (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)
+- [**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)
+- [2.4.1](#241-2021-01-07) (Jan 2021) (from the [2.x](https://github.com/socketio/socket.io/tree/2.x) branch)
+- [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/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)
+
+## 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)
+
+
+# Release notes
+
+## [4.7.1](https://github.com/socketio/socket.io/compare/4.7.0...4.7.1) (2023-06-28)
+
+The client bundle contains a few fixes regarding the WebTransport support.
+
+### Dependencies
+
+- [`engine.io@~6.5.0`](https://github.com/socketio/engine.io/releases/tag/6.5.0) (no change)
+- [`ws@~8.11.0`](https://github.com/websockets/ws/releases/tag/8.11.0) (no change)
+
+
+
+## [4.7.0](https://github.com/socketio/socket.io/compare/4.6.2...4.7.0) (2023-06-22)
+
+
+### Bug Fixes
+
+* remove the Partial modifier from the socket.data type ([#4740](https://github.com/socketio/socket.io/issues/4740)) ([e5c62ca](https://github.com/socketio/socket.io/commit/e5c62cad60fc7d16fbb024fd9be1d1880f4e6f5f))
+
+
+### Features
+
+#### Support for WebTransport
+
+The Socket.IO server can now use WebTransport as the underlying transport.
+
+WebTransport is a web API that uses the HTTP/3 protocol as a bidirectional transport. It's intended for two-way communications between a web client and an HTTP/3 server.
+
+References:
+
+- https://w3c.github.io/webtransport/
+- https://developer.mozilla.org/en-US/docs/Web/API/WebTransport
+- https://developer.chrome.com/articles/webtransport/
+
+Until WebTransport support lands [in Node.js](https://github.com/nodejs/node/issues/38478), you can use the `@fails-components/webtransport` package:
+
+```js
+import { readFileSync } from "fs";
+import { createServer } from "https";
+import { Server } from "socket.io";
+import { Http3Server } from "@fails-components/webtransport";
+
+// WARNING: the total length of the validity period MUST NOT exceed two weeks (https://w3c.github.io/webtransport/#custom-certificate-requirements)
+const cert = readFileSync("/path/to/my/cert.pem");
+const key = readFileSync("/path/to/my/key.pem");
+
+const httpsServer = createServer({
+  key,
+  cert
+});
+
+httpsServer.listen(3000);
+
+const io = new Server(httpsServer, {
+  transports: ["polling", "websocket", "webtransport"] // WebTransport is not enabled by default
+});
+
+const h3Server = new Http3Server({
+  port: 3000,
+  host: "0.0.0.0",
+  secret: "changeit",
+  cert,
+  privKey: key,
+});
+
+(async () => {
+  const stream = await h3Server.sessionStream("/socket.io/");
+  const sessionReader = stream.getReader();
+
+  while (true) {
+    const { done, value } = await sessionReader.read();
+    if (done) {
+      break;
+    }
+    io.engine.onWebTransportSession(value);
+  }
+})();
+
+h3Server.startServer();
+```
+
+Added in [123b68c](https://github.com/socketio/engine.io/commit/123b68c04f9e971f59b526e0f967a488ee6b0116).
+
+
+#### Client bundles with CORS headers
+
+The bundles will now have the right `Access-Control-Allow-xxx` headers.
+
+Added in [63f181c](https://github.com/socketio/socket.io/commit/63f181cc12cbbbf94ed40eef52d60f36a1214fbe).
+
+
+### Dependencies
+
+- [`engine.io@~6.5.0`](https://github.com/socketio/engine.io/releases/tag/6.5.0) ([diff](https://github.com/socketio/engine.io/compare/6.4.2...6.5.0))
+- [`ws@~8.11.0`](https://github.com/websockets/ws/releases/tag/8.11.0) (no change)
+
+
+
+## [4.6.2](https://github.com/socketio/socket.io/compare/4.6.1...4.6.2) (2023-05-31)
+
+
+### Bug Fixes
+
+* **exports:** move `types` condition to the top ([#4698](https://github.com/socketio/socket.io/issues/4698)) ([3d44aae](https://github.com/socketio/socket.io/commit/3d44aae381af38349fdb808d510d9f47a0c2507e))
+
+
+### Dependencies
+
+- [`engine.io@~6.4.2`](https://github.com/socketio/engine.io/releases/tag/6.4.0) ([diff](https://github.com/socketio/engine.io/compare/6.4.1...6.4.2))
+- [`ws@~8.11.0`](https://github.com/websockets/ws/releases/tag/8.11.0) (no change)
+
+
+
+## [4.6.1](https://github.com/socketio/socket.io/compare/4.6.0...4.6.1) (2023-02-20)
+
+
+### Bug Fixes
+
+* properly handle manually created dynamic namespaces ([0d0a7a2](https://github.com/socketio/socket.io/commit/0d0a7a22b5ff95f864216c529114b7dd41738d1e))
+* **types:** fix nodenext module resolution compatibility ([#4625](https://github.com/socketio/socket.io/issues/4625)) ([d0b22c6](https://github.com/socketio/socket.io/commit/d0b22c630208669aceb7ae013180c99ef90279b0))
+
+
+### Dependencies
+
+- [`engine.io@~6.4.1`](https://github.com/socketio/engine.io/releases/tag/6.4.1) ([diff](https://github.com/socketio/engine.io/compare/6.4.0...6.4.1))
+- [`ws@~8.11.0`](https://github.com/websockets/ws/releases/tag/8.11.0) (no change)
+
+
+
+## [4.6.0](https://github.com/socketio/socket.io/compare/4.5.4...4.6.0) (2023-02-07)
+
+
+### Bug Fixes
+
+* add timeout method to remote socket ([#4558](https://github.com/socketio/socket.io/issues/4558)) ([0c0eb00](https://github.com/socketio/socket.io/commit/0c0eb0016317218c2be3641e706cfaa9bea39a2d))
+* **typings:** properly type emits with timeout ([f3ada7d](https://github.com/socketio/socket.io/commit/f3ada7d8ccc02eeced2b9b9ac8e4bc921eb630d2))
+
+
+### Features
+
+#### Promise-based acknowledgements
+
+This commit adds some syntactic sugar around acknowledgements:
+
+- `emitWithAck()`
+
+```js
+try {
+  const responses = await io.timeout(1000).emitWithAck("some-event");
+  console.log(responses); // one response per client
+} catch (e) {
+  // some clients did not acknowledge the event in the given delay
+}
+
+io.on("connection", async (socket) => {
+    // without timeout
+  const response = await socket.emitWithAck("hello", "world");
+
+  // with a specific timeout
+  try {
+    const response = await socket.timeout(1000).emitWithAck("hello", "world");
+  } catch (err) {
+    // the client did not acknowledge the event in the given delay
+  }
+});
+```
+
+- `serverSideEmitWithAck()`
+
+```js
+try {
+  const responses = await io.timeout(1000).serverSideEmitWithAck("some-event");
+  console.log(responses); // one response per server (except itself)
+} catch (e) {
+  // some servers did not acknowledge the event in the given delay
+}
+```
+
+Added in [184f3cf](https://github.com/socketio/socket.io/commit/184f3cf7af57acc4b0948eee307f25f8536eb6c8).
+
+#### Connection state recovery
+
+This feature allows a client to reconnect after a temporary disconnection and restore its state:
+
+- id
+- rooms
+- data
+- missed packets
+
+Usage:
+
+```js
+import { Server } from "socket.io";
+
+const io = new Server({
+  connectionStateRecovery: {
+    // default values
+    maxDisconnectionDuration: 2 * 60 * 1000,
+    skipMiddlewares: true,
+  },
+});
+
+io.on("connection", (socket) => {
+  console.log(socket.recovered); // whether the state was recovered or not
+});
+```
+
+Here's how it works:
+
+- the server sends a session ID during the handshake (which is different from the current `id` attribute, which is public and can be freely shared)
+- the server also includes an offset in each packet (added at the end of the data array, for backward compatibility)
+- upon temporary disconnection, the server stores the client state for a given delay (implemented at the adapter level)
+- upon reconnection, the client sends both the session ID and the last offset it has processed, and the server tries to restore the state
+
+The in-memory adapter already supports this feature, and we will soon update the Postgres and MongoDB adapters. We will also create a new adapter based on [Redis Streams](https://redis.io/docs/data-types/streams/), which will support this feature.
+
+Added in [54d5ee0](https://github.com/socketio/socket.io/commit/54d5ee05a684371191e207b8089f09fc24eb5107).
+
+#### Compatibility (for real) with Express middlewares
+
+This feature implements middlewares at the Engine.IO level, because Socket.IO middlewares are meant for namespace authorization and are not executed during a classic HTTP request/response cycle.
+
+Syntax:
+
+```js
+io.engine.use((req, res, next) => {
+  // do something
+
+  next();
+});
+
+// with express-session
+import session from "express-session";
+
+io.engine.use(session({
+  secret: "keyboard cat",
+  resave: false,
+  saveUninitialized: true,
+  cookie: { secure: true }
+}));
+
+// with helmet
+import helmet from "helmet";
+
+io.engine.use(helmet());
+```
+
+A workaround was possible by using the allowRequest option and the "headers" event, but this feels way cleaner and works with upgrade requests too.
+
+Added in [24786e7](https://github.com/socketio/engine.io/commit/24786e77c5403b1c4b5a2bc84e2af06f9187f74a).
+
+#### Error details in the disconnecting and disconnect events
+
+The `disconnect` event will now contain additional details about the disconnection reason.
+
+```js
+io.on("connection", (socket) => {
+  socket.on("disconnect", (reason, description) => {
+    console.log(description);
+  });
+});
+```
+
+Added in [8aa9499](https://github.com/socketio/socket.io/commit/8aa94991cee5518567d6254eec04b23f81510257).
+
+#### Automatic removal of empty child namespaces
+
+This commit adds a new option, "cleanupEmptyChildNamespaces". With this option enabled (disabled by default), when a socket disconnects from a dynamic namespace and if there are no other sockets connected to it then the namespace will be cleaned up and its adapter will be closed. 
+
+```js
+import { createServer } from "node:http";
+import { Server } from "socket.io";
+
+const httpServer = createServer();
+const io = new Server(httpServer, {
+  cleanupEmptyChildNamespaces: true
+});
+```
+
+Added in [5d9220b](https://github.com/socketio/socket.io/commit/5d9220b69adf73e086c27bbb63a4976b348f7c4c).
+
+#### A new "addTrailingSlash" option
+
+The trailing slash which was added by default can now be disabled:
+
+```js
+import { createServer } from "node:http";
+import { Server } from "socket.io";
+
+const httpServer = createServer();
+const io = new Server(httpServer, {
+  addTrailingSlash: false
+});
+```
+
+In the example above, the clients can omit the trailing slash and use `/socket.io` instead of `/socket.io/`.
+
+Added in [d0fd474](https://github.com/socketio/engine.io/commit/d0fd4746afa396297f07bb62e539b0c1c4018d7c).
+
+### Performance Improvements
+
+* precompute the WebSocket frames when broadcasting ([da2b542](https://github.com/socketio/socket.io/commit/da2b54279749adc5279c9ac4742b01b36c01cff0))
+
+
+### Dependencies
+
+- [`engine.io@~6.4.0`](https://github.com/socketio/engine.io/releases/tag/6.4.0) (https://github.com/socketio/engine.io/compare/6.2.1...6.4.0)
+- [`ws@~8.11.0`](https://github.com/websockets/ws/releases/tag/8.11.0) (https://github.com/websockets/ws/compare/8.2.3...8.11.0)
+
+
+## [4.5.4](https://github.com/socketio/socket.io/compare/4.5.3...4.5.4) (2022-11-22)
+
+This release contains a bump of:
+
+- `engine.io` in order to fix [CVE-2022-41940](https://github.com/socketio/engine.io/security/advisories/GHSA-r7qp-cfhv-p84w)
+- `socket.io-parser` in order to fix [CVE-2022-2421](https://github.com/advisories/GHSA-qm95-pgcg-qqfq).
+
+### Dependencies
+
+- [`engine.io@~6.2.1`](https://github.com/socketio/engine.io/releases/tag/6.2.1) ([diff](https://github.com/socketio/engine.io/compare/6.2.0...6.2.1))
+- [`ws@~8.2.3`](https://github.com/websockets/ws/releases/tag/8.2.3) (no change)
+
+
+
+## [4.5.3](https://github.com/socketio/socket.io/compare/4.5.2...4.5.3) (2022-10-15)
+
+
+### Bug Fixes
+
+* **typings:** accept an HTTP2 server in the constructor ([d3d0a2d](https://github.com/socketio/socket.io/commit/d3d0a2d5beaff51fd145f810bcaf6914213f8a06))
+* **typings:** apply types to "io.timeout(...).emit()" calls ([e357daf](https://github.com/socketio/socket.io/commit/e357daf5858560bc84e7e50cd36f0278d6721ea1))
+
+### Dependencies
+
+- [`engine.io@~6.2.0`](https://github.com/socketio/engine.io/releases/tag/6.2.1) (no change)
+- [`ws@~8.2.3`](https://github.com/websockets/ws/releases/tag/8.2.3) (no change)
+
+
+
+## [4.5.2](https://github.com/socketio/socket.io/compare/4.5.1...4.5.2) (2022-09-02)
+
+
+### Bug Fixes
+
+* prevent the socket from joining a room after disconnection ([18f3fda](https://github.com/socketio/socket.io/commit/18f3fdab12947a9fee3e9c37cfc1da97027d1473))
+* **uws:** prevent the server from crashing after upgrade ([ba497ee](https://github.com/socketio/socket.io/commit/ba497ee3eb52c4abf1464380d015d8c788714364))
+
+### Dependencies
+
+- [`engine.io@~6.2.0`](https://github.com/socketio/engine.io/releases/tag/6.2.0) (no change)
+- [`ws@~8.2.3`](https://github.com/websockets/ws/releases/tag/8.2.3) (no change)
+
+
+
+# [2.5.0](https://github.com/socketio/socket.io/compare/2.4.1...2.5.0) (2022-06-26)
+
+⚠️ WARNING ⚠️
+
+The default value of the `maxHttpBufferSize` option has been decreased from 100 MB to 1 MB, in order to prevent attacks by denial of service.
+
+Security advisory: [GHSA-j4f2-536g-r55m](https://github.com/advisories/GHSA-j4f2-536g-r55m)
+
+
+### Bug Fixes
+
+* fix race condition in dynamic namespaces ([05e1278](https://github.com/socketio/socket.io/commit/05e1278cfa99f3ecf3f8f0531ffe57d850e9a05b))
+* ignore packet received after disconnection ([22d4bdf](https://github.com/socketio/socket.io/commit/22d4bdf00d1a03885dc0171125faddfaef730066))
+* only set 'connected' to true after middleware execution ([226cc16](https://github.com/socketio/socket.io/commit/226cc16165f9fe60f16ff4d295fb91c8971cde35))
+* prevent the socket from joining a room after disconnection ([f223178](https://github.com/socketio/socket.io/commit/f223178eb655a7713303b21a78f9ef9e161d6458))
+
+### Dependencies
+
+- [`engine.io@~3.6.0`](https://github.com/socketio/engine.io/releases/tag/3.6.0) (https://github.com/socketio/engine.io/compare/3.5.0...3.6.0)
+- [`ws@~7.4.2`](https://github.com/websockets/ws/releases/tag/7.4.2) (no change)
+
+
+
+## [4.5.1](https://github.com/socketio/socket.io/compare/4.5.0...4.5.1) (2022-05-17)
+
+
+### Bug Fixes
+
+* forward the local flag to the adapter when using fetchSockets() ([30430f0](https://github.com/socketio/socket.io/commit/30430f0985f8e7c49394543d4c84913b6a15df60))
+* **typings:** add HTTPS server to accepted types ([#4351](https://github.com/socketio/socket.io/issues/4351)) ([9b43c91](https://github.com/socketio/socket.io/commit/9b43c9167cff817c60fa29dbda2ef7cd938aff51))
+
+### Dependencies
+
+- [`engine.io@~6.2.0`](https://github.com/socketio/engine.io/releases/tag/6.2.0) (no change)
+- [`ws@~8.2.3`](https://github.com/websockets/ws/releases/tag/8.2.3) (no change)
+
+
+
+# [4.5.0](https://github.com/socketio/socket.io/compare/4.4.1...4.5.0) (2022-04-23)
+
+
+### Bug Fixes
+
+* **typings:** ensure compatibility with TypeScript 3.x ([#4259](https://github.com/socketio/socket.io/issues/4259)) ([02c87a8](https://github.com/socketio/socket.io/commit/02c87a85614e217b8e7b93753f315790ae9d99f6))
+
+
+### Features
+
+#### Catch-all listeners for outgoing packets
+
+This is similar to `onAny()`, but for outgoing packets.
+
+Syntax:
+
+```js
+socket.onAnyOutgoing((event, ...args) => {
+  console.log(event);
+});
+```
+
+Added in [531104d](https://github.com/socketio/socket.io/commit/531104d332690138b7aab84d5583d6204132c8b4).
+
+#### Broadcast and expect multiple acknowledgements
+
+Syntax:
+
+```js
+io.timeout(1000).emit("some-event", (err, responses) => {
+  // ...
+});
+```
+
+Added in [8b20457](https://github.com/socketio/socket.io/commit/8b204570a94979bbec307f23ca078f30f5cf07b0).
+
+#### `maxHttpBufferSize` value negotiation
+
+A "maxPayload" field is now included in the Engine.IO handshake, so that clients in HTTP long-polling can decide how many packets they have to send to stay under the `maxHttpBufferSize` value.
+
+This is a backward compatible change which should not mandate a new major revision of the protocol (we stay in v4), as we only add a field in the JSON-encoded handshake data:
+
+```
+0{"sid":"lv_VI97HAXpY6yYWAAAC","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":5000,"maxPayload":1000000}
+```
+
+Added in [088dcb4](https://github.com/socketio/engine.io/commit/088dcb4dff60df39785df13d0a33d3ceaa1dff38).
+
+### Dependencies
+
+- [`engine.io@~6.2.0`](https://github.com/socketio/engine.io/releases/tag/6.2.0) (https://github.com/socketio/engine.io/compare/6.1.0...6.2.0)
+- [`ws@~8.2.3`](https://github.com/websockets/ws/releases/tag/8.2.3) (no change)
+
+
+
+## [4.4.1](https://github.com/socketio/socket.io/compare/4.4.0...4.4.1) (2022-01-06)
+
+
+### Bug Fixes
+
+* **types:** make `RemoteSocket.data` type safe ([#4234](https://github.com/socketio/socket.io/issues/4234)) ([770ee59](https://github.com/socketio/socket.io/commit/770ee5949fb47c2556876c622f06c862573657d6))
+* **types:** pass `SocketData` type to custom namespaces ([#4233](https://github.com/socketio/socket.io/issues/4233)) ([f2b8de7](https://github.com/socketio/socket.io/commit/f2b8de71919e1b4d3e57f15a459972c1d1064787))
+
+
+
+# [4.4.0](https://github.com/socketio/socket.io/compare/4.3.2...4.4.0) (2021-11-18)
+
+
+### Bug Fixes
+
+* only set 'connected' to true after middleware execution ([02b0f73](https://github.com/socketio/socket.io/commit/02b0f73e2c64b09c72c5fbf7dc5f059557bdbe50))
+
+
+### Features
+
+* add an implementation based on uWebSockets.js ([c0d8c5a](https://github.com/socketio/socket.io/commit/c0d8c5ab234d0d2bef0d0dec472973cc9662f647))
+* add timeout feature ([f0ed42f](https://github.com/socketio/socket.io/commit/f0ed42f18cabef20ad976aeec37077b6bf3837a5))
+* add type information to `socket.data` ([#4159](https://github.com/socketio/socket.io/issues/4159)) ([fe8730c](https://github.com/socketio/socket.io/commit/fe8730ca0f15bc92d5de81cf934c89c76d6af329))
+
+
+
+## [4.3.2](https://github.com/socketio/socket.io/compare/4.3.1...4.3.2) (2021-11-08)
+
+
+### Bug Fixes
+
+* fix race condition in dynamic namespaces ([#4137](https://github.com/socketio/socket.io/issues/4137)) ([9d86397](https://github.com/socketio/socket.io/commit/9d86397243bcbb5775a29d96e5ef03e17148a8e7))
+
+
+## [4.3.1](https://github.com/socketio/socket.io/compare/4.3.0...4.3.1) (2021-10-16)
+
+
+### Bug Fixes
+
+* fix server attachment ([#4127](https://github.com/socketio/socket.io/issues/4127)) ([0ef2a4d](https://github.com/socketio/socket.io/commit/0ef2a4d02c9350aff163df9cb61aece89c4dac0f))
+
+
+# [4.3.0](https://github.com/socketio/socket.io/compare/4.2.0...4.3.0) (2021-10-14)
+
+
+### Bug Fixes
+
+* **typings:** add name field to cookie option ([#4099](https://github.com/socketio/socket.io/issues/4099)) ([033c5d3](https://github.com/socketio/socket.io/commit/033c5d399a2b985afad32c1e4b0c16d764e248cd))
+* send volatile packets with binary attachments ([dc81fcf](https://github.com/socketio/socket.io/commit/dc81fcf461cfdbb5b34b1a5a96b84373754047d5))
+
+
+### Features
+
+* serve ESM bundle ([60edecb](https://github.com/socketio/socket.io/commit/60edecb3bd33801803cdcba0aefbafa381a2abb3))
+
+
+# [4.2.0](https://github.com/socketio/socket.io/compare/4.1.3...4.2.0) (2021-08-30)
+
+
+### Bug Fixes
+
+* **typings:** allow async listener in typed events ([ccfd8ca](https://github.com/socketio/socket.io/commit/ccfd8caba6d38b7ba6c5114bd8179346ed07671c))
+
+
+### Features
+
+* ignore the query string when serving client JavaScript ([#4024](https://github.com/socketio/socket.io/issues/4024)) ([24fee27](https://github.com/socketio/socket.io/commit/24fee27ba36485308f8e995879c10931532c814e))
+
+
+## [4.1.3](https://github.com/socketio/socket.io/compare/4.1.2...4.1.3) (2021-07-10)
+
+
+### Bug Fixes
+
+* fix io.except() method ([94e27cd](https://github.com/socketio/socket.io/commit/94e27cd072c8a4eeb9636f6ffbb7a21d382f36b0))
+* remove x-sourcemap header ([a4dffc6](https://github.com/socketio/socket.io/commit/a4dffc6527f412d51a786ae5bf2e9080fe1ca63c))
+
+
+## [4.1.2](https://github.com/socketio/socket.io/compare/4.1.1...4.1.2) (2021-05-17)
+
+
+### Bug Fixes
+
+* **typings:** ensure compatibility with TypeScript 3.x ([0cb6ac9](https://github.com/socketio/socket.io/commit/0cb6ac95b49a27483b6f1b6402fa54b35f82e36f))
+* ensure compatibility with previous versions of the adapter ([a2cf248](https://github.com/socketio/socket.io/commit/a2cf2486c366cb62293101c10520c57f6984a3fc))
+
+
+## [4.1.1](https://github.com/socketio/socket.io/compare/4.1.0...4.1.1) (2021-05-11)
+
+
+### Bug Fixes
+
+* **typings:** properly type server-side events ([b84ed1e](https://github.com/socketio/socket.io/commit/b84ed1e41c9053792caf58974c5de9395bfd509f))
+* **typings:** properly type the adapter attribute ([891b187](https://github.com/socketio/socket.io/commit/891b1870e92d1ec38910f03bb839817e2d6be65a))
+
+
+# [4.1.0](https://github.com/socketio/socket.io/compare/4.0.2...4.1.0) (2021-05-11)
+
+
+### Features
+
+* add support for inter-server communication ([93cce05](https://github.com/socketio/socket.io/commit/93cce05fb3faf91f21fa71212275c776aa161107))
+* notify upon namespace creation ([499c892](https://github.com/socketio/socket.io/commit/499c89250d2db1ab7725ab2b74840e188c267c46))
+* add a "connection_error" event ([7096e98](https://github.com/socketio/engine.io/commit/7096e98a02295a62c8ea2aa56461d4875887092d), from `engine.io`)
+* add the "initial_headers" and "headers" events ([2527543](https://github.com/socketio/engine.io/commit/252754353a0e88eb036ebb3082e9d6a9a5f497db), from `engine.io`)
+
+
+### Performance Improvements
+
+* add support for the "wsPreEncoded" writing option ([dc381b7](https://github.com/socketio/socket.io/commit/dc381b72c6b2f8172001dedd84116122e4cc95b3))
+
+
+## [4.0.2](https://github.com/socketio/socket.io/compare/4.0.1...4.0.2) (2021-05-06)
+
+
+### Bug Fixes
+
+* **typings:** make "engine" attribute public ([b81ce4c](https://github.com/socketio/socket.io/commit/b81ce4c9d0b00666361498e2ba5e0d007d5860b8))
+* properly export the Socket class ([d65b6ee](https://github.com/socketio/socket.io/commit/d65b6ee84c8e91deb61c3c1385eb19afa196a909))
+
+
+## [4.0.1](https://github.com/socketio/socket.io/compare/4.0.0...4.0.1) (2021-03-31)
+
+
+### Bug Fixes
+
+* **typings:** add fallback to untyped event listener ([#3834](https://github.com/socketio/socket.io/issues/3834)) ([a11152f](https://github.com/socketio/socket.io/commit/a11152f42b281df83409313962f60f230239c79e))
+* **typings:** update return type from emit ([#3843](https://github.com/socketio/socket.io/issues/3843)) ([1a72ae4](https://github.com/socketio/socket.io/commit/1a72ae4fe27a14cf60916f991a2c94da91d9e54a))
+
+
+# [4.0.0](https://github.com/socketio/socket.io/compare/3.1.2...4.0.0) (2021-03-10)
+
+
+### Bug Fixes
+
+* make io.to(...) immutable ([ac9e8ca](https://github.com/socketio/socket.io/commit/ac9e8ca6c71e00d4af45ee03f590fe56f3951186))
+
+
+### Features
+
+* add some utility methods ([b25495c](https://github.com/socketio/socket.io/commit/b25495c069031674da08e19aed68922c7c7a0e28))
+* add support for typed events ([#3822](https://github.com/socketio/socket.io/issues/3822)) ([0107510](https://github.com/socketio/socket.io/commit/0107510ba8a0f148c78029d8be8919b350feb633))
+* allow to exclude specific rooms when broadcasting ([#3789](https://github.com/socketio/socket.io/issues/3789)) ([7de2e87](https://github.com/socketio/socket.io/commit/7de2e87e888d849eb2dfc5e362af4c9e86044701))
+* allow to pass an array to io.to(...) ([085d1de](https://github.com/socketio/socket.io/commit/085d1de9df909651de8b313cc6f9f253374b702e))
+
+
+## [3.1.2](https://github.com/socketio/socket.io/compare/3.1.1...3.1.2) (2021-02-26)
+
+
+### Bug Fixes
+
+* ignore packets received after disconnection ([494c64e](https://github.com/socketio/socket.io/commit/494c64e44f645cbd24c645f1186d203789e84af0))
+
+
 ## [3.1.1](https://github.com/socketio/socket.io/compare/3.1.0...3.1.1) (2021-02-03)
 
