docs(examples): bump dependencies for the private messaging example

Diff: https://github.com/socketio/socket.io/compare/3.1.0...3.1.1

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,61 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: 'bug'
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+
+Please fill the following code example:
+
+Socket.IO server version: `x.y.z`
+
+*Server*
+
+```js
+import { Server } from "socket.io";
+
+const io = new Server(3000, {});
+
+io.on("connection", (socket) => {
+  console.log(`connect ${socket.id}`);
+
+  socket.on("disconnect", () => {
+    console.log(`disconnect ${socket.id}`);
+  });
+});
+```
+
+Socket.IO client version: `x.y.z`
+
+*Client*
+
+```js
+import { io } from "socket.io-client";
+
+const socket = io("ws://localhost:3000/", {});
+
+socket.on("connect", () => {
+  console.log(`connect ${socket.id}`);
+});
+
+socket.on("disconnect", () => {
+  console.log("disconnect");
+});
+```
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Platform:**
+ - Device: [e.g. Samsung S8]
+ - OS: [e.g. Android 9.2]
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Ask a Question
+    url: https://github.com/socketio/socket.io/discussions/new?category=q-a
+    about: Ask the community for help

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: 'enhancement'
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,18 @@
+
+### The kind of change this PR does introduce
+
+* [x] a bug fix
+* [ ] a new feature
+* [ ] an update to the documentation
+* [ ] a code change that improves performance
+* [ ] other
+
+### Current behavior
+
+
+### New behavior
+
+
+### Other information (e.g. related issues)
+
+

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 0 * * 0'
+
+jobs:
+  test-node:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x, 14.x, 15.x]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm test
+        env:
+          CI: true

.gitignore

@@ -9,3 +9,6 @@ lib-cov
 benchmarks/*.png
 node_modules
 coverage
+.idea
+.nyc_output
+dist/

.npmignore

@@ -1,4 +0,0 @@
-support
-test
-examples
-.gitignore

.replit

@@ -0,0 +1,2 @@
+language = "nodejs"