 
@@ -24,6 +686,16 @@
 * allow integers as event names ([1c220dd](https://github.com/socketio/socket.io-parser/commit/1c220ddbf45ea4b44bc8dbf6f9ae245f672ba1b9))
 
 
+
+## [2.4.1](https://github.com/socketio/socket.io/compare/2.4.0...2.4.1) (2021-01-07)
+
+
+### Reverts
+
+* fix(security): do not allow all origins by default ([a169050](https://github.com/socketio/socket.io/commit/a1690509470e9dd5559cec4e60908ca6c23e9ba0))
+
+
+
 ## [3.0.5](https://github.com/socketio/socket.io/compare/3.0.4...3.0.5) (2021-01-05)
 
 
@@ -37,6 +709,17 @@
 * restore the socket middleware functionality ([bf54327](https://github.com/socketio/socket.io/commit/bf5432742158e4d5ba2722cff4a614967dffa5b9))
 
 
+
+# [2.4.0](https://github.com/socketio/socket.io/compare/2.3.0...2.4.0) (2021-01-04)
+
+
+### Bug Fixes
+
+* **security:** do not allow all origins by default ([f78a575](https://github.com/socketio/socket.io/commit/f78a575f66ab693c3ea96ea88429ddb1a44c86c7))
+* properly overwrite the query sent in the handshake ([d33a619](https://github.com/socketio/socket.io/commit/d33a619905a4905c153d4fec337c74da5b533a9e))
+
+
+
 ## [3.0.4](https://github.com/socketio/socket.io/compare/3.0.3...3.0.4) (2020-12-07)
 
 
@@ -322,3 +1005,78 @@ io.of("/admin").use((socket, next) => {
 
 This method was kept for backward-compatibility with pre-1.0 versions.
 
+
+
+# [2.3.0](https://github.com/socketio/socket.io/compare/2.2.0...2.3.0) (2019-09-20)
+
+This release mainly contains a bump of the `engine.io` and `ws` packages, but no additional features.
+
+
+
+# [2.2.0](https://github.com/socketio/socket.io/compare/2.1.1...2.2.0) (2018-11-29)
+
+### Features
+
+- add cache-control header when serving the client source ([#2907](https://github.com/socketio/socket.io/pull/2907)) ([b00ae50](https://github.com/socketio/socket.io/commit/b00ae50be65d1bc88fa95145f1c486a6886a6b76))
+
+### Bug fixes
+
+- throw an error when trying to access the clients of a dynamic namespace ([#3355](https://github.com/socketio/socket.io/pull/3355)) ([a7fbd1a](https://github.com/socketio/socket.io/commit/a7fbd1ac4a47cafd832fc62e371754df924c5903))
+
+
+
+# [2.1.1](https://github.com/socketio/socket.io/compare/2.1.0...2.1.1) (2018-05-17)
+
+### Features
+
+- add local flag to the socket object ([#3129](https://github.com/socketio/socket.io/pull/3219)) ([1decae3](https://github.com/socketio/socket.io/commit/1decae341c80c0417b32d3124ca30c005240b48a))
+
+```js
+socket.local.to('room101').emit(/* */);
+```
+
+
+# [2.1.0](https://github.com/socketio/socket.io/compare/2.1.1...2.2.0) (2018-03-29)
+
+### Features
+
+- add a 'binary' flag ([#3185](https://github.com/socketio/socket.io/pull/3185)) ([f48a06c](https://github.com/socketio/socket.io/commit/f48a06c040280b44f90fd225c888910544fd63b5))
+
+```js
+// by default, the object is recursively scanned to check whether it contains some binary data
+// in the following example, the check is skipped in order to improve performance
+socket.binary(false).emit('plain-object', object);
+
+// it also works at the namespace level
+io.binary(false).emit('plain-object', object);
+```
+
+- add support for dynamic namespaces ([#3195](https://github.com/socketio/socket.io/pull/3195)) ([c0c79f0](https://github.com/socketio/socket.io/commit/c0c79f019e7138194e438339f8192705957c8ec3))
+
+```js
+io.of(/^\/dynamic-\d+$/).on('connect', (socket) => {
+  // socket.nsp.name = '/dynamic-101'
+});
+
+// client-side
+const client = require('socket.io-client')('/dynamic-101');
+```
+
+### Bug fixes
+
+- properly emit 'connect' when using a custom namespace ([#3197](https://github.com/socketio/socket.io/pull/3197)) ([f4fc517](https://github.com/socketio/socket.io/commit/f4fc517e0fe25866c95b584291487b8cbdff889d))
+- include the protocol in the origins check ([#3198](https://github.com/socketio/socket.io/pull/3198)) ([1f1d64b](https://github.com/socketio/socket.io/commit/1f1d64bab61a273712a199591a3f76210d8c0959))
+
+### Important note :warning: from Engine.IO [3.2.0 release](https://github.com/socketio/engine.io/releases/tag/3.2.0)
+
+There are two non-breaking changes that are somehow quite important:
+
+- `ws` was reverted as the default wsEngine (https://github.com/socketio/engine.io/pull/550), as there was several blocking issues with `uws`. You can still use `uws` by running `npm install uws --save` in your project and using the `wsEngine` option:
+```js
+var engine = require('engine.io');
+var server = engine.listen(3000, {
+  wsEngine: 'uws'
+});
+```
+
+- `pingTimeout` now defaults to 5 seconds (instead of 60 seconds): https://github.com/socketio/engine.io/pull/551

Readme.md

@@ -1,9 +1,7 @@
 # socket.io
-[![Run on Repl.it](https://repl.it/badge/github/socketio/socket.io)](https://repl.it/github/socketio/socket.io)
+[![Run on Repl.it](https://repl.it/badge/github/socketio/socket.io)](https://replit.com/@socketio/socketio-minimal-example)
 [![Backers on Open Collective](https://opencollective.com/socketio/backers/badge.svg)](#backers) [![Sponsors on Open Collective](https://opencollective.com/socketio/sponsors/badge.svg)](#sponsors)
 [![Build Status](https://github.com/socketio/socket.io/workflows/CI/badge.svg)](https://github.com/socketio/socket.io/actions)
-[![Dependency Status](https://david-dm.org/socketio/socket.io.svg)](https://david-dm.org/socketio/socket.io)
-[![devDependency Status](https://david-dm.org/socketio/socket.io/dev-status.svg)](https://david-dm.org/socketio/socket.io#info=devDependencies)
 [![NPM version](https://badge.fury.io/js/socket.io.svg)](https://www.npmjs.com/package/socket.io)
 ![Downloads](https://img.shields.io/npm/dm/socket.io.svg?style=flat)
 [![](https://slackin-socketio.now.sh/badge.svg)](https://slackin-socketio.now.sh)
@@ -22,7 +20,8 @@ Some implementations in other languages are also available:
 - [Swift](https://github.com/socketio/socket.io-client-swift)
 - [Dart](https://github.com/rikulo/socket.io-client-dart)
 - [Python](https://github.com/miguelgrinberg/python-socketio)
-- [.Net](https://github.com/Quobject/SocketIoClientDotNet)
+- [.NET](https://github.com/doghappy/socket.io-client-csharp)
+- [Rust](https://github.com/1c3t3a/rust-socketio)
 
 Its main features are:
 
@@ -115,11 +114,19 @@ io.on('connection', client => { ... });
 io.listen(3000);
 ```
 
+### Module syntax 
+
+```js
+import { Server } from "socket.io";
+const io = new Server(server);
+io.listen(3000);
+```
+
 ### In conjunction with Express
 
 Starting with **3.0**, express applications have become request handler
 functions that you pass to `http` or `http` `Server` instances. You need
-to pass the `Server` to `socket.io`, and not the express application
+to pass the `Server` to `socket.io`, not the express application
 function. Also make sure to call `.listen` on the `server`, not the `app`.
 
 ```js

SECURITY.md

@@ -0,0 +1,22 @@
+# Security Policy
+
+## Supported Versions
+
+| Version | Supported          |
+|---------|--------------------|
+| 4.x     | :white_check_mark: |
+| 3.x     | :white_check_mark: |
+| 2.4.x   | :white_check_mark: |
+| < 2.4.0 | :x:                |
+
+## Reporting a Vulnerability
+
+To report a security vulnerability in this package, please send an email to [@darrachequesne](https://github.com/darrachequesne) (see address in profile) describing the vulnerability and how to reproduce it.
+
+We will get back to you as soon as possible and publish a fix if necessary.
+
+:warning: IMPORTANT :warning: please do not create an issue in this repository, as attackers might take advantage of it. Thank you in advance for your responsible disclosure.
+
+## History
+
+No security vulnerability were reported yet.

examples/.gitignore

@@ -0,0 +1 @@
+package-lock.json

examples/angular-todomvc/package.json

@@ -21,8 +21,8 @@
     "@angular/platform-browser-dynamic": "~11.0.4",
     "@angular/router": "~11.0.4",
     "rxjs": "~6.6.0",
-    "socket.io": "^3.0.4",
-    "socket.io-client": "^3.0.4",
+    "socket.io": "^4.0.0",
+    "socket.io-client": "^4.0.0",
     "tslib": "^2.0.0",
     "zone.js": "~0.10.2"
   },

examples/angular-todomvc/server.ts

@@ -1,4 +1,4 @@
-import { Server, Socket } from "socket.io";
+import { Server } from "socket.io";
 
 const io = new Server(8080, {
   cors: {
@@ -15,7 +15,7 @@ interface Todo {
 
 let todos: Array<Todo> = [];
 
-io.on("connect", (socket: Socket) => {
+io.on("connect", (socket) => {
     socket.emit("todos", todos);
 
     // note: we could also create a CRUD (create/read/update/delete) service for the todo list

examples/basic-crud-application/README.md

@@ -0,0 +1,26 @@
+# Basic CRUD application with Socket.IO
+
+Please read the related [guide](https://socket.io/get-started/basic-crud-application/).
+
+This repository contains several implementations of the server:
+
+| Directory                  | Language   | Database                                                                           | Cluster?                                                                                   |
+|----------------------------|------------|------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------|
+| `server/`                  | TypeScript | in-memory                                                                          | No                                                                                         |
+| `server-postgres-cluster/` | JavaScript | Postgres, with the [Postgres adapter](https://socket.io/docs/v4/postgres-adapter/) | Yes, with the [`@socket.io/sticky`](https://github.com/socketio/socket.io-sticky) module)  |
+
+## Running the frontend
+
+```
+cd angular-client
+npm install
+npm start
+```
+
+### Running the server
+
+```
+cd server
+npm install
+npm start
+```

examples/basic-crud-application/angular-client/.browserslistrc

@@ -0,0 +1,17 @@
+# This file is used by the build system to adjust CSS and JS output to support the specified browsers below.
+# For additional information regarding the format and rule options, please see:
+# https://github.com/browserslist/browserslist#queries
+
+# For the full list of supported browsers by the Angular framework, please see:
+# https://angular.io/guide/browser-support
+
+# You can see what browsers were selected by your queries by running:
+#   npx browserslist
+
+last 1 Chrome version
+last 1 Firefox version
+last 2 Edge major versions
+last 2 Safari major versions
+last 2 iOS major versions
+Firefox ESR
+not IE 11 # Angular supports IE 11 only as an opt-in. To opt-in, remove the 'not' prefix on this line.

examples/basic-crud-application/angular-client/.editorconfig

@@ -0,0 +1,16 @@
+# Editor configuration, see https://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.ts]
+quote_type = single
+
+[*.md]
+max_line_length = off
+trim_trailing_whitespace = false

examples/basic-crud-application/angular-client/.gitignore

@@ -0,0 +1,46 @@
+# See http://help.github.com/ignore-files/ for more about ignoring files.
+
+# compiled output
+/dist
+/tmp
+/out-tsc
+# Only exists if Bazel was run
+/bazel-out
+
+# dependencies
+/node_modules
+
+# profiling files
+chrome-profiler-events*.json
+speed-measure-plugin*.json
+
+# 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
+.history/*
+
+# misc
+/.sass-cache
+/connect.lock
+/coverage
+/libpeerconnection.log
+npm-debug.log
+yarn-error.log
+testem.log
+/typings
+
+# System Files
+.DS_Store
+Thumbs.db

examples/basic-crud-application/angular-client/README.md

@@ -0,0 +1,31 @@
+# Angular TodoMVC + Socket.IO
+
+This project was generated with [Angular CLI](https://github.com/angular/angular-cli) version 11.0.4.
+
+Inspired from the [TodoMVC](http://todomvc.com/) [angular example](https://github.com/tastejs/todomvc/tree/master/examples/angular2).
+
+![demo](assets/demo.gif)
+
+## Development server
+
+Run `ng serve` for a dev server. Navigate to `http://localhost:4200/`. The app will automatically reload if you change any of the source files.
+
+## Code scaffolding
+
+Run `ng generate component component-name` to generate a new component. You can also use `ng generate directive|pipe|service|class|guard|interface|enum|module`.
+
+## Build
+
+Run `ng build` to build the project. The build artifacts will be stored in the `dist/` directory. Use the `--prod` flag for a production build.
+
+## Running unit tests
+
+Run `ng test` to execute the unit tests via [Karma](https://karma-runner.github.io).
+
+## Running end-to-end tests
+
+Run `ng e2e` to execute the end-to-end tests via [Protractor](http://www.protractortest.org/).
+
+## Further help
+
+To get more help on the Angular CLI use `ng help` or go check out the [Angular CLI Overview and Command Reference](https://angular.io/cli) page.

examples/basic-crud-application/angular-client/angular.json

@@ -0,0 +1,128 @@
+{
+  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
+  "version": 1,
+  "newProjectRoot": "projects",
+  "projects": {
+    "angular-todomvc": {
+      "projectType": "application",
+      "schematics": {
+        "@schematics/angular:application": {
+          "strict": true
+        }
+      },
+      "root": "",
+      "sourceRoot": "src",
+      "prefix": "app",
+      "architect": {
+        "build": {
+          "builder": "@angular-devkit/build-angular:browser",
+          "options": {
+            "outputPath": "dist/angular-todomvc",
+            "index": "src/index.html",
+            "main": "src/main.ts",
+            "polyfills": "src/polyfills.ts",
+            "tsConfig": "tsconfig.app.json",
+            "aot": true,
+            "assets": [
+              "src/favicon.ico",
+              "src/assets"
+            ],
+            "styles": [
+              "src/styles.css"
+            ],
+            "scripts": []
+          },
+          "configurations": {
+            "production": {
+              "fileReplacements": [
+                {
+                  "replace": "src/environments/environment.ts",
+                  "with": "src/environments/environment.prod.ts"
+                }
+              ],
+              "optimization": true,
+              "outputHashing": "all",
+              "sourceMap": false,
+              "namedChunks": false,
+              "extractLicenses": true,
+              "vendorChunk": false,
+              "buildOptimizer": true,
+              "budgets": [
+                {
+                  "type": "initial",
+                  "maximumWarning": "500kb",
+                  "maximumError": "1mb"
+                },
+                {
+                  "type": "anyComponentStyle",
+                  "maximumWarning": "2kb",
+                  "maximumError": "4kb"
+                }
+              ]
+            }
+          }
+        },
+        "serve": {
+          "builder": "@angular-devkit/build-angular:dev-server",
+          "options": {
+            "browserTarget": "angular-todomvc:build"
+          },
+          "configurations": {
+            "production": {
+              "browserTarget": "angular-todomvc:build:production"
+            }
+          }
+        },
+        "extract-i18n": {
+          "builder": "@angular-devkit/build-angular:extract-i18n",
+          "options": {
+            "browserTarget": "angular-todomvc:build"
+          }
+        },
+        "test": {
+          "builder": "@angular-devkit/build-angular:karma",
+          "options": {
+            "main": "src/test.ts",
+            "polyfills": "src/polyfills.ts",
+            "tsConfig": "tsconfig.spec.json",
+            "karmaConfig": "karma.conf.js",
+            "assets": [
+              "src/favicon.ico",
+              "src/assets"
+            ],
+            "styles": [
+              "src/styles.css"
+            ],
+            "scripts": []
+          }
+        },
+        "lint": {
+          "builder": "@angular-devkit/build-angular:tslint",
+          "options": {
+            "tsConfig": [
+              "tsconfig.app.json",
+              "tsconfig.spec.json",
+              "e2e/tsconfig.json"
+            ],
+            "exclude": [
+              "**/node_modules/**"
+            ]
+          }
+        },
+        "e2e": {
+          "builder": "@angular-devkit/build-angular:protractor",
+          "options": {
+            "protractorConfig": "e2e/protractor.conf.js",
+            "devServerTarget": "angular-todomvc:serve"
+          },
+          "configurations": {
+            "production": {
+              "devServerTarget": "angular-todomvc:serve:production"
+            }
+          }
+        }
+      }
+    }
+  },
+  "defaultProject": "angular-todomvc"
+}

examples/basic-crud-application/angular-client/e2e/protractor.conf.js

@@ -0,0 +1,37 @@
+// @ts-check
+// Protractor configuration file, see link for more information
+// https://github.com/angular/protractor/blob/master/lib/config.ts
+
+const { SpecReporter, StacktraceOption } = require('jasmine-spec-reporter');
+
+/**
+ * @type { import("protractor").Config }
+ */
+exports.config = {
+  allScriptsTimeout: 11000,
+  specs: [
+    './src/**/*.e2e-spec.ts'
+  ],
+  capabilities: {
+    browserName: 'chrome'
+  },
+  directConnect: true,
+  SELENIUM_PROMISE_MANAGER: false,
+  baseUrl: 'http://localhost:4200/',
+  framework: 'jasmine',
+  jasmineNodeOpts: {
+    showColors: true,
+    defaultTimeoutInterval: 30000,
+    print: function() {}
+  },
+  onPrepare() {
+    require('ts-node').register({
+      project: require('path').join(__dirname, './tsconfig.json')
+    });
+    jasmine.getEnv().addReporter(new SpecReporter({
+      spec: {
+        displayStacktrace: StacktraceOption.PRETTY
+      }
+    }));
+  }
+};

examples/basic-crud-application/angular-client/e2e/src/app.e2e-spec.ts

@@ -0,0 +1,23 @@
+import { AppPage } from './app.po';
+import { browser, logging } from 'protractor';
+
+describe('workspace-project App', () => {
+  let page: AppPage;
+
+  beforeEach(() => {
+    page = new AppPage();
+  });
+
+  it('should display welcome message', async () => {
+    await page.navigateTo();
+    expect(await page.getTitleText()).toEqual('angular-todomvc app is running!');
+  });
+
+  afterEach(async () => {
+    // Assert that there are no errors emitted from the browser
+    const logs = await browser.manage().logs().get(logging.Type.BROWSER);
+    expect(logs).not.toContain(jasmine.objectContaining({
+      level: logging.Level.SEVERE,
+    } as logging.Entry));
+  });
+});

examples/basic-crud-application/angular-client/e2e/src/app.po.ts

@@ -0,0 +1,11 @@
+import { browser, by, element } from 'protractor';
+
+export class AppPage {
+  async navigateTo(): Promise<unknown> {
+    return browser.get(browser.baseUrl);
+  }
+
+  async getTitleText(): Promise<string> {
+    return element(by.css('app-root .content span')).getText();
+  }
+}

examples/basic-crud-application/angular-client/e2e/tsconfig.json

@@ -0,0 +1,13 @@
+/* To learn more about this file see: https://angular.io/config/tsconfig. */
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../out-tsc/e2e",
+    "module": "commonjs",
+    "target": "es2018",
+    "types": [
+      "jasmine",
+      "node"
+    ]
+  }
+}

examples/basic-crud-application/angular-client/karma.conf.js

@@ -0,0 +1,44 @@
+// Karma configuration file, see link for more information
+// https://karma-runner.github.io/1.0/config/configuration-file.html
+
+module.exports = function (config) {
+  config.set({
+    basePath: '',
+    frameworks: ['jasmine', '@angular-devkit/build-angular'],
+    plugins: [
+      require('karma-jasmine'),
+      require('karma-chrome-launcher'),
+      require('karma-jasmine-html-reporter'),
+      require('karma-coverage'),
+      require('@angular-devkit/build-angular/plugins/karma')
+    ],
+    client: {
+      jasmine: {
+        // you can add configuration options for Jasmine here
+        // the possible options are listed at https://jasmine.github.io/api/edge/Configuration.html
+        // for example, you can disable the random execution with `random: false`
+        // or set a specific seed with `seed: 4321`
+      },
+      clearContext: false // leave Jasmine Spec Runner output visible in browser
+    },
+    jasmineHtmlReporter: {
+      suppressAll: true // removes the duplicated traces
+    },
+    coverageReporter: {
+      dir: require('path').join(__dirname, './coverage/angular-todomvc'),
+      subdir: '.',
+      reporters: [
+        { type: 'html' },
+        { type: 'text-summary' }
+      ]
+    },
+    reporters: ['progress', 'kjhtml'],
+    port: 9876,
+    colors: true,
+    logLevel: config.LOG_INFO,
+    autoWatch: true,
+    browsers: ['Chrome'],
+    singleRun: false,
+    restartOnFileChange: true
+  });
+};

examples/basic-crud-application/angular-client/package.json

@@ -0,0 +1,46 @@
+{
+  "name": "angular-todomvc",
+  "version": "0.0.0",
+  "scripts": {
+    "ng": "ng",
+    "start": "ng serve",
+    "build": "ng build",
+    "test": "ng test",
+    "lint": "ng lint",
+    "e2e": "ng e2e"
+  },
+  "private": true,
+  "dependencies": {
+    "@angular/animations": "~11.0.4",
+    "@angular/common": "~11.0.4",
+    "@angular/compiler": "~11.0.4",
+    "@angular/core": "~11.0.4",
+    "@angular/forms": "~11.0.4",
+    "@angular/platform-browser": "~11.0.4",
+    "@angular/platform-browser-dynamic": "~11.0.4",
+    "@angular/router": "~11.0.4",
+    "rxjs": "~6.6.0",
+    "socket.io-client": "^4.0.0",
+    "tslib": "^2.0.0",
+    "zone.js": "~0.10.2"
+  },
+  "devDependencies": {
+    "@angular-devkit/build-angular": "~0.1100.4",
+    "@angular/cli": "~11.0.4",
+    "@angular/compiler-cli": "~11.0.4",
+    "@types/jasmine": "~3.6.0",
+    "@types/node": "^12.11.1",
+    "codelyzer": "^6.0.0",
+    "jasmine-core": "~3.6.0",
+    "jasmine-spec-reporter": "~5.0.0",
+    "karma": "~5.1.0",
+    "karma-chrome-launcher": "~3.1.0",
+    "karma-coverage": "~2.0.3",
+    "karma-jasmine": "~4.0.0",
+    "karma-jasmine-html-reporter": "~1.5.0",
+    "protractor": "~7.0.0",
+    "ts-node": "~8.3.0",
+    "tslint": "~6.1.0",
+    "typescript": "~4.0.2"
+  }
+}

examples/basic-crud-application/angular-client/src/app/app.component.html

@@ -0,0 +1,23 @@
+<section class="todoapp">
+  <header class="header">
+    <h1>todos</h1>
+    <input class="new-todo" placeholder="What needs to be done?" autofocus="" [(ngModel)]="newTodoText" (keyup.enter)="addTodo()">
+  </header>
+  <section class="main" *ngIf="todoStore.todos.length > 0">
+    <input id="toggle-all" class="toggle-all" type="checkbox" *ngIf="todoStore.todos.length" #toggleall [checked]="todoStore.allCompleted()" (click)="todoStore.setAllTo(toggleall.checked)">
+    <ul class="todo-list">
+      <li *ngFor="let todo of todoStore.todos" [class.completed]="todo.completed" [class.editing]="todo.editing">
+        <div class="view">
+          <input class="toggle" type="checkbox" (click)="toggleCompletion(todo)" [checked]="todo.completed">
+          <label (dblclick)="editTodo(todo)">{{todo.title}}</label>
+          <button class="destroy" (click)="remove(todo)"></button>
+        </div>
+        <input class="edit" *ngIf="todo.editing" [value]="todo.title" #editedtodo (blur)="stopEditing(todo, editedtodo.value)" (keyup.enter)="updateEditingTodo(todo, editedtodo.value)" (keyup.escape)="cancelEditingTodo(todo)">
+      </li>
+    </ul>
+  </section>
+  <footer class="footer" *ngIf="todoStore.todos.length > 0">
+    <span class="todo-count"><strong>{{todoStore.getRemaining().length}}</strong> {{todoStore.getRemaining().length == 1 ? 'item' : 'items'}} left</span>
+    <button class="clear-completed" *ngIf="todoStore.getCompleted().length > 0" (click)="removeCompleted()">Clear completed</button>
+  </footer>
+</section>

examples/basic-crud-application/angular-client/src/app/app.component.spec.ts

@@ -0,0 +1,31 @@
+import { TestBed } from '@angular/core/testing';
+import { AppComponent } from './app.component';
+
+describe('AppComponent', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      declarations: [
+        AppComponent
+      ],
+    }).compileComponents();
+  });
+
+  it('should create the app', () => {
+    const fixture = TestBed.createComponent(AppComponent);
+    const app = fixture.componentInstance;
+    expect(app).toBeTruthy();
+  });
+
+  it(`should have as title 'angular-todomvc'`, () => {
+    const fixture = TestBed.createComponent(AppComponent);
+    const app = fixture.componentInstance;
+    expect(app.title).toEqual('angular-todomvc');
+  });
+
+  it('should render title', () => {
+    const fixture = TestBed.createComponent(AppComponent);
+    fixture.detectChanges();
+    const compiled = fixture.nativeElement;
+    expect(compiled.querySelector('.content span').textContent).toContain('angular-todomvc app is running!');
+  });
+});

examples/basic-crud-application/angular-client/src/app/app.component.ts

@@ -0,0 +1,59 @@
+import { Component } from '@angular/core';
+import { TodoStore, Todo } from './store';
+
+@Component({
+  selector: 'app-root',
+  templateUrl: './app.component.html',
+  styleUrls: ['./app.component.css']
+})
+export class AppComponent {
+  todoStore: TodoStore;
+  newTodoText = '';
+
+  constructor(todoStore: TodoStore) {
+    this.todoStore = todoStore;
+  }
+
+  stopEditing(todo: Todo, editedTitle: string) {
+    todo.title = editedTitle;
+    todo.editing = false;
+  }
+
+  cancelEditingTodo(todo: Todo) {
+    todo.editing = false;
+  }
+
+  updateEditingTodo(todo: Todo, editedTitle: string) {
+    editedTitle = editedTitle.trim();
+    todo.editing = false;
+
+    if (editedTitle.length === 0) {
+      return this.todoStore.remove(todo);
+    }
+
+    todo.title = editedTitle;
+  }
+
+  editTodo(todo: Todo) {
+    todo.editing = true;
+  }
+
+  removeCompleted() {
+    this.todoStore.removeCompleted();
+  }
+
+  toggleCompletion(todo: Todo) {
+    this.todoStore.toggleCompletion(todo);
+  }
+
+  remove(todo: Todo){
+    this.todoStore.remove(todo);
+  }
+
+  addTodo() {
+    if (this.newTodoText.trim().length) {
+      this.todoStore.add(this.newTodoText);
+      this.newTodoText = '';
+    }
+  }
+}

examples/basic-crud-application/angular-client/src/app/app.module.ts

@@ -0,0 +1,19 @@
+import { BrowserModule } from '@angular/platform-browser';
+import { NgModule } from '@angular/core';
+
+import { AppComponent } from './app.component';
+import { TodoStore } from './store';
+import { FormsModule } from "@angular/forms";
+
+@NgModule({
+  declarations: [
+    AppComponent
+  ],
+  imports: [
+    BrowserModule,
+    FormsModule
+  ],
+  providers: [TodoStore],
+  bootstrap: [AppComponent]
+})
+export class AppModule { }

examples/basic-crud-application/angular-client/src/app/store.ts

@@ -0,0 +1,140 @@
+import { io, Socket } from "socket.io-client";
+import { ClientEvents, ServerEvents } from "../../../server/lib/events";
+import { environment } from '../environments/environment';
+
+export interface Todo {
+  id: string,
+  title: string,
+  completed: boolean,
+  editing: boolean,
+  synced: boolean
+}
+
+const mapTodo = (todo: any) => {
+  return {
+    ...todo,
+    editing: false,
+    synced: true
+  }
+}
+
+export class TodoStore {
+  public todos: Array<Todo> = [];
+  private socket: Socket<ServerEvents, ClientEvents>;
+
+  constructor() {
+    this.socket = io(environment.serverUrl);
+
+    this.socket.on("connect", () => {
+      this.socket.emit("todo:list", (res) => {
+        if ("error" in res) {
+          // handle the error
+          return;
+        }
+        this.todos = res.data.map(mapTodo);
+      });
+    });
+
+    this.socket.on("todo:created", (todo) => {
+      this.todos.push(mapTodo(todo));
+    });
+
+    this.socket.on("todo:updated", (todo) => {
+      const existingTodo = this.todos.find(t => {
+        return t.id === todo.id
+      });
+      if (existingTodo) {
+        existingTodo.title = todo.title;
+        existingTodo.completed = todo.completed;
+      }
+    });
+
+    this.socket.on("todo:deleted", (id) => {
+      const index = this.todos.findIndex(t => {
+        return t.id === id
+      });
+      if (index !== -1) {
+        this.todos.splice(index, 1);
+      }
+    })
+  }
+
+  private getWithCompleted(completed: boolean) {
+    return this.todos.filter((todo: Todo) => todo.completed === completed);
+  }
+
+  allCompleted() {
+    return this.todos.length === this.getCompleted().length;
+  }
+
+  setAllTo(completed: boolean) {
+    this.todos.forEach(todo => {
+      todo.completed = completed;
+      todo.synced = false;
+      this.socket.emit("todo:update", todo, (res) => {
+        if (res && "error" in res) {
+          // handle the error
+          return;
+        }
+        todo.synced = true;
+      });
+    });
+  }
+
+  removeCompleted() {
+    this.getCompleted().forEach((todo) => {
+      this.socket.emit("todo:delete", todo.id, (res) => {
+        if (res && "error" in res) {
+          // handle the error
+        }
+      });
+    })
+    this.todos = this.getRemaining();
+  }
+
+  getRemaining() {
+    return this.getWithCompleted(false);
+  }
+
+  getCompleted() {
+    return this.getWithCompleted(true);
+  }
+
+  toggleCompletion(todo: Todo) {
+    todo.completed = !todo.completed;
+    todo.synced = false;
+    this.socket.emit("todo:update", todo, (res) => {
+      if (res && "error" in res) {
+        // handle the error
+        return;
+      }
+      todo.synced = true;
+    })
+  }
+
+  remove(todo: Todo) {
+    this.todos.splice(this.todos.indexOf(todo), 1);
+    this.socket.emit("todo:delete", todo.id, (res) => {
+      if (res && "error" in res) {
+        // handle the error
+      }
+    });
+  }
+
+  add(title: string) {
+    this.socket.emit("todo:create", { title, completed: false }, (res) => {
+      if ("error" in res) {
+        // handle the error
+        return;
+      }
+      this.todos.push({
+        id: res.data,
+        title,
+        completed: false,
+        editing: false,
+        synced: true
+      });
+    });
+  }
+}
+

examples/basic-crud-application/angular-client/src/environments/environment.prod.ts

@@ -0,0 +1,4 @@
+export const environment = {
+  production: true,
+  serverUrl: "https://my-custom-domain.com"
+};

examples/basic-crud-application/angular-client/src/environments/environment.ts

@@ -0,0 +1,17 @@
+// This file can be replaced during build by using the `fileReplacements` array.
+// `ng build --prod` replaces `environment.ts` with `environment.prod.ts`.
+// The list of file replacements can be found in `angular.json`.
+
+export const environment = {
+  production: false,
+  serverUrl: "http://localhost:3000"
+};
+
+/*
+ * For easier debugging in development mode, you can import the following file
+ * to ignore zone related error stack frames such as `zone.run`, `zoneDelegate.invokeTask`.
+ *
+ * This import should be commented out in production mode because it will have a negative impact
+ * on performance if an error is thrown.
+ */
+// import 'zone.js/dist/zone-error';  // Included with Angular CLI.

examples/basic-crud-application/angular-client/src/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>Angular Todo MVC</title>
+  <base href="/">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <link rel="icon" type="image/x-icon" href="favicon.ico">
+</head>
+<body>
+  <app-root></app-root>
+</body>
+</html>

examples/basic-crud-application/angular-client/src/main.ts

@@ -0,0 +1,12 @@
+import { enableProdMode } from '@angular/core';
+import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
+
+import { AppModule } from './app/app.module';
+import { environment } from './environments/environment';
+
+if (environment.production) {
+  enableProdMode();
+}
+
+platformBrowserDynamic().bootstrapModule(AppModule)
+  .catch(err => console.error(err));

examples/basic-crud-application/angular-client/src/polyfills.ts

@@ -0,0 +1,63 @@
+/**
+ * This file includes polyfills needed by Angular and is loaded before the app.
+ * You can add your own extra polyfills to this file.
+ *
+ * This file is divided into 2 sections:
+ *   1. Browser polyfills. These are applied before loading ZoneJS and are sorted by browsers.
+ *   2. Application imports. Files imported after ZoneJS that should be loaded before your main
+ *      file.
+ *
+ * The current setup is for so-called "evergreen" browsers; the last versions of browsers that
+ * automatically update themselves. This includes Safari >= 10, Chrome >= 55 (including Opera),
+ * Edge >= 13 on the desktop, and iOS 10 and Chrome on mobile.
+ *
+ * Learn more in https://angular.io/guide/browser-support
+ */
+
+/***************************************************************************************************
+ * BROWSER POLYFILLS
+ */
+
+/** IE11 requires the following for NgClass support on SVG elements */
+// import 'classlist.js';  // Run `npm install --save classlist.js`.
+
+/**
+ * Web Animations `@angular/platform-browser/animations`
+ * Only required if AnimationBuilder is used within the application and using IE/Edge or Safari.
+ * Standard animation support in Angular DOES NOT require any polyfills (as of Angular 6.0).
+ */
+// import 'web-animations-js';  // Run `npm install --save web-animations-js`.
+
+/**
+ * By default, zone.js will patch all possible macroTask and DomEvents
+ * user can disable parts of macroTask/DomEvents patch by setting following flags
+ * because those flags need to be set before `zone.js` being loaded, and webpack
+ * will put import in the top of bundle, so user need to create a separate file
+ * in this directory (for example: zone-flags.ts), and put the following flags
+ * into that file, and then add the following code before importing zone.js.
+ * import './zone-flags';
+ *
+ * The flags allowed in zone-flags.ts are listed here.
+ *
+ * The following flags will work for all browsers.
+ *
+ * (window as any).__Zone_disable_requestAnimationFrame = true; // disable patch requestAnimationFrame
+ * (window as any).__Zone_disable_on_property = true; // disable patch onProperty such as onclick
+ * (window as any).__zone_symbol__UNPATCHED_EVENTS = ['scroll', 'mousemove']; // disable patch specified eventNames
+ *
+ *  in IE/Edge developer tools, the addEventListener will also be wrapped by zone.js
+ *  with the following flag, it will bypass `zone.js` patch for IE/Edge
+ *
+ *  (window as any).__Zone_enable_cross_context_check = true;
+ *
+ */
+
+/***************************************************************************************************
+ * Zone JS is required by default for Angular itself.
+ */
+import 'zone.js/dist/zone';  // Included with Angular CLI.
+
+
+/***************************************************************************************************
+ * APPLICATION IMPORTS
+ */

examples/basic-crud-application/angular-client/src/styles.css

@@ -0,0 +1,381 @@
+/* imported from node_modules/todomvc-app-css/index.css */
+html,
+body {
+  margin: 0;
+  padding: 0;
+}
+
+button {
+  margin: 0;
+  padding: 0;
+  border: 0;
+  background: none;
+  font-size: 100%;
+  vertical-align: baseline;
+  font-family: inherit;
+  font-weight: inherit;
+  color: inherit;
+  -webkit-appearance: none;
+  appearance: none;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+body {
+  font: 14px 'Helvetica Neue', Helvetica, Arial, sans-serif;
+  line-height: 1.4em;
+  background: #f5f5f5;
+  color: #111111;
+  min-width: 230px;
+  max-width: 550px;
+  margin: 0 auto;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+  font-weight: 300;
+}
+
+:focus {
+  outline: 0;
+}
+
+.hidden {
+  display: none;
+}
+
+.todoapp {
+  background: #fff;
+  margin: 130px 0 40px 0;
+  position: relative;
+  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2),
+  0 25px 50px 0 rgba(0, 0, 0, 0.1);
+}
+
+.todoapp input::-webkit-input-placeholder {
+  font-style: italic;
+  font-weight: 300;
+  color: rgba(0, 0, 0, 0.4);
+}
+
+.todoapp input::-moz-placeholder {
+  font-style: italic;
+  font-weight: 300;
+  color: rgba(0, 0, 0, 0.4);
+}
+
+.todoapp input::input-placeholder {
+  font-style: italic;
+  font-weight: 300;
+  color: rgba(0, 0, 0, 0.4);
+}
+
+.todoapp h1 {
+  position: absolute;
+  top: -140px;
+  width: 100%;
+  font-size: 80px;
+  font-weight: 200;
+  text-align: center;
+  color: #b83f45;
+  -webkit-text-rendering: optimizeLegibility;
+  -moz-text-rendering: optimizeLegibility;
+  text-rendering: optimizeLegibility;
+}
+
+.new-todo,
+.edit {
+  position: relative;
+  margin: 0;
+  width: 100%;
+  font-size: 24px;
+  font-family: inherit;
+  font-weight: inherit;
+  line-height: 1.4em;
+  color: inherit;
+  padding: 6px;
+  border: 1px solid #999;
+  box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
+  box-sizing: border-box;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+.new-todo {
+  padding: 16px 16px 16px 60px;
+  border: none;
+  background: rgba(0, 0, 0, 0.003);
+  box-shadow: inset 0 -2px 1px rgba(0,0,0,0.03);
+}
+
+.main {
+  position: relative;
+  z-index: 2;
+  border-top: 1px solid #e6e6e6;
+}
+
+.toggle-all {
+  width: 1px;
+  height: 1px;
+  border: none; /* Mobile Safari */
+  opacity: 0;
+  position: absolute;
+  right: 100%;
+  bottom: 100%;
+}
+
+.toggle-all + label {
+  width: 60px;
+  height: 34px;
+  font-size: 0;
+  position: absolute;
+  top: -52px;
+  left: -13px;
+  -webkit-transform: rotate(90deg);
+  transform: rotate(90deg);
+}
+
+.toggle-all + label:before {
+  content: '❯';
+  font-size: 22px;
+  color: #e6e6e6;
+  padding: 10px 27px 10px 27px;
+}
+
+.toggle-all:checked + label:before {
+  color: #737373;
+}
+
+.todo-list {
+  margin: 0;
+  padding: 0;
+  list-style: none;
+}
+
+.todo-list li {
+  position: relative;
+  font-size: 24px;
+  border-bottom: 1px solid #ededed;
+}
+
+.todo-list li:last-child {
+  border-bottom: none;
+}
+
+.todo-list li.editing {
+  border-bottom: none;
+  padding: 0;
+}
+
+.todo-list li.editing .edit {
+  display: block;
+  width: calc(100% - 43px);
+  padding: 12px 16px;
+  margin: 0 0 0 43px;
+}
+
+.todo-list li.editing .view {
+  display: none;
+}
+
+.todo-list li .toggle {
+  text-align: center;
+  width: 40px;
+  /* auto, since non-WebKit browsers doesn't support input styling */
+  height: auto;
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  margin: auto 0;
+  border: none; /* Mobile Safari */
+  -webkit-appearance: none;
+  appearance: none;
+}
+
+.todo-list li .toggle {
+  opacity: 0;
+}
+
+.todo-list li .toggle + label {
+  /*
+    Firefox requires `#` to be escaped - https://bugzilla.mozilla.org/show_bug.cgi?id=922433
+    IE and Edge requires *everything* to be escaped to render, so we do that instead of just the `#` - https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7157459/
+  */
+  background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23ededed%22%20stroke-width%3D%223%22/%3E%3C/svg%3E');
+  background-repeat: no-repeat;
+  background-position: center left;
+}
+
+.todo-list li .toggle:checked + label {
+  background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23bddad5%22%20stroke-width%3D%223%22/%3E%3Cpath%20fill%3D%22%235dc2af%22%20d%3D%22M72%2025L42%2071%2027%2056l-4%204%2020%2020%2034-52z%22/%3E%3C/svg%3E');
+}
+
+.todo-list li label {
+  word-break: break-all;
+  padding: 15px 15px 15px 60px;
+  display: block;
+  line-height: 1.2;
+  transition: color 0.4s;
+  font-weight: 400;
+  color: #4d4d4d;
+}
+
+.todo-list li.completed label {
+  color: #cdcdcd;
+  text-decoration: line-through;
+}
+
+.todo-list li .destroy {
+  display: none;
+  position: absolute;
+  top: 0;
+  right: 10px;
+  bottom: 0;
+  width: 40px;
+  height: 40px;
+  margin: auto 0;
+  font-size: 30px;
+  color: #cc9a9a;
+  margin-bottom: 11px;
+  transition: color 0.2s ease-out;
+}
+
+.todo-list li .destroy:hover {
+  color: #af5b5e;
+}
+
+.todo-list li .destroy:after {
+  content: '×';
+}
+
+.todo-list li:hover .destroy {
+  display: block;
+}
+
+.todo-list li .edit {
+  display: none;
+}
+
+.todo-list li.editing:last-child {
+  margin-bottom: -1px;
+}
+
+.footer {
+  padding: 10px 15px;
+  height: 20px;
+  text-align: center;
+  font-size: 15px;
+  border-top: 1px solid #e6e6e6;
+}
+
+.footer:before {
+  content: '';
+  position: absolute;
+  right: 0;
+  bottom: 0;
+  left: 0;
+  height: 50px;
+  overflow: hidden;
+  box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2),
+  0 8px 0 -3px #f6f6f6,
+  0 9px 1px -3px rgba(0, 0, 0, 0.2),
+  0 16px 0 -6px #f6f6f6,
+  0 17px 2px -6px rgba(0, 0, 0, 0.2);
+}
+
+.todo-count {
+  float: left;
+  text-align: left;
+}
+
+.todo-count strong {
+  font-weight: 300;
+}
+
+.filters {
+  margin: 0;
+  padding: 0;
+  list-style: none;
+  position: absolute;
+  right: 0;
+  left: 0;
+}
+
+.filters li {
+  display: inline;
+}
+
+.filters li a {
+  color: inherit;
+  margin: 3px;
+  padding: 3px 7px;
+  text-decoration: none;
+  border: 1px solid transparent;
+  border-radius: 3px;
+}
+
+.filters li a:hover {
+  border-color: rgba(175, 47, 47, 0.1);
+}
+
+.filters li a.selected {
+  border-color: rgba(175, 47, 47, 0.2);
+}
+
+.clear-completed,
+html .clear-completed:active {
+  float: right;
+  position: relative;
+  line-height: 20px;
+  text-decoration: none;
+  cursor: pointer;
+}
+
+.clear-completed:hover {
+  text-decoration: underline;
+}
+
+.info {
+  margin: 65px auto 0;
+  color: #4d4d4d;
+  font-size: 11px;
+  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
+  text-align: center;
+}
+
+.info p {
+  line-height: 1;
+}
+
+.info a {
+  color: inherit;
+  text-decoration: none;
+  font-weight: 400;
+}
+
+.info a:hover {
+  text-decoration: underline;
+}
+
+/*
+	Hack to remove background from Mobile Safari.
+	Can't use it globally since it destroys checkboxes in Firefox
+*/
+@media screen and (-webkit-min-device-pixel-ratio:0) {
+  .toggle-all,
+  .todo-list li .toggle {
+    background: none;
+  }
+
+  .todo-list li .toggle {
+    height: 40px;
+  }
+}
+
+@media (max-width: 430px) {
+  .footer {
+    height: 50px;
+  }
+
+  .filters {
+    bottom: 10px;
+  }
+}

examples/basic-crud-application/angular-client/src/test.ts

@@ -0,0 +1,25 @@
+// This file is required by karma.conf.js and loads recursively all the .spec and framework files
+
+import 'zone.js/dist/zone-testing';
+import { getTestBed } from '@angular/core/testing';
+import {
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting
+} from '@angular/platform-browser-dynamic/testing';
+
+declare const require: {
+  context(path: string, deep?: boolean, filter?: RegExp): {
+    keys(): string[];
+    <T>(id: string): T;
+  };
+};
+
+// First, initialize the Angular testing environment.
+getTestBed().initTestEnvironment(
+  BrowserDynamicTestingModule,
+  platformBrowserDynamicTesting()
+);
+// Then we find all the tests.
+const context = require.context('./', true, /\.spec\.ts$/);
+// And load the modules.
+context.keys().map(context);

examples/basic-crud-application/angular-client/tsconfig.app.json

@@ -0,0 +1,15 @@
+/* To learn more about this file see: https://angular.io/config/tsconfig. */
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./out-tsc/app",
+    "types": []
+  },
+  "files": [
+    "src/main.ts",
+    "src/polyfills.ts"
+  ],
+  "include": [
+    "src/**/*.d.ts"
+  ]
+}

examples/basic-crud-application/angular-client/tsconfig.json

@@ -0,0 +1,29 @@
+/* To learn more about this file see: https://angular.io/config/tsconfig. */
+{
+  "compileOnSave": false,
+  "compilerOptions": {
+    "baseUrl": "./",
+    "outDir": "./dist/out-tsc",
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true,
+    "sourceMap": true,
+    "declaration": false,
+    "downlevelIteration": true,
+    "experimentalDecorators": true,
+    "moduleResolution": "node",
+    "importHelpers": true,
+    "target": "es2015",
+    "module": "es2020",
+    "lib": [
+      "es2018",
+      "dom"
+    ]
+  },
+  "angularCompilerOptions": {
+    "strictInjectionParameters": true,
+    "strictInputAccessModifiers": true,
+    "strictTemplates": true
+  }
+}

examples/basic-crud-application/angular-client/tsconfig.spec.json

@@ -0,0 +1,18 @@
+/* To learn more about this file see: https://angular.io/config/tsconfig. */
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./out-tsc/spec",
+    "types": [
+      "jasmine"
+    ]
+  },
+  "files": [
+    "src/test.ts",
+    "src/polyfills.ts"
+  ],
+  "include": [
+    "src/**/*.spec.ts",
+    "src/**/*.d.ts"
+  ]
+}

examples/basic-crud-application/angular-client/tslint.json

@@ -0,0 +1,152 @@
+{
+  "extends": "tslint:recommended",
+  "rulesDirectory": [
+    "codelyzer"
+  ],
+  "rules": {
+    "align": {
+      "options": [
+        "parameters",
+        "statements"
+      ]
+    },
+    "array-type": false,
+    "arrow-return-shorthand": true,
+    "curly": true,
+    "deprecation": {
+      "severity": "warning"
+    },
+    "eofline": true,
+    "import-blacklist": [
+      true,
+      "rxjs/Rx"
+    ],
+    "import-spacing": true,
+    "indent": {
+      "options": [
+        "spaces"
+      ]
+    },
+    "max-classes-per-file": false,
+    "max-line-length": [
+      true,
+      140
+    ],
+    "member-ordering": [
+      true,
+      {
+        "order": [
+          "static-field",
+          "instance-field",
+          "static-method",
+          "instance-method"
+        ]
+      }
+    ],
+    "no-console": [
+      true,
+      "debug",
+      "info",
+      "time",
+      "timeEnd",
+      "trace"
+    ],
+    "no-empty": false,
+    "no-inferrable-types": [
+      true,
+      "ignore-params"
+    ],
+    "no-non-null-assertion": true,
+    "no-redundant-jsdoc": true,
+    "no-switch-case-fall-through": true,
+    "no-var-requires": false,
+    "object-literal-key-quotes": [
+      true,
+      "as-needed"
+    ],
+    "quotemark": [
+      true,
+      "single"
+    ],
+    "semicolon": {
+      "options": [
+        "always"
+      ]
+    },
+    "space-before-function-paren": {
+      "options": {
+        "anonymous": "never",
+        "asyncArrow": "always",
+        "constructor": "never",
+        "method": "never",
+        "named": "never"
+      }
+    },
+    "typedef": [
+      true,
+      "call-signature"
+    ],
+    "typedef-whitespace": {
+      "options": [
+        {
+          "call-signature": "nospace",
+          "index-signature": "nospace",
+          "parameter": "nospace",
+          "property-declaration": "nospace",
+          "variable-declaration": "nospace"
+        },
+        {
+          "call-signature": "onespace",
+          "index-signature": "onespace",
+          "parameter": "onespace",
+          "property-declaration": "onespace",
+          "variable-declaration": "onespace"
+        }
+      ]
+    },
+    "variable-name": {
+      "options": [
+        "ban-keywords",
+        "check-format",
+        "allow-pascal-case"
+      ]
+    },
+    "whitespace": {
+      "options": [
+        "check-branch",
+        "check-decl",
+        "check-operator",
+        "check-separator",
+        "check-type",
+        "check-typecast"
+      ]
+    },
+    "component-class-suffix": true,
+    "contextual-lifecycle": true,
+    "directive-class-suffix": true,
+    "no-conflicting-lifecycle": true,
+    "no-host-metadata-property": true,
+    "no-input-rename": true,
+    "no-inputs-metadata-property": true,
+    "no-output-native": true,
+    "no-output-on-prefix": true,
+    "no-output-rename": true,
+    "no-outputs-metadata-property": true,
+    "template-banana-in-box": true,
+    "template-no-negated-async": true,
+    "use-lifecycle-interface": true,
+    "use-pipe-transform-interface": true,
+    "directive-selector": [
+      true,
+      "attribute",
+      "app",
+      "camelCase"
+    ],
+    "component-selector": [
+      true,
+      "element",
+      "app",
+      "kebab-case"
+    ]
+  }
+}

examples/basic-crud-application/server-postgres-cluster/README.md

@@ -0,0 +1,16 @@
+
+A basic TODO project.
+
+| Characteristic |                                                                                           |
+|----------------|-------------------------------------------------------------------------------------------|
+| Language       | plain JavaScript                                                                          |
+| Database       | Postgres, with the [Postgres adapter](https://socket.io/docs/v4/postgres-adapter/)        |
+| Cluster?       | Yes, with the [`@socket.io/sticky`](https://github.com/socketio/socket.io-sticky) module) |
+
+## Usage
+
+```
+$ docker-compose up -d
+$ npm install
+$ npm start
+```

examples/basic-crud-application/server-postgres-cluster/docker-compose.yml

@@ -0,0 +1,9 @@
+version: "3"
+
+services:
+  postgres:
+    image: postgres:12
+    ports:
+      - "5432:5432"
+    environment:
+      POSTGRES_PASSWORD: "changeit"

examples/basic-crud-application/server-postgres-cluster/lib/app.js

@@ -0,0 +1,26 @@
+import { Server } from "socket.io";
+import createTodoHandlers from "./todo-management/todo.handlers.js";
+import { setupWorker } from "@socket.io/sticky";
+import { createAdapter } from "@socket.io/postgres-adapter";
+
+export function createApplication(httpServer, components, serverOptions = {}) {
+  const io = new Server(httpServer, serverOptions);
+
+  const { createTodo, readTodo, updateTodo, deleteTodo, listTodo } =
+    createTodoHandlers(components);
+
+  io.on("connection", (socket) => {
+    socket.on("todo:create", createTodo);
+    socket.on("todo:read", readTodo);
+    socket.on("todo:update", updateTodo);
+    socket.on("todo:delete", deleteTodo);
+    socket.on("todo:list", listTodo);
+  });
+
+  // enable sticky session in the cluster (to remove in standalone mode)
+  setupWorker(io);
+
+  io.adapter(createAdapter(components.connectionPool));
+
+  return io;
+}

examples/basic-crud-application/server-postgres-cluster/lib/cluster.js

@@ -0,0 +1,28 @@
+import cluster from "cluster";
+import { createServer } from "http";
+import { setupMaster } from "@socket.io/sticky";
+import { cpus } from "os";
+
+if (cluster.isMaster) {
+  console.log(`Master ${process.pid} is running`);
+  const httpServer = createServer();
+
+  setupMaster(httpServer, {
+    loadBalancingMethod: "least-connection",
+  });
+
+  httpServer.listen(3000);
+
+  for (let i = 0; i < cpus().length; i++) {
+    cluster.fork();
+  }
+
+  cluster.on("exit", (worker) => {
+    console.log(`Worker ${worker.process.pid} died`);
+    cluster.fork();
+  });
+} else {
+  console.log(`Worker ${process.pid} started`);
+
+  import("./index.js");
+}

examples/basic-crud-application/server-postgres-cluster/lib/index.js

@@ -0,0 +1,51 @@
+import { createServer } from "http";
+import { createApplication } from "./app.js";
+import { Sequelize } from "sequelize";
+import pg from "pg";
+import { PostgresTodoRepository } from "./todo-management/todo.repository.js";
+
+const httpServer = createServer();
+
+const sequelize = new Sequelize("postgres", "postgres", "changeit", {
+  dialect: "postgres",
+});
+
+const connectionPool = new pg.Pool({
+  user: "postgres",
+  host: "localhost",
+  database: "postgres",
+  password: "changeit",
+  port: 5432,
+});
+
+createApplication(
+  httpServer,
+  {
+    connectionPool,
+    todoRepository: new PostgresTodoRepository(sequelize),
+  },
+  {
+    cors: {
+      origin: ["http://localhost:4200"],
+    },
+  }
+);
+
+const main = async () => {
+  // create the tables if they do not exist already
+  await sequelize.sync();
+
+  // create the table needed by the postgres adapter
+  await connectionPool.query(`
+    CREATE TABLE IF NOT EXISTS socket_io_attachments (
+        id          bigserial UNIQUE,
+        created_at  timestamptz DEFAULT NOW(),
+        payload     bytea
+    );
+  `);
+
+  // uncomment when running in standalone mode
+  // httpServer.listen(3000);
+};
+
+main();

examples/basic-crud-application/server-postgres-cluster/lib/todo-management/todo.handlers.js

@@ -0,0 +1,140 @@
+import { Errors, mapErrorDetails, sanitizeErrorMessage } from "../util.js";
+import { v4 as uuid } from "uuid";
+import Joi from "joi";
+
+const idSchema = Joi.string().guid({
+  version: "uuidv4",
+});
+
+const todoSchema = Joi.object({
+  id: idSchema.alter({
+    create: (schema) => schema.forbidden(),
+    update: (schema) => schema.required(),
+  }),
+  title: Joi.string().max(256).required(),
+  completed: Joi.boolean().required(),
+});
+
+export default function (components) {
+  const { todoRepository } = components;
+  return {
+    createTodo: async function (payload, callback) {
+      const socket = this;
+
+      // validate the payload
+      const { error, value } = todoSchema.tailor("create").validate(payload, {
+        abortEarly: false,
+        stripUnknown: true,
+      });
+
+      if (error) {
+        return callback({
+          error: Errors.INVALID_PAYLOAD,
+          errorDetails: mapErrorDetails(error.details),
+        });
+      }
+
+      value.id = uuid();
+
+      // persist the entity
+      try {
+        await todoRepository.save(value);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      // acknowledge the creation
+      callback({
+        data: value.id,
+      });
+
+      // notify the other users
+      socket.broadcast.emit("todo:created", value);
+    },
+
+    readTodo: async function (id, callback) {
+      const { error } = idSchema.validate(id);
+
+      if (error) {
+        return callback({
+          error: Errors.ENTITY_NOT_FOUND,
+        });
+      }
+
+      try {
+        const todo = await todoRepository.findById(id);
+        callback({
+          data: todo,
+        });
+      } catch (e) {
+        callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+    },
+
+    updateTodo: async function (payload, callback) {
+      const socket = this;
+
+      const { error, value } = todoSchema.tailor("update").validate(payload, {
+        abortEarly: false,
+        stripUnknown: true,
+      });
+
+      if (error) {
+        return callback({
+          error: Errors.INVALID_PAYLOAD,
+          errorDetails: mapErrorDetails(error.details),
+        });
+      }
+
+      try {
+        await todoRepository.save(value);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      callback();
+      socket.broadcast.emit("todo:updated", value);
+    },
+
+    deleteTodo: async function (id, callback) {
+      const socket = this;
+
+      const { error } = idSchema.validate(id);
+
+      if (error) {
+        return callback({
+          error: Errors.ENTITY_NOT_FOUND,
+        });
+      }
+
+      try {
+        await todoRepository.deleteById(id);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      callback();
+      socket.broadcast.emit("todo:deleted", id);
+    },
+
+    listTodo: async function (callback) {
+      try {
+        callback({
+          data: await todoRepository.findAll(),
+        });
+      } catch (e) {
+        callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+    },
+  };
+}

examples/basic-crud-application/server-postgres-cluster/lib/todo-management/todo.repository.js

@@ -0,0 +1,74 @@
+import { Errors } from "../util.js";
+import { Model, DataTypes } from "sequelize";
+
+class CrudRepository {
+  findAll() {}
+  findById(id) {}
+  save(entity) {}
+  deleteById(id) {}
+}
+
+export class TodoRepository extends CrudRepository {}
+
+class Todo extends Model {}
+
+export class PostgresTodoRepository extends TodoRepository {
+  constructor(sequelize) {
+    super();
+    this.sequelize = sequelize;
+
+    Todo.init(
+      {
+        id: {
+          type: DataTypes.STRING,
+          primaryKey: true,
+          allowNull: false,
+        },
+        title: {
+          type: DataTypes.STRING,
+        },
+        completed: {
+          type: DataTypes.BOOLEAN,
+        },
+      },
+      {
+        sequelize,
+        tableName: "todos",
+      }
+    );
+  }
+
+  findAll() {
+    return this.sequelize.transaction((transaction) => {
+      return Todo.findAll({ transaction });
+    });
+  }
+
+  async findById(id) {
+    return this.sequelize.transaction(async (transaction) => {
+      const todo = await Todo.findByPk(id, { transaction });
+
+      if (!todo) {
+        throw Errors.ENTITY_NOT_FOUND;
+      }
+
+      return todo;
+    });
+  }
+
+  save(entity) {
+    return this.sequelize.transaction((transaction) => {
+      return Todo.upsert(entity, { transaction });
+    });
+  }
+
+  async deleteById(id) {
+    return this.sequelize.transaction(async (transaction) => {
+      const count = await Todo.destroy({ where: { id }, transaction });
+
+      if (count === 0) {
+        throw Errors.ENTITY_NOT_FOUND;
+      }
+    });
+  }
+}

examples/basic-crud-application/server-postgres-cluster/lib/util.js

@@ -0,0 +1,22 @@
+export const Errors = {
+  ENTITY_NOT_FOUND: "entity not found",
+  INVALID_PAYLOAD: "invalid payload",
+};
+
+const errorValues = Object.values(Errors);
+
+export function sanitizeErrorMessage(message) {
+  if (typeof message === "string" && errorValues.includes(message)) {
+    return message;
+  } else {
+    return "an unknown error has occurred";
+  }
+}
+
+export function mapErrorDetails(details) {
+  return details.map((item) => ({
+    message: item.message,
+    path: item.path,
+    type: item.type,
+  }));
+}

examples/basic-crud-application/server-postgres-cluster/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "basic-crud-server",
+  "version": "0.0.1",
+  "description": "Server for the Basic CRUD Socket.IO example (with Postgres and multiple Socket.IO servers)",
+  "main": "lib/cluster.js",
+  "type": "module",
+  "scripts": {
+    "start": "node lib/cluster.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/socketio/socket.io.git"
+  },
+  "author": "Damien Arrachequesne <damien.arrachequesne@gmail.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/socketio/socket.io/issues"
+  },
+  "homepage": "https://github.com/socketio/socket.io#readme",
+  "dependencies": {
+    "@socket.io/postgres-adapter": "^0.2.0",
+    "@socket.io/sticky": "^1.0.1",
+    "joi": "^17.4.0",
+    "pg": "^8.7.3",
+    "pg-hstore": "^2.3.4",
+    "sequelize": "^6.18.0",
+    "socket.io": "^4.0.1",
+    "uuid": "^8.3.2"
+  }
+}

examples/basic-crud-application/server/lib/app.ts

@@ -0,0 +1,35 @@
+import { Server as HttpServer } from "http";
+import { Server, ServerOptions } from "socket.io";
+import { ClientEvents, ServerEvents } from "./events";
+import { TodoRepository } from "./todo-management/todo.repository";
+import createTodoHandlers from "./todo-management/todo.handlers";
+
+export interface Components {
+  todoRepository: TodoRepository;
+}
+
+export function createApplication(
+  httpServer: HttpServer,
+  components: Components,
+  serverOptions: Partial<ServerOptions> = {}
+): Server<ClientEvents, ServerEvents> {
+  const io = new Server<ClientEvents, ServerEvents>(httpServer, serverOptions);
+
+  const {
+    createTodo,
+    readTodo,
+    updateTodo,
+    deleteTodo,
+    listTodo,
+  } = createTodoHandlers(components);
+
+  io.on("connection", (socket) => {
+    socket.on("todo:create", createTodo);
+    socket.on("todo:read", readTodo);
+    socket.on("todo:update", updateTodo);
+    socket.on("todo:delete", deleteTodo);
+    socket.on("todo:list", listTodo);
+  });
+
+  return io;
+}

examples/basic-crud-application/server/lib/events.ts

@@ -0,0 +1,37 @@
+import { Todo, TodoID } from "./todo-management/todo.repository";
+import { ValidationErrorItem } from "joi";
+
+interface Error {
+  error: string;
+  errorDetails?: ValidationErrorItem[];
+}
+
+interface Success<T> {
+  data: T;
+}
+
+export type Response<T> = Error | Success<T>;
+
+export interface ServerEvents {
+  "todo:created": (todo: Todo) => void;
+  "todo:updated": (todo: Todo) => void;
+  "todo:deleted": (id: TodoID) => void;
+}
+
+export interface ClientEvents {
+  "todo:list": (callback: (res: Response<Todo[]>) => void) => void;
+
+  "todo:create": (
+    payload: Omit<Todo, "id">,
+    callback: (res: Response<TodoID>) => void
+  ) => void;
+
+  "todo:read": (id: TodoID, callback: (res: Response<Todo>) => void) => void;
+
+  "todo:update": (
+    payload: Todo,
+    callback: (res?: Response<void>) => void
+  ) => void;
+
+  "todo:delete": (id: TodoID, callback: (res?: Response<void>) => void) => void;
+}

examples/basic-crud-application/server/lib/index.ts

@@ -0,0 +1,19 @@
+import { createServer } from "http";
+import { createApplication } from "./app";
+import { InMemoryTodoRepository } from "./todo-management/todo.repository";
+
+const httpServer = createServer();
+
+createApplication(
+  httpServer,
+  {
+    todoRepository: new InMemoryTodoRepository(),
+  },
+  {
+    cors: {
+      origin: ["http://localhost:4200"],
+    },
+  }
+);
+
+httpServer.listen(3000);

examples/basic-crud-application/server/lib/todo-management/todo.handlers.ts

@@ -0,0 +1,159 @@
+import { Errors, mapErrorDetails, sanitizeErrorMessage } from "../util";
+import { v4 as uuid } from "uuid";
+import { Components } from "../app";
+import Joi = require("joi");
+import { Todo, TodoID } from "./todo.repository";
+import { ClientEvents, Response, ServerEvents } from "../events";
+import { Socket } from "socket.io";
+
+const idSchema = Joi.string().guid({
+  version: "uuidv4",
+});
+
+const todoSchema = Joi.object({
+  id: idSchema.alter({
+    create: (schema) => schema.forbidden(),
+    update: (schema) => schema.required(),
+  }),
+  title: Joi.string().max(256).required(),
+  completed: Joi.boolean().required(),
+});
+
+export default function (components: Components) {
+  const { todoRepository } = components;
+  return {
+    createTodo: async function (
+      payload: Omit<Todo, "id">,
+      callback: (res: Response<TodoID>) => void
+    ) {
+      // @ts-ignore
+      const socket: Socket<ClientEvents, ServerEvents> = this;
+
+      // validate the payload
+      const { error, value } = todoSchema.tailor("create").validate(payload, {
+        abortEarly: false,
+        stripUnknown: true,
+      });
+
+      if (error) {
+        return callback({
+          error: Errors.INVALID_PAYLOAD,
+          errorDetails: mapErrorDetails(error.details),
+        });
+      }
+
+      value.id = uuid();
+
+      // persist the entity
+      try {
+        await todoRepository.save(value);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      // acknowledge the creation
+      callback({
+        data: value.id,
+      });
+
+      // notify the other users
+      socket.broadcast.emit("todo:created", value);
+    },
+
+    readTodo: async function (
+      id: TodoID,
+      callback: (res: Response<Todo>) => void
+    ) {
+      const { error } = idSchema.validate(id);
+
+      if (error) {
+        return callback({
+          error: Errors.ENTITY_NOT_FOUND,
+        });
+      }
+
+      try {
+        const todo = await todoRepository.findById(id);
+        callback({
+          data: todo,
+        });
+      } catch (e) {
+        callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+    },
+
+    updateTodo: async function (
+      payload: Todo,
+      callback: (res?: Response<void>) => void
+    ) {
+      // @ts-ignore
+      const socket: Socket<ClientEvents, ServerEvents> = this;
+
+      const { error, value } = todoSchema.tailor("update").validate(payload, {
+        abortEarly: false,
+        stripUnknown: true,
+      });
+
+      if (error) {
+        return callback({
+          error: Errors.INVALID_PAYLOAD,
+          errorDetails: mapErrorDetails(error.details),
+        });
+      }
+
+      try {
+        await todoRepository.save(value);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      callback();
+      socket.broadcast.emit("todo:updated", value);
+    },
+
+    deleteTodo: async function (
+      id: TodoID,
+      callback: (res?: Response<void>) => void
+    ) {
+      // @ts-ignore
+      const socket: Socket<ClientEvents, ServerEvents> = this;
+
+      const { error } = idSchema.validate(id);
+
+      if (error) {
+        return callback({
+          error: Errors.ENTITY_NOT_FOUND,
+        });
+      }
+
+      try {
+        await todoRepository.deleteById(id);
+      } catch (e) {
+        return callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+
+      callback();
+      socket.broadcast.emit("todo:deleted", id);
+    },
+
+    listTodo: async function (callback: (res: Response<Todo[]>) => void) {
+      try {
+        callback({
+          data: await todoRepository.findAll(),
+        });
+      } catch (e) {
+        callback({
+          error: sanitizeErrorMessage(e),
+        });
+      }
+    },
+  };
+}

examples/basic-crud-application/server/lib/todo-management/todo.repository.ts

@@ -0,0 +1,49 @@
+import { Errors } from "../util";
+
+abstract class CrudRepository<T, ID> {
+  abstract findAll(): Promise<T[]>;
+  abstract findById(id: ID): Promise<T>;
+  abstract save(entity: T): Promise<void>;
+  abstract deleteById(id: ID): Promise<void>;
+}
+
+export type TodoID = string;
+
+export interface Todo {
+  id: TodoID;
+  completed: boolean;
+  title: string;
+}
+
+export abstract class TodoRepository extends CrudRepository<Todo, TodoID> {}
+
+export class InMemoryTodoRepository extends TodoRepository {
+  private readonly todos: Map<TodoID, Todo> = new Map();
+
+  findAll(): Promise<Todo[]> {
+    const entities = Array.from(this.todos.values());
+    return Promise.resolve(entities);
+  }
+
+  findById(id: TodoID): Promise<Todo> {
+    if (this.todos.has(id)) {
+      return Promise.resolve(this.todos.get(id)!);
+    } else {
+      return Promise.reject(Errors.ENTITY_NOT_FOUND);
+    }
+  }
+
+  save(entity: Todo): Promise<void> {
+    this.todos.set(entity.id, entity);
+    return Promise.resolve();
+  }
+
+  deleteById(id: TodoID): Promise<void> {
+    const deleted = this.todos.delete(id);
+    if (deleted) {
+      return Promise.resolve();
+    } else {
+      return Promise.reject(Errors.ENTITY_NOT_FOUND);
+    }
+  }
+}

examples/basic-crud-application/server/lib/util.ts

@@ -0,0 +1,24 @@
+import { ValidationErrorItem } from "joi";
+
+export enum Errors {
+  ENTITY_NOT_FOUND = "entity not found",
+  INVALID_PAYLOAD = "invalid payload",
+}
+
+const errorValues: string[] = Object.values(Errors);
+
+export function sanitizeErrorMessage(message: any) {
+  if (typeof message === "string" && errorValues.includes(message)) {
+    return message;
+  } else {
+    return "an unknown error has occurred";
+  }
+}
+
+export function mapErrorDetails(details: ValidationErrorItem[]) {
+  return details.map((item) => ({
+    message: item.message,
+    path: item.path,
+    type: item.type,
+  }));
+}

examples/basic-crud-application/server/package.json

@@ -0,0 +1,37 @@
+{
+  "name": "basic-crud-server",
+  "version": "0.0.1",
+  "description": "Server for the Basic CRUD Socket.IO example",
+  "main": "dist/lib/index.js",
+  "scripts": {
+    "start": "ts-node lib/index.ts",
+    "build": "tsc",
+    "test": "nyc mocha --require ts-node/register test/**/*.ts"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/socketio/socket.io.git"
+  },
+  "author": "Damien Arrachequesne <damien.arrachequesne@gmail.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/socketio/socket.io/issues"
+  },
+  "homepage": "https://github.com/socketio/socket.io#readme",
+  "dependencies": {
+    "joi": "^17.4.0",
+    "socket.io": "^4.0.1",
+    "uuid": "^8.3.2"
+  },
+  "devDependencies": {
+    "@types/chai": "^4.2.16",
+    "@types/mocha": "^10.0.0",
+    "@types/uuid": "^8.3.0",
+    "chai": "^4.3.4",
+    "mocha": "^10.0.0",
+    "nyc": "^15.1.0",
+    "socket.io-client": "^4.0.1",
+    "ts-node": "^10.9.1",
+    "typescript": "^4.2.4"
+  }
+}

examples/basic-crud-application/server/test/todo-management/todo.tests.ts

@@ -0,0 +1,309 @@
+import { createApplication } from "../../lib/app";
+import { createServer, Server } from "http";
+import {
+  InMemoryTodoRepository,
+  TodoRepository,
+} from "../../lib/todo-management/todo.repository";
+import { AddressInfo } from "net";
+import { io, Socket } from "socket.io-client";
+import { ClientEvents, ServerEvents } from "../../lib/events";
+import { expect } from "chai";
+
+const createPartialDone = (count: number, done: () => void) => {
+  let i = 0;
+  return () => {
+    if (++i === count) {
+      done();
+    }
+  };
+};
+
+describe("todo management", () => {
+  let httpServer: Server,
+    socket: Socket<ServerEvents, ClientEvents>,
+    otherSocket: Socket<ServerEvents, ClientEvents>,
+    todoRepository: TodoRepository;
+
+  beforeEach((done) => {
+    const partialDone = createPartialDone(2, done);
+
+    httpServer = createServer();
+    todoRepository = new InMemoryTodoRepository();
+
+    createApplication(httpServer, {
+      todoRepository,
+    });
+
+    httpServer.listen(() => {
+      const port = (httpServer.address() as AddressInfo).port;
+      socket = io(`http://localhost:${port}`);
+      socket.on("connect", partialDone);
+
+      otherSocket = io(`http://localhost:${port}`);
+      otherSocket.on("connect", partialDone);
+    });
+  });
+
+  afterEach(() => {
+    httpServer.close();
+    socket.disconnect();
+    otherSocket.disconnect();
+  });
+
+  describe("create todo", () => {
+    it("should create a todo entity", (done) => {
+      const partialDone = createPartialDone(2, done);
+
+      socket.emit(
+        "todo:create",
+        {
+          title: "lorem ipsum",
+          completed: false,
+        },
+        async (res) => {
+          if ("error" in res) {
+            return done(new Error("should not happen"));
+          }
+          expect(res.data).to.be.a("string");
+
+          const storedEntity = await todoRepository.findById(res.data);
+          expect(storedEntity).to.eql({
+            id: res.data,
+            title: "lorem ipsum",
+            completed: false,
+          });
+
+          partialDone();
+        }
+      );
+
+      otherSocket.on("todo:created", (todo) => {
+        expect(todo.id).to.be.a("string");
+        expect(todo.title).to.eql("lorem ipsum");
+        expect(todo.completed).to.eql(false);
+        partialDone();
+      });
+    });
+
+    it("should fail with an invalid entity", (done) => {
+      const incompleteTodo = {
+        completed: "false",
+        description: true,
+      };
+      // @ts-ignore
+      socket.emit("todo:create", incompleteTodo, (res) => {
+        if (!("error" in res)) {
+          return done(new Error("should not happen"));
+        }
+        expect(res.error).to.eql("invalid payload");
+        expect(res.errorDetails).to.eql([
+          {
+            message: '"title" is required',
+            path: ["title"],
+            type: "any.required",
+          },
+        ]);
+        done();
+      });
+
+      otherSocket.on("todo:created", () => {
+        done(new Error("should not happen"));
+      });
+    });
+  });
+
+  describe("read todo", () => {
+    it("should return a todo entity", (done) => {
+      todoRepository.save({
+        id: "254dbf85-f5b9-4675-b913-acab5d600884",
+        title: "lorem ipsum",
+        completed: true,
+      });
+
+      socket.emit(
+        "todo:read",
+        "254dbf85-f5b9-4675-b913-acab5d600884",
+        (res) => {
+          if ("error" in res) {
+            return done(new Error("should not happen"));
+          }
+          expect(res.data.id).to.eql("254dbf85-f5b9-4675-b913-acab5d600884");
+          expect(res.data.title).to.eql("lorem ipsum");
+          expect(res.data.completed).to.eql(true);
+          done();
+        }
+      );
+    });
+
+    it("should fail with an invalid ID", (done) => {
+      socket.emit("todo:read", "123", (res) => {
+        if ("error" in res) {
+          expect(res.error).to.eql("entity not found");
+          done();
+        } else {
+          done(new Error("should not happen"));
+        }
+      });
+    });
+
+    it("should fail with an unknown entity", (done) => {
+      socket.emit(
+        "todo:read",
+        "6edcf81e-7049-40e0-8497-9cdd52414f75",
+        (res) => {
+          if ("error" in res) {
+            expect(res.error).to.eql("entity not found");
+            done();
+          } else {
+            done(new Error("should not happen"));
+          }
+        }
+      );
+    });
+  });
+
+  describe("update todo", () => {
+    it("should update a todo entity", (done) => {
+      const partialDone = createPartialDone(2, done);
+
+      todoRepository.save({
+        id: "c7790b35-6bbb-45dd-8d67-a281ca407b43",
+        title: "lorem ipsum",
+        completed: true,
+      });
+
+      socket.emit(
+        "todo:update",
+        {
+          id: "c7790b35-6bbb-45dd-8d67-a281ca407b43",
+          title: "dolor sit amet",
+          completed: true,
+        },
+        async () => {
+          const storedEntity = await todoRepository.findById(
+            "c7790b35-6bbb-45dd-8d67-a281ca407b43"
+          );
+          expect(storedEntity).to.eql({
+            id: "c7790b35-6bbb-45dd-8d67-a281ca407b43",
+            title: "dolor sit amet",
+            completed: true,
+          });
+          partialDone();
+        }
+      );
+
+      otherSocket.on("todo:updated", (todo) => {
+        expect(todo.title).to.eql("dolor sit amet");
+        expect(todo.completed).to.eql(true);
+        partialDone();
+      });
+    });
+
+    it("should fail with an invalid entity", (done) => {
+      const incompleteTodo = {
+        id: "123",
+        completed: "false",
+        description: true,
+      };
+      // @ts-ignore
+      socket.emit("todo:update", incompleteTodo, (res) => {
+        if (!(res && "error" in res)) {
+          return done(new Error("should not happen"));
+        }
+        expect(res.error).to.eql("invalid payload");
+        expect(res.errorDetails).to.eql([
+          {
+            message: '"id" must be a valid GUID',
+            path: ["id"],
+            type: "string.guid",
+          },
+          {
+            message: '"title" is required',
+            path: ["title"],
+            type: "any.required",
+          },
+        ]);
+        done();
+      });
+
+      otherSocket.on("todo:updated", () => {
+        done(new Error("should not happen"));
+      });
+    });
+  });
+
+  describe("delete todo", () => {
+    it("should delete a todo entity", (done) => {
+      const partialDone = createPartialDone(2, done);
+      const id = "58960ab2-4e78-4ced-8079-134f12179d46";
+
+      todoRepository.save({
+        id,
+        title: "lorem ipsum",
+        completed: true,
+      });
+
+      socket.emit("todo:delete", id, async () => {
+        try {
+          await todoRepository.findById(id);
+        } catch (e) {
+          partialDone();
+        }
+      });
+
+      otherSocket.on("todo:deleted", (id) => {
+        expect(id).to.eql("58960ab2-4e78-4ced-8079-134f12179d46");
+        partialDone();
+      });
+    });
+
+    it("should fail with an invalid ID", (done) => {
+      socket.emit("todo:delete", "123", (res) => {
+        if (!(res && "error" in res)) {
+          return done(new Error("should not happen"));
+        }
+        expect(res.error).to.eql("entity not found");
+        done();
+      });
+
+      otherSocket.on("todo:deleted", () => {
+        done(new Error("should not happen"));
+      });
+    });
+  });
+
+  describe("list todo", () => {
+    it("should return a list of entities", (done) => {
+      todoRepository.save({
+        id: "d445db6d-9d55-4ff2-88ae-bd1f81c299d2",
+        title: "lorem ipsum",
+        completed: false,
+      });
+
+      todoRepository.save({
+        id: "5f56fb59-a887-4984-93bf-eb39b4170a35",
+        title: "dolor sit amet",
+        completed: true,
+      });
+
+      socket.emit("todo:list", (res) => {
+        if ("error" in res) {
+          return done(new Error("should not happen"));
+        }
+        expect(res.data).to.eql([
+          {
+            id: "d445db6d-9d55-4ff2-88ae-bd1f81c299d2",
+            title: "lorem ipsum",
+            completed: false,
+          },
+          {
+            id: "5f56fb59-a887-4984-93bf-eb39b4170a35",
+            title: "dolor sit amet",
+            completed: true,
+          },
+        ]);
+        done();
+      });
+    });
+  });
+});

examples/basic-crud-application/server/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "outDir": "./dist",
+    "module": "commonjs",
+    "target": "es2017",
+    "strict": true
+  },
+  "include": [
+    "./lib/**/*"
+  ]
+}

examples/basic-websocket-client/README.md

@@ -0,0 +1,18 @@
+# Basic Socket.IO client
+
+Please check the associated guide: https://socket.io/how-to/build-a-basic-client
+
+Content:
+
+```
+├── bundle
+│   └── socket.io.min.js
+├── src
+│   └── index.js
+├── test
+│   └── index.js
+├── check-bundle-size.js
+├── package.json
+├── README.md
+└── rollup.config.js
+```

examples/basic-websocket-client/bundle/socket.io.min.js

@@ -0,0 +1 @@
+class e{#e=new Map;on(e,t){let s=this.#e.get(e);s||this.#e.set(e,s=[]),s.push(t)}emit(e,...t){const s=this.#e.get(e);if(s)for(const e of s)e.apply(null,t)}}const t="0",s="1",n="2",i="3",o="4",r={CONNECT:0,DISCONNECT:1,EVENT:2};function c(){}class a extends e{id;connected=!1;#t;#s;#n;#i;#o;#r=[];#c;#a=!0;constructor(e,t){super(),this.#t=e,this.#s=Object.assign({path:"/socket.io/",reconnectionDelay:2e3},t),this.#h()}#h(){this.#n=new WebSocket(this.#u()),this.#n.onmessage=({data:e})=>this.#p(e),this.#n.onerror=c,this.#n.onclose=()=>this.#l("transport close")}#u(){return`${this.#t.replace(/^http/,"ws")}${this.#s.path}?EIO=4&transport=websocket`}#p(e){if("string"==typeof e)switch(e[0]){case t:this.#d(e);break;case s:this.#l("transport close");break;case n:this.#T(),this.#m(i);break;case o:let c;try{c=function(e){let t=1;const s={type:parseInt(e.charAt(t++),10)};e.charAt(t)&&(s.data=JSON.parse(e.substring(t)));if(!function(e){switch(e.type){case r.CONNECT:return"object"==typeof e.data;case r.DISCONNECT:return void 0===e.data;case r.EVENT:{const t=e.data;return Array.isArray(t)&&t.length>0&&"string"==typeof t[0]}default:return!1}}(s))throw new Error("invalid format");return s}(e)}catch(e){return this.#l("parse error")}this.#f(c);break;default:this.#l("parse error")}}#d(e){let t;try{t=JSON.parse(e.substring(1))}catch(e){return this.#l("parse error")}this.#o=t.pingInterval+t.pingTimeout,this.#T(),this.#C()}#f(e){switch(e.type){case r.CONNECT:this.#g(e);break;case r.DISCONNECT:this.#a=!1,this.#l("io server disconnect");break;case r.EVENT:super.emit.apply(this,e.data);break;default:this.#l("parse error")}}#g(e){this.id=e.data.sid,this.connected=!0,this.#r.forEach((e=>this.#y(e))),this.#r.slice(0),super.emit("connect")}#l(e){this.#n&&(this.#n.onclose=c,this.#n.close()),clearTimeout(this.#i),clearTimeout(this.#c),this.connected?(this.connected=!1,this.id=void 0,super.emit("disconnect",e)):super.emit("connect_error",e),this.#a&&(this.#c=setTimeout((()=>this.#h()),this.#s.reconnectionDelay))}#T(){clearTimeout(this.#i),this.#i=setTimeout((()=>{this.#l("ping timeout")}),this.#o)}#m(e){this.#n.readyState===WebSocket.OPEN&&this.#n.send(e)}#y(e){this.#m(o+function(e){let t=""+e.type;e.data&&(t+=JSON.stringify(e.data));return t}(e))}#C(){this.#y({type:r.CONNECT})}emit(...e){const t={type:r.EVENT,data:e};this.connected?this.#y(t):this.#r.push(t)}disconnect(){this.#a=!1,this.#l("io client disconnect")}}function h(e,t){return"string"!=typeof e&&(t=e,e=location.origin),new a(e,t)}export{h as io};

examples/basic-websocket-client/check-bundle-size.js

@@ -0,0 +1,17 @@
+import { rollup } from "rollup";
+import terser from "@rollup/plugin-terser";
+import { brotliCompressSync } from "node:zlib";
+
+const rollupBuild = await rollup({
+  input: "./src/index.js"
+});
+
+const rollupOutput = await rollupBuild.generate({
+  format: "esm",
+  plugins: [terser()],
+});
+
+const bundleAsString = rollupOutput.output[0].code;
+const brotliedBundle = brotliCompressSync(Buffer.from(bundleAsString));
+
+console.log(`Bundle size: ${brotliedBundle.length} B`);

examples/basic-websocket-client/package.json

@@ -0,0 +1,18 @@
+{
+  "type": "module",
+  "devDependencies": {
+    "@rollup/plugin-terser": "^0.4.0",
+    "chai": "^4.3.7",
+    "mocha": "^10.2.0",
+    "prettier": "^2.8.4",
+    "rollup": "^3.20.2",
+    "socket.io": "^4.6.1",
+    "ws": "^8.13.0"
+  },
+  "scripts": {
+    "bundle": "rollup -c",
+    "check-bundle-size": "node check-bundle-size.js",
+    "format": "prettier -w src/ test/",
+    "test": "mocha"
+  }
+}

examples/basic-websocket-client/rollup.config.js

@@ -0,0 +1,10 @@
+import terser from "@rollup/plugin-terser";
+
+export default {
+  input: "./src/index.js",
+  output: {
+    file: "./bundle/socket.io.min.js",
+    format: "esm",
+    plugins: [terser()],
+  }
+};

examples/basic-websocket-client/src/index.js

@@ -0,0 +1,273 @@
+class EventEmitter {
+  #listeners = new Map();
+
+  on(event, listener) {
+    let listeners = this.#listeners.get(event);
+    if (!listeners) {
+      this.#listeners.set(event, (listeners = []));
+    }
+    listeners.push(listener);
+  }
+
+  emit(event, ...args) {
+    const listeners = this.#listeners.get(event);
+    if (listeners) {
+      for (const listener of listeners) {
+        listener.apply(null, args);
+      }
+    }
+  }
+}
+
+const EIOPacketType = {
+  OPEN: "0",
+  CLOSE: "1",
+  PING: "2",
+  PONG: "3",
+  MESSAGE: "4",
+};
+
+const SIOPacketType = {
+  CONNECT: 0,
+  DISCONNECT: 1,
+  EVENT: 2,
+};
+
+function noop() {}
+
+class Socket extends EventEmitter {
+  id;
+  connected = false;
+
+  #uri;
+  #opts;
+  #ws;
+  #pingTimeoutTimer;
+  #pingTimeoutDelay;
+  #sendBuffer = [];
+  #reconnectTimer;
+  #shouldReconnect = true;
+
+  constructor(uri, opts) {
+    super();
+    this.#uri = uri;
+    this.#opts = Object.assign(
+      {
+        path: "/socket.io/",
+        reconnectionDelay: 2000,
+      },
+      opts
+    );
+    this.#open();
+  }
+
+  #open() {
+    this.#ws = new WebSocket(this.#createUrl());
+    this.#ws.onmessage = ({ data }) => this.#onMessage(data);
+    // dummy handler for Node.js
+    this.#ws.onerror = noop;
+    this.#ws.onclose = () => this.#onClose("transport close");
+  }
+
+  #createUrl() {
+    const uri = this.#uri.replace(/^http/, "ws");
+    const queryParams = "?EIO=4&transport=websocket";
+    return `${uri}${this.#opts.path}${queryParams}`;
+  }
+
+  #onMessage(data) {
+    if (typeof data !== "string") {
+      // TODO handle binary payloads
+      return;
+    }
+
+    switch (data[0]) {
+      case EIOPacketType.OPEN:
+        this.#onOpen(data);
+        break;
+
+      case EIOPacketType.CLOSE:
+        this.#onClose("transport close");
+        break;
+
+      case EIOPacketType.PING:
+        this.#resetPingTimeout();
+        this.#send(EIOPacketType.PONG);
+        break;
+
+      case EIOPacketType.MESSAGE:
+        let packet;
+        try {
+          packet = decode(data);
+        } catch (e) {
+          return this.#onClose("parse error");
+        }
+        this.#onPacket(packet);
+        break;
+
+      default:
+        this.#onClose("parse error");
+        break;
+    }
+  }
+
+  #onOpen(data) {
+    let handshake;
+    try {
+      handshake = JSON.parse(data.substring(1));
+    } catch (e) {
+      return this.#onClose("parse error");
+    }
+    this.#pingTimeoutDelay = handshake.pingInterval + handshake.pingTimeout;
+    this.#resetPingTimeout();
+    this.#doConnect();
+  }
+
+  #onPacket(packet) {
+    switch (packet.type) {
+      case SIOPacketType.CONNECT:
+        this.#onConnect(packet);
+        break;
+
+      case SIOPacketType.DISCONNECT:
+        this.#shouldReconnect = false;
+        this.#onClose("io server disconnect");
+        break;
+
+      case SIOPacketType.EVENT:
+        super.emit.apply(this, packet.data);
+        break;
+
+      default:
+        this.#onClose("parse error");
+        break;
+    }
+  }
+
+  #onConnect(packet) {
+    this.id = packet.data.sid;
+    this.connected = true;
+
+    this.#sendBuffer.forEach((packet) => this.#sendPacket(packet));
+    this.#sendBuffer.slice(0);
+
+    super.emit("connect");
+  }
+
+  #onClose(reason) {
+    if (this.#ws) {
+      this.#ws.onclose = noop;
+      this.#ws.close();
+    }
+
+    clearTimeout(this.#pingTimeoutTimer);
+    clearTimeout(this.#reconnectTimer);
+
+    if (this.connected) {
+      this.connected = false;
+      this.id = undefined;
+      super.emit("disconnect", reason);
+    } else {
+      super.emit("connect_error", reason);
+    }
+
+    if (this.#shouldReconnect) {
+      this.#reconnectTimer = setTimeout(
+        () => this.#open(),
+        this.#opts.reconnectionDelay
+      );
+    }
+  }
+
+  #resetPingTimeout() {
+    clearTimeout(this.#pingTimeoutTimer);
+    this.#pingTimeoutTimer = setTimeout(() => {
+      this.#onClose("ping timeout");
+    }, this.#pingTimeoutDelay);
+  }
+
+  #send(data) {
+    if (this.#ws.readyState === WebSocket.OPEN) {
+      this.#ws.send(data);
+    }
+  }
+
+  #sendPacket(packet) {
+    this.#send(EIOPacketType.MESSAGE + encode(packet));
+  }
+
+  #doConnect() {
+    this.#sendPacket({ type: SIOPacketType.CONNECT });
+  }
+
+  emit(...args) {
+    const packet = {
+      type: SIOPacketType.EVENT,
+      data: args,
+    };
+
+    if (this.connected) {
+      this.#sendPacket(packet);
+    } else {
+      this.#sendBuffer.push(packet);
+    }
+  }
+
+  disconnect() {
+    this.#shouldReconnect = false;
+    this.#onClose("io client disconnect");
+  }
+}
+
+function encode(packet) {
+  let output = "" + packet.type;
+
+  if (packet.data) {
+    output += JSON.stringify(packet.data);
+  }
+
+  return output;
+}
+
+function decode(data) {
+  let i = 1; // skip "4" prefix
+
+  const packet = {
+    type: parseInt(data.charAt(i++), 10),
+  };
+
+  if (data.charAt(i)) {
+    packet.data = JSON.parse(data.substring(i));
+  }
+
+  if (!isPacketValid(packet)) {
+    throw new Error("invalid format");
+  }
+
+  return packet;
+}
+
+function isPacketValid(packet) {
+  switch (packet.type) {
+    case SIOPacketType.CONNECT:
+      return typeof packet.data === "object";
+    case SIOPacketType.DISCONNECT:
+      return packet.data === undefined;
+    case SIOPacketType.EVENT: {
+      const args = packet.data;
+      return (
+        Array.isArray(args) && args.length > 0 && typeof args[0] === "string"
+      );
+    }
+    default:
+      return false;
+  }
+}
+
+export function io(uri, opts) {
+  if (typeof uri !== "string") {
+    opts = uri;
+    uri = location.origin;
+  }
+  return new Socket(uri, opts);
+}

examples/basic-websocket-client/test/index.js

@@ -0,0 +1,162 @@
+import { createServer } from "node:http";
+import { io as ioc } from "../src/index.js";
+import { WebSocket } from "ws";
+import { Server } from "socket.io";
+import { expect } from "chai";
+
+// @ts-ignore for Node.js
+globalThis.WebSocket = WebSocket;
+
+function waitFor(emitter, eventName) {
+  return new Promise((resolve) => {
+    emitter.on(eventName, resolve);
+  });
+}
+
+function sleep(delay) {
+  return new Promise((resolve) => {
+    setTimeout(resolve, delay);
+  });
+}
+
+describe("basic client", () => {
+  let io, port, socket;
+
+  beforeEach(() => {
+    const httpServer = createServer();
+    io = new Server(httpServer);
+
+    httpServer.listen(0);
+    port = httpServer.address().port;
+  });
+
+  afterEach(() => {
+    io.close();
+    socket.disconnect();
+  });
+
+  it("should connect", async () => {
+    socket = ioc(`ws://localhost:${port}`);
+
+    await waitFor(socket, "connect");
+
+    expect(socket.connected).to.eql(true);
+    expect(socket.id).to.be.a("string");
+  });
+
+  it("should connect with 'http://' scheme", async () => {
+    socket = ioc(`http://localhost:${port}`);
+
+    await waitFor(socket, "connect");
+  });
+
+  it("should connect with URL inferred from 'window.location'", async () => {
+    globalThis.location = {
+      origin: `http://localhost:${port}`,
+    };
+    socket = ioc();
+
+    await waitFor(socket, "connect");
+  });
+
+  it("should fail to connect to an invalid URL", async () => {
+    socket = ioc(`http://localhost:4321`);
+
+    await waitFor(socket, "connect_error");
+  });
+
+  it("should receive an event", async () => {
+    io.on("connection", (socket) => {
+      socket.emit("foo", 123);
+    });
+
+    socket = ioc(`ws://localhost:${port}`);
+
+    const value = await waitFor(socket, "foo");
+
+    expect(value).to.eql(123);
+  });
+
+  it("should send an event (not buffered)", async () => {
+    socket = ioc(`ws://localhost:${port}`);
+
+    const [serverSocket] = await Promise.all([
+      waitFor(io, "connection"),
+      waitFor(socket, "connect"),
+    ]);
+
+    socket.emit("foo", 456);
+
+    const value = await waitFor(serverSocket, "foo");
+
+    expect(value).to.eql(456);
+  });
+
+  it("should send an event (buffered)", async () => {
+    socket = ioc(`ws://localhost:${port}`);
+
+    socket.emit("foo", 789);
+
+    const [serverSocket] = await Promise.all([
+      waitFor(io, "connection"),
+      waitFor(socket, "connect"),
+    ]);
+
+    const value = await waitFor(serverSocket, "foo");
+
+    expect(value).to.eql(789);
+  });
+
+  it("should reconnect", async () => {
+    socket = ioc(`ws://localhost:${port}`, {
+      reconnectionDelay: 50,
+    });
+
+    await waitFor(socket, "connect");
+
+    io.close();
+
+    await waitFor(socket, "disconnect");
+
+    io.listen(port);
+
+    await waitFor(socket, "connect");
+  });
+
+  it("should respond to PING packets", async () => {
+    io.engine.opts.pingInterval = 50;
+    io.engine.opts.pingTimeout = 20;
+
+    socket = ioc(`ws://localhost:${port}`);
+
+    await waitFor(socket, "connect");
+
+    await sleep(500);
+
+    expect(socket.connected).to.eql(true);
+  });
+
+  it("should disconnect (client side)", async () => {
+    socket = ioc(`ws://localhost:${port}`);
+
+    await waitFor(socket, "connect");
+
+    socket.disconnect();
+
+    expect(socket.connected).to.eql(false);
+    expect(socket.id).to.eql(undefined);
+  });
+
+  it("should disconnect (server side)", async () => {
+    socket = ioc(`ws://localhost:${port}`);
+
+    const [serverSocket] = await Promise.all([
+      waitFor(io, "connection"),
+      waitFor(socket, "connect"),
+    ]);
+
+    serverSocket.disconnect();
+
+    await waitFor(socket, "disconnect");
+  });
+});

examples/chat/README.md

@@ -6,7 +6,7 @@ A simple chat demo for Socket.IO
 ## How to use
 
 ```
-$ npm ci
+$ npm i
 $ npm start
 ```
 

examples/chat/package-lock.json

@@ -1,499 +0,0 @@
-{
-  "name": "socket.io-chat",
-  "version": "0.0.0",
-  "lockfileVersion": 1,
-  "requires": true,
-  "dependencies": {
-    "accepts": {
-      "version": "1.3.7",
-      "resolved": "https://registry.npmjs.org/accepts/-/accepts-1.3.7.tgz",
-      "integrity": "sha512-Il80Qs2WjYlJIBNzNkK6KYqlVMTbZLXgHx2oT0pU/fjRHyEp+PEfEPY0R3WCwAGVOtauxh1hOxNgIf5bv7dQpA==",
-      "requires": {
-        "mime-types": "~2.1.24",
-        "negotiator": "0.6.2"
-      }
-    },
-    "array-flatten": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
-      "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI="
-    },
-    "base64id": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/base64id/-/base64id-2.0.0.tgz",
-      "integrity": "sha512-lGe34o6EHj9y3Kts9R4ZYs/Gr+6N7MCaMlIFA3F1R2O5/m7K06AxfSeO5530PEERE6/WyEg3lsuyw4GHlPZHog=="
-    },
-    "body-parser": {
-      "version": "1.19.0",
-      "resolved": "https://registry.npmjs.org/body-parser/-/body-parser-1.19.0.tgz",
-      "integrity": "sha512-dhEPs72UPbDnAQJ9ZKMNTP6ptJaionhP5cBb541nXPlW60Jepo9RV/a4fX4XWW9CuFNK22krhrj1+rgzifNCsw==",
-      "requires": {
-        "bytes": "3.1.0",
-        "content-type": "~1.0.4",
-        "debug": "2.6.9",
-        "depd": "~1.1.2",
-        "http-errors": "1.7.2",
-        "iconv-lite": "0.4.24",
-        "on-finished": "~2.3.0",
-        "qs": "6.7.0",
-        "raw-body": "2.4.0",
-        "type-is": "~1.6.17"
-      }
-    },
-    "bytes": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.1.0.tgz",
-      "integrity": "sha512-zauLjrfCG+xvoyaqLoV8bLVXXNGC4JqlxFCutSDWA6fJrTo2ZuvLYTqZ7aHBLZSMOopbzwv8f+wZcVzfVTI2Dg=="
-    },
-    "component-emitter": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.3.0.tgz",
-      "integrity": "sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg=="
-    },
-    "content-disposition": {
-      "version": "0.5.3",
-      "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-0.5.3.tgz",
-      "integrity": "sha512-ExO0774ikEObIAEV9kDo50o+79VCUdEB6n6lzKgGwupcVeRlhrj3qGAfwq8G6uBJjkqLrhT0qEYFcWng8z1z0g==",
-      "requires": {
-        "safe-buffer": "5.1.2"
-      }
-    },
-    "content-type": {
-      "version": "1.0.4",
-      "resolved": "https://registry.npmjs.org/content-type/-/content-type-1.0.4.tgz",
-      "integrity": "sha512-hIP3EEPs8tB9AT1L+NUqtwOAps4mk2Zob89MWXMHjHWg9milF/j4osnnQLXBCBFBk/tvIG/tUc9mOUJiPBhPXA=="
-    },
-    "cookie": {
-      "version": "0.4.0",
-      "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.4.0.tgz",
-      "integrity": "sha512-+Hp8fLp57wnUSt0tY0tHEXh4voZRDnoIrZPqlo3DPiI4y9lwg/jqx+1Om94/W6ZaPDOUbnjOt/99w66zk+l1Xg=="
-    },
-    "cookie-signature": {
-      "version": "1.0.6",
-      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
-      "integrity": "sha1-4wOogrNCzD7oylE6eZmXNNqzriw="
-    },
-    "cors": {
-      "version": "2.8.5",
-      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
-      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
-      "requires": {
-        "object-assign": "^4",
-        "vary": "^1"
-      }
-    },
-    "debug": {
-      "version": "2.6.9",
-      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
-      "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
-      "requires": {
-        "ms": "2.0.0"
-      }
-    },
-    "depd": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/depd/-/depd-1.1.2.tgz",
-      "integrity": "sha1-m81S4UwJd2PnSbJ0xDRu0uVgtak="
-    },
-    "destroy": {
-      "version": "1.0.4",
-      "resolved": "https://registry.npmjs.org/destroy/-/destroy-1.0.4.tgz",
-      "integrity": "sha1-l4hXRCxEdJ5CBmE+N5RiBYJqvYA="
-    },
-    "ee-first": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
-      "integrity": "sha1-WQxhFWsK4vTwJVcyoViyZrxWsh0="
-    },
-    "encodeurl": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/encodeurl/-/encodeurl-1.0.2.tgz",
-      "integrity": "sha1-rT/0yG7C0CkyL1oCw6mmBslbP1k="
-    },
-    "engine.io": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-4.0.1.tgz",
-      "integrity": "sha512-6EaSBxasBUwxRdf6B68SEYpD3tcrG80J4YTzHl/D+9Q+vM0AMHZabfYcc2WdnvEaQxZjX/UZsa+UdGoM0qQQkQ==",
-      "requires": {
-        "accepts": "~1.3.4",
-        "base64id": "2.0.0",
-        "cookie": "~0.4.1",
-        "cors": "~2.8.5",
-        "debug": "~4.1.0",
-        "engine.io-parser": "~4.0.0",
-        "ws": "^7.1.2"
-      },
-      "dependencies": {
-        "cookie": {
-          "version": "0.4.1",
-          "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.4.1.tgz",
-          "integrity": "sha512-ZwrFkGJxUR3EIoXtO+yVE69Eb7KlixbaeAWfBQB9vVsNn/o+Yw69gBWSSDK825hQNdN+wF8zELf3dFNl/kxkUA=="
-        },
-        "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
-          "requires": {
-            "ms": "^2.1.1"
-          }
-        },
-        "ms": {
-          "version": "2.1.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
-        }
-      }
-    },
-    "engine.io-parser": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-4.0.1.tgz",
-      "integrity": "sha512-v5aZK1hlckcJDGmHz3W8xvI3NUHYc9t8QtTbqdR5OaH3S9iJZilPubauOm+vLWOMMWzpE3hiq92l9lTAHamRCg=="
-    },
-    "escape-html": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/escape-html/-/escape-html-1.0.3.tgz",
-      "integrity": "sha1-Aljq5NPQwJdN4cFpGI7wBR0dGYg="
-    },
-    "etag": {
-      "version": "1.8.1",
-      "resolved": "https://registry.npmjs.org/etag/-/etag-1.8.1.tgz",
-      "integrity": "sha1-Qa4u62XvpiJorr/qg6x9eSmbCIc="
-    },
-    "express": {
-      "version": "4.17.1",
-      "resolved": "https://registry.npmjs.org/express/-/express-4.17.1.tgz",
-      "integrity": "sha512-mHJ9O79RqluphRrcw2X/GTh3k9tVv8YcoyY4Kkh4WDMUYKRZUq0h1o0w2rrrxBqM7VoeUVqgb27xlEMXTnYt4g==",
-      "requires": {
-        "accepts": "~1.3.7",
-        "array-flatten": "1.1.1",
-        "body-parser": "1.19.0",
-        "content-disposition": "0.5.3",
-        "content-type": "~1.0.4",
-        "cookie": "0.4.0",
-        "cookie-signature": "1.0.6",
-        "debug": "2.6.9",
-        "depd": "~1.1.2",
-        "encodeurl": "~1.0.2",
-        "escape-html": "~1.0.3",
-        "etag": "~1.8.1",
-        "finalhandler": "~1.1.2",
-        "fresh": "0.5.2",
-        "merge-descriptors": "1.0.1",
-        "methods": "~1.1.2",
-        "on-finished": "~2.3.0",
-        "parseurl": "~1.3.3",
-        "path-to-regexp": "0.1.7",
-        "proxy-addr": "~2.0.5",
-        "qs": "6.7.0",
-        "range-parser": "~1.2.1",
-        "safe-buffer": "5.1.2",
-        "send": "0.17.1",
-        "serve-static": "1.14.1",
-        "setprototypeof": "1.1.1",
-        "statuses": "~1.5.0",
-        "type-is": "~1.6.18",
-        "utils-merge": "1.0.1",
-        "vary": "~1.1.2"
-      }
-    },
-    "finalhandler": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/finalhandler/-/finalhandler-1.1.2.tgz",
-      "integrity": "sha512-aAWcW57uxVNrQZqFXjITpW3sIUQmHGG3qSb9mUah9MgMC4NeWhNOlNjXEYq3HjRAvL6arUviZGGJsBg6z0zsWA==",
-      "requires": {
-        "debug": "2.6.9",
-        "encodeurl": "~1.0.2",
-        "escape-html": "~1.0.3",
-        "on-finished": "~2.3.0",
-        "parseurl": "~1.3.3",
-        "statuses": "~1.5.0",
-        "unpipe": "~1.0.0"
-      }
-    },
-    "forwarded": {
-      "version": "0.1.2",
-      "resolved": "https://registry.npmjs.org/forwarded/-/forwarded-0.1.2.tgz",
-      "integrity": "sha1-mMI9qxF1ZXuMBXPozszZGw/xjIQ="
-    },
-    "fresh": {
-      "version": "0.5.2",
-      "resolved": "https://registry.npmjs.org/fresh/-/fresh-0.5.2.tgz",
-      "integrity": "sha1-PYyt2Q2XZWn6g1qx+OSyOhBWBac="
-    },
-    "http-errors": {
-      "version": "1.7.2",
-      "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-1.7.2.tgz",
-      "integrity": "sha512-uUQBt3H/cSIVfch6i1EuPNy/YsRSOUBXTVfZ+yR7Zjez3qjBz6i9+i4zjNaoqcoFVI4lQJ5plg63TvGfRSDCRg==",
-      "requires": {
-        "depd": "~1.1.2",
-        "inherits": "2.0.3",
-        "setprototypeof": "1.1.1",
-        "statuses": ">= 1.5.0 < 2",
-        "toidentifier": "1.0.0"
-      }
-    },
-    "iconv-lite": {
-      "version": "0.4.24",
-      "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.24.tgz",
-      "integrity": "sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==",
-      "requires": {
-        "safer-buffer": ">= 2.1.2 < 3"
-      }
-    },
-    "inherits": {
-      "version": "2.0.3",
-      "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.3.tgz",
-      "integrity": "sha1-Yzwsg+PaQqUC9SRmAiSA9CCCYd4="
-    },
-    "ipaddr.js": {
-      "version": "1.9.1",
-      "resolved": "https://registry.npmjs.org/ipaddr.js/-/ipaddr.js-1.9.1.tgz",
-      "integrity": "sha512-0KI/607xoxSToH7GjN1FfSbLoU0+btTicjsQSWQlh/hZykN8KpmMf7uYwPW3R+akZ6R/w18ZlXSHBYXiYUPO3g=="
-    },
-    "media-typer": {
-      "version": "0.3.0",
-      "resolved": "https://registry.npmjs.org/media-typer/-/media-typer-0.3.0.tgz",
-      "integrity": "sha1-hxDXrwqmJvj/+hzgAWhUUmMlV0g="
-    },
-    "merge-descriptors": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/merge-descriptors/-/merge-descriptors-1.0.1.tgz",
-      "integrity": "sha1-sAqqVW3YtEVoFQ7J0blT8/kMu2E="
-    },
-    "methods": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/methods/-/methods-1.1.2.tgz",
-      "integrity": "sha1-VSmk1nZUE07cxSZmVoNbD4Ua/O4="
-    },
-    "mime": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/mime/-/mime-1.6.0.tgz",
-      "integrity": "sha512-x0Vn8spI+wuJ1O6S7gnbaQg8Pxh4NNHb7KSINmEWKiPE4RKOplvijn+NkmYmmRgP68mc70j2EbeTFRsrswaQeg=="
-    },
-    "mime-db": {
-      "version": "1.43.0",
-      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.43.0.tgz",
-      "integrity": "sha512-+5dsGEEovYbT8UY9yD7eE4XTc4UwJ1jBYlgaQQF38ENsKR3wj/8q8RFZrF9WIZpB2V1ArTVFUva8sAul1NzRzQ=="
-    },
-    "mime-types": {
-      "version": "2.1.26",
-      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.26.tgz",
-      "integrity": "sha512-01paPWYgLrkqAyrlDorC1uDwl2p3qZT7yl806vW7DvDoxwXi46jsjFbg+WdwotBIk6/MbEhO/dh5aZ5sNj/dWQ==",
-      "requires": {
-        "mime-db": "1.43.0"
-      }
-    },
-    "ms": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
-      "integrity": "sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g="
-    },
-    "negotiator": {
-      "version": "0.6.2",
-      "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-0.6.2.tgz",
-      "integrity": "sha512-hZXc7K2e+PgeI1eDBe/10Ard4ekbfrrqG8Ep+8Jmf4JID2bNg7NvCPOZN+kfF574pFQI7mum2AUqDidoKqcTOw=="
-    },
-    "object-assign": {
-      "version": "4.1.1",
-      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
-      "integrity": "sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM="
-    },
-    "on-finished": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/on-finished/-/on-finished-2.3.0.tgz",
-      "integrity": "sha1-IPEzZIGwg811M3mSoWlxqi2QaUc=",
-      "requires": {
-        "ee-first": "1.1.1"
-      }
-    },
-    "parseurl": {
-      "version": "1.3.3",
-      "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",
-      "integrity": "sha512-CiyeOxFT/JZyN5m0z9PfXw4SCBJ6Sygz1Dpl0wqjlhDEGGBP1GnsUVEL0p63hoG1fcj3fHynXi9NYO4nWOL+qQ=="
-    },
-    "path-to-regexp": {
-      "version": "0.1.7",
-      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-0.1.7.tgz",
-      "integrity": "sha1-32BBeABfUi8V60SQ5yR6G/qmf4w="
-    },
-    "proxy-addr": {
-      "version": "2.0.6",
-      "resolved": "https://registry.npmjs.org/proxy-addr/-/proxy-addr-2.0.6.tgz",
-      "integrity": "sha512-dh/frvCBVmSsDYzw6n926jv974gddhkFPfiN8hPOi30Wax25QZyZEGveluCgliBnqmuM+UJmBErbAUFIoDbjOw==",
-      "requires": {
-        "forwarded": "~0.1.2",
-        "ipaddr.js": "1.9.1"
-      }
-    },
-    "qs": {
-      "version": "6.7.0",
-      "resolved": "https://registry.npmjs.org/qs/-/qs-6.7.0.tgz",
-      "integrity": "sha512-VCdBRNFTX1fyE7Nb6FYoURo/SPe62QCaAyzJvUjwRaIsc+NePBEniHlvxFmmX56+HZphIGtV0XeCirBtpDrTyQ=="
-    },
-    "range-parser": {
-      "version": "1.2.1",
-      "resolved": "https://registry.npmjs.org/range-parser/-/range-parser-1.2.1.tgz",
-      "integrity": "sha512-Hrgsx+orqoygnmhFbKaHE6c296J+HTAQXoxEF6gNupROmmGJRoyzfG3ccAveqCBrwr/2yxQ5BVd/GTl5agOwSg=="
-    },
-    "raw-body": {
-      "version": "2.4.0",
-      "resolved": "https://registry.npmjs.org/raw-body/-/raw-body-2.4.0.tgz",
-      "integrity": "sha512-4Oz8DUIwdvoa5qMJelxipzi/iJIi40O5cGV1wNYp5hvZP8ZN0T+jiNkL0QepXs+EsQ9XJ8ipEDoiH70ySUJP3Q==",
-      "requires": {
-        "bytes": "3.1.0",
-        "http-errors": "1.7.2",
-        "iconv-lite": "0.4.24",
-        "unpipe": "1.0.0"
-      }
-    },
-    "safe-buffer": {
-      "version": "5.1.2",
-      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.1.2.tgz",
-      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g=="
-    },
-    "safer-buffer": {
-      "version": "2.1.2",
-      "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
-      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
-    },
-    "send": {
-      "version": "0.17.1",
-      "resolved": "https://registry.npmjs.org/send/-/send-0.17.1.tgz",
-      "integrity": "sha512-BsVKsiGcQMFwT8UxypobUKyv7irCNRHk1T0G680vk88yf6LBByGcZJOTJCrTP2xVN6yI+XjPJcNuE3V4fT9sAg==",
-      "requires": {
-        "debug": "2.6.9",
-        "depd": "~1.1.2",
-        "destroy": "~1.0.4",
-        "encodeurl": "~1.0.2",
-        "escape-html": "~1.0.3",
-        "etag": "~1.8.1",
-        "fresh": "0.5.2",
-        "http-errors": "~1.7.2",
-        "mime": "1.6.0",
-        "ms": "2.1.1",
-        "on-finished": "~2.3.0",
-        "range-parser": "~1.2.1",
-        "statuses": "~1.5.0"
-      },
-      "dependencies": {
-        "ms": {
-          "version": "2.1.1",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.1.tgz",
-          "integrity": "sha512-tgp+dl5cGk28utYktBsrFqA7HKgrhgPsg6Z/EfhWI4gl1Hwq8B/GmY/0oXZ6nF8hDVesS/FpnYaD/kOWhYQvyg=="
-        }
-      }
-    },
-    "serve-static": {
-      "version": "1.14.1",
-      "resolved": "https://registry.npmjs.org/serve-static/-/serve-static-1.14.1.tgz",
-      "integrity": "sha512-JMrvUwE54emCYWlTI+hGrGv5I8dEwmco/00EvkzIIsR7MqrHonbD9pO2MOfFnpFntl7ecpZs+3mW+XbQZu9QCg==",
-      "requires": {
-        "encodeurl": "~1.0.2",
-        "escape-html": "~1.0.3",
-        "parseurl": "~1.3.3",
-        "send": "0.17.1"
-      }
-    },
-    "setprototypeof": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.1.1.tgz",
-      "integrity": "sha512-JvdAWfbXeIGaZ9cILp38HntZSFSo3mWg6xGcJJsd+d4aRMOqauag1C63dJfDw7OaMYwEbHMOxEZ1lqVRYP2OAw=="
-    },
-    "socket.io": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-3.0.0.tgz",
-      "integrity": "sha512-arLQtd+UoJ08NXBRBGUJDyQ9B+cc9WwD67hc5s1WQcs2DyAkYzI5HWg4U0CrFtK00kjyAWxBGhLwVbfOeMqz1A==",
-      "requires": {
-        "accepts": "~1.3.4",
-        "base64id": "~2.0.0",
-        "debug": "~4.1.0",
-        "engine.io": "~4.0.0",
-        "socket.io-adapter": "~2.0.3",
-        "socket.io-parser": "~4.0.1"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
-          "requires": {
-            "ms": "^2.1.1"
-          }
-        },
-        "ms": {
-          "version": "2.1.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
-        }
-      }
-    },
-    "socket.io-adapter": {
-      "version": "2.0.3",
-      "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-2.0.3.tgz",
-      "integrity": "sha512-2wo4EXgxOGSFueqvHAdnmi5JLZzWqMArjuP4nqC26AtLh5PoCPsaRbRdah2xhcwTAMooZfjYiNVNkkmmSMaxOQ=="
-    },
-    "socket.io-parser": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-4.0.1.tgz",
-      "integrity": "sha512-5JfNykYptCwU2lkOI0ieoePWm+6stEhkZ2UnLDjqnE1YEjUlXXLd1lpxPZ+g+h3rtaytwWkWrLQCaJULlGqjOg==",
-      "requires": {
-        "component-emitter": "~1.3.0",
-        "debug": "~4.1.0"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
-          "requires": {
-            "ms": "^2.1.1"
-          }
-        },
-        "ms": {
-          "version": "2.1.2",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
-        }
-      }
-    },
-    "statuses": {
-      "version": "1.5.0",
-      "resolved": "https://registry.npmjs.org/statuses/-/statuses-1.5.0.tgz",
-      "integrity": "sha1-Fhx9rBd2Wf2YEfQ3cfqZOBR4Yow="
-    },
-    "toidentifier": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/toidentifier/-/toidentifier-1.0.0.tgz",
-      "integrity": "sha512-yaOH/Pk/VEhBWWTlhI+qXxDFXlejDGcQipMlyxda9nthulaxLZUNcUqFxokp0vcYnvteJln5FNQDRrxj3YcbVw=="
-    },
-    "type-is": {
-      "version": "1.6.18",
-      "resolved": "https://registry.npmjs.org/type-is/-/type-is-1.6.18.tgz",
-      "integrity": "sha512-TkRKr9sUTxEH8MdfuCSP7VizJyzRNMjj2J2do2Jr3Kym598JVdEksuzPQCnlFPW4ky9Q+iA+ma9BGm06XQBy8g==",
-      "requires": {
-        "media-typer": "0.3.0",
-        "mime-types": "~2.1.24"
-      }
-    },
-    "unpipe": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/unpipe/-/unpipe-1.0.0.tgz",
-      "integrity": "sha1-sr9O6FFKrmFltIF4KdIbLvSZBOw="
-    },
-    "utils-merge": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/utils-merge/-/utils-merge-1.0.1.tgz",
-      "integrity": "sha1-n5VxD1CiZ5R7LMwSR0HBAoQn5xM="
-    },
-    "vary": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
-      "integrity": "sha1-IpnwLG3tMNSllhsLn3RSShj2NPw="
-    },
-    "ws": {
-      "version": "7.4.0",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-7.4.0.tgz",
-      "integrity": "sha512-kyFwXuV/5ymf+IXhS6f0+eAFvydbaBW3zjpT6hUdAh/hbVjTIB5EHBGi0bPoCLSK2wcuz3BrEkB9LrYv1Nm4NQ=="
-    }
-  }
-}

examples/chat/package.json

@@ -8,7 +8,7 @@
   "license": "BSD",
   "dependencies": {
     "express": "~4.17.1",
-    "socket.io": "^3.0.0"
+    "socket.io": "^4.0.0"
   },
   "scripts": {
     "start": "node index.js"

examples/chat/public/main.js

@@ -72,7 +72,7 @@ $(function() {
   }
 
   // Adds the visual chat message to the message list
-  const addChatMessage = (data, options) => {
+  const addChatMessage = (data, options = {}) => {
     // Don't fade the message in if there is an 'X was typing'
     const $typingMessages = getTypingMessages(data);
     if ($typingMessages.length !== 0) {
@@ -264,14 +264,14 @@ $(function() {
     log('you have been disconnected');
   });
 
-  socket.on('reconnect', () => {
+  socket.io.on('reconnect', () => {
     log('you have been reconnected');
     if (username) {
       socket.emit('add user', username);
     }
   });
 
-  socket.on('reconnect_error', () => {
+  socket.io.on('reconnect_error', () => {
     log('attempt to reconnect has failed');
   });
 

examples/cluster-haproxy/docker-compose.yml

@@ -1,51 +1,53 @@
+services:
+  haproxy:
+    image: haproxy:1.7-alpine
+    volumes:
+      - ./haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
+    links:
+      - server-john
+      - server-paul
+      - server-george
+      - server-ringo
+    ports:
+     - "3000:80"
 
-haproxy:
-  build: ./haproxy
-  links:
-    - server-john
-    - server-paul
-    - server-george
-    - server-ringo
-  ports:
-   - "3000:80"
+  server-john:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=John
 
-server-john:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=John
+  server-paul:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Paul
 
-server-paul:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Paul
+  server-george:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=George
 
-server-george:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=George
+  server-ringo:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Ringo
 
-server-ringo:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Ringo
-
-redis:
-  image: redis:alpine
-  expose:
-    - "6379"
+  redis:
+    image: redis:alpine
+    expose:
+      - "6379"

examples/cluster-haproxy/haproxy/Dockerfile

@@ -1,2 +0,0 @@
-FROM haproxy:1.7-alpine
-COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg

examples/cluster-haproxy/server/package.json

@@ -8,7 +8,7 @@
   "license": "BSD",
   "dependencies": {
     "express": "4.13.4",
-    "socket.io": "^3.1.0",
+    "socket.io": "^4.0.0",
     "socket.io-redis": "^6.0.1"
   },
   "scripts": {

examples/cluster-httpd/docker-compose.yml

@@ -1,51 +1,53 @@
+services:
+  httpd:
+    image: httpd:2.4-alpine
+    volumes:
+      - ./httpd.conf:/usr/local/apache2/conf/httpd.conf:ro
+    links:
+      - server-john
+      - server-paul
+      - server-george
+      - server-ringo
+    ports:
+     - "3000:80"
 
-httpd:
-  build: ./httpd
-  links:
-    - server-john
-    - server-paul
-    - server-george
-    - server-ringo
-  ports:
-   - "3000:80"
+  server-john:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=John
 
-server-john:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=John
+  server-paul:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Paul
 
-server-paul:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Paul
+  server-george:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=George
 
-server-george:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=George
+  server-ringo:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Ringo
 
-server-ringo:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Ringo
-
-redis:
-  image: redis:alpine
-  expose:
-    - "6379"
+  redis:
+    image: redis:6
+    expose:
+      - "6379"

examples/cluster-httpd/httpd.conf

@@ -51,4 +51,5 @@ RewriteRule /(.*) balancer://nodes_ws/$1 [P,L]
 RewriteCond %{HTTP:Upgrade} !=websocket [NC]
 RewriteRule /(.*) balancer://nodes_polling/$1 [P,L]
 
-ProxyTimeout 3
+# must be bigger than pingInterval (25s by default) + pingTimeout (20s by default)
+ProxyTimeout 60

examples/cluster-httpd/httpd/Dockerfile

@@ -1,2 +0,0 @@
-FROM httpd:2.4-alpine
-COPY ./httpd.conf /usr/local/apache2/conf/httpd.conf

examples/cluster-httpd/server/Dockerfile

@@ -1,4 +1,4 @@
-FROM mhart/alpine-node:6
+FROM node:14-alpine
 
 # Create app directory
 RUN mkdir -p /usr/src/app

examples/cluster-httpd/server/package.json

@@ -8,7 +8,7 @@
   "license": "BSD",
   "dependencies": {
     "express": "4.13.4",
-    "socket.io": "^3.1.0",
+    "socket.io": "^4.0.0",
     "socket.io-redis": "^6.0.1"
   },
   "scripts": {

examples/cluster-nginx/client/package.json

@@ -7,7 +7,7 @@
   "private": true,
   "license": "MIT",
   "dependencies": {
-    "socket.io-client": "^3.1.0"
+    "socket.io-client": "^4.0.0"
   },
   "scripts": {
     "start": "node index.js"

examples/cluster-nginx/docker-compose.yml

@@ -1,56 +1,58 @@
+services:
+  nginx:
+    image: nginx:alpine
+    volumes:
+      - ./nginx.conf:/etc/nginx/nginx.conf:ro
+    links:
+      - server-john
+      - server-paul
+      - server-george
+      - server-ringo
+    ports:
+     - "3000:80"
 
-nginx:
-  build: ./nginx
-  links:
-    - server-john
-    - server-paul
-    - server-george
-    - server-ringo
-  ports:
-   - "3000:80"
+  server-john:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=John
 
-server-john:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=John
+  server-paul:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Paul
 
-server-paul:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Paul
+  server-george:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=George
 
-server-george:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=George
+  server-ringo:
+    build: ./server
+    links:
+      - redis
+    expose:
+      - "3000"
+    environment:
+      - NAME=Ringo
 
-server-ringo:
-  build: ./server
-  links:
-    - redis
-  expose:
-    - "3000"
-  environment:
-    - NAME=Ringo
+  client:
+    build: ./client
+    links:
+      - nginx
 
-client:
-  build: ./client
-  links:
-    - nginx
-
-redis:
-  image: redis:alpine
-  expose:
-    - "6379"
+  redis:
+    image: redis:6
+    expose:
+      - "6379"

examples/cluster-nginx/nginx/Dockerfile

@@ -1,3 +0,0 @@
-
-FROM nginx:alpine
-COPY nginx.conf /etc/nginx/nginx.conf

examples/cluster-nginx/server/index.js

@@ -1,15 +1,18 @@
-// Setup basic express server
-var express = require('express');
-var app = express();
-var server = require('http').createServer(app);
-var io = require('socket.io')(server);
-var redis = require('socket.io-redis');
-var port = process.env.PORT || 3000;
-var serverName = process.env.NAME || 'Unknown';
+const express = require('express');
+const app = express();
+const server = require('http').createServer(app);
+const io = require('socket.io')(server);
+const { createAdapter } = require('@socket.io/redis-adapter');
+const { createClient } = require('redis');
+const port = process.env.PORT || 3000;
+const serverName = process.env.NAME || 'Unknown';
 
-io.adapter(redis({ host: 'redis', port: 6379 }));
+const pubClient = createClient({ host: 'redis', port: 6379 });
+const subClient = pubClient.duplicate();
 
-server.listen(port, function () {
+io.adapter(createAdapter(pubClient, subClient));
+
+server.listen(port, () => {
   console.log('Server listening at port %d', port);
   console.log('Hello, I\'m %s, how can I help?', serverName);
 });
@@ -19,15 +22,15 @@ app.use(express.static(__dirname + '/public'));
 
 // Chatroom
 
-var numUsers = 0;
+let numUsers = 0;
 
-io.on('connection', function (socket) {
+io.on('connection', socket => {
   socket.emit('my-name-is', serverName);
 
-  var addedUser = false;
+  let addedUser = false;
 
   // when the client emits 'new message', this listens and executes
-  socket.on('new message', function (data) {
+  socket.on('new message', data => {
     // we tell the client to execute 'new message'
     socket.broadcast.emit('new message', {
       username: socket.username,
@@ -36,7 +39,7 @@ io.on('connection', function (socket) {
   });
 
   // when the client emits 'add user', this listens and executes
-  socket.on('add user', function (username) {
+  socket.on('add user', username => {
     if (addedUser) return;
 
     // we store the username in the socket session for this client
@@ -54,21 +57,21 @@ io.on('connection', function (socket) {
   });
 
   // when the client emits 'typing', we broadcast it to others
-  socket.on('typing', function () {
+  socket.on('typing', () => {
     socket.broadcast.emit('typing', {
       username: socket.username
     });
   });
 
   // when the client emits 'stop typing', we broadcast it to others
-  socket.on('stop typing', function () {
+  socket.on('stop typing', () => {
     socket.broadcast.emit('stop typing', {
       username: socket.username
     });
   });
 
   // when the user disconnects.. perform this
-  socket.on('disconnect', function () {
+  socket.on('disconnect', () => {
     if (addedUser) {
       --numUsers;
 

examples/cluster-nginx/server/package.json

@@ -7,9 +7,10 @@
   "private": true,
   "license": "MIT",
   "dependencies": {
+    "@socket.io/redis-adapter": "^7.0.1",
     "express": "4.13.4",
-    "socket.io": "^3.1.0",
-    "socket.io-redis": "^6.0.1"
+    "redis": "^3.1.2",
+    "socket.io": "^4.0.0"
   },
   "scripts": {
     "start": "node index.js"

examples/cluster-traefik/server/package.json

@@ -8,7 +8,7 @@
   "license": "MIT",
   "dependencies": {
     "express": "4.13.4",
-    "socket.io": "^3.1.0",
+    "socket.io": "^4.0.0",
     "socket.io-redis": "^6.0.1"
   },
   "scripts": {

examples/create-react-app-example/package.json

@@ -3,14 +3,14 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
-    "@testing-library/jest-dom": "^4.2.4",
-    "@testing-library/react": "^9.3.2",
-    "@testing-library/user-event": "^7.1.2",
-    "react": "^16.13.1",
-    "react-dom": "^16.13.1",
-    "react-scripts": "3.4.1",
-    "socket.io": "^2.3.0",
-    "socket.io-client": "^2.3.0"
+    "@testing-library/jest-dom": "^5.16.5",
+    "@testing-library/react": "^14.0.0",
+    "@testing-library/user-event": "^14.4.3",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-scripts": "^5.0.1",
+    "socket.io": "^4.6.1",
+    "socket.io-client": "^4.6.1"
   },
   "scripts": {
     "start": "react-scripts start",

examples/create-react-app-example/server.js

@@ -1,4 +1,8 @@
-const io = require('socket.io')();
+const io = require('socket.io')({
+  cors: {
+    origin: ['http://localhost:3000']
+  }
+});
 
 io.on('connection', socket => {
   console.log(`connect: ${socket.id}`);

examples/create-react-app-example/src/App.js

@@ -1,4 +1,5 @@
 import React, { useState, useEffect } from 'react';
+import logo from './logo.svg';
 import './App.css';
 import io from 'socket.io-client';
 
@@ -23,7 +24,7 @@ function App() {
       socket.off('disconnect');
       socket.off('message');
     };
-  });
+  }, []);
 
   const sendMessage = () => {
     socket.emit('hello!');
@@ -32,9 +33,21 @@ function App() {
   return (
     <div className="App">
       <header className="App-header">
+        <img src={logo} className="App-logo" alt="logo" />
         <p>Connected: { '' + isConnected }</p>
         <p>Last message: { lastMessage || '-' }</p>
         <button onClick={ sendMessage }>Say hello!</button>
+        <p>
+          Edit <code>src/App.js</code> and save to reload.
+        </p>
+        <a
+          className="App-link"
+          href="https://reactjs.org"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          Learn React
+        </a>
       </header>
     </div>
   );

examples/create-react-app-example/src/index.js

@@ -1,14 +1,15 @@
 import React from 'react';
-import ReactDOM from 'react-dom';
+import { createRoot } from 'react-dom/client';
 import './index.css';
 import App from './App';
 import * as serviceWorker from './serviceWorker';
 
-ReactDOM.render(
+const container = document.getElementById('root');
+const root = createRoot(container)
+root.render(
   <React.StrictMode>
     <App />
-  </React.StrictMode>,
-  document.getElementById('root')
+  </React.StrictMode>
 );
 
 // If you want your app to work offline and load faster, you can change

examples/custom-parsers/package.json

@@ -12,10 +12,10 @@
     "component-emitter": "^1.2.1",
     "express": "^4.15.2",
     "schemapack": "^1.4.2",
-    "socket.io": "socketio/socket.io",
-    "socket.io-client": "socketio/socket.io-client",
-    "socket.io-json-parser": "^1.0.0",
-    "socket.io-msgpack-parser": "^1.0.0",
+    "socket.io": "^4.0.0",
+    "socket.io-client": "^4.0.0",
+    "socket.io-json-parser": "^3.0.0",
+    "socket.io-msgpack-parser": "^3.0.1",
     "webpack": "^2.4.1"
   }
 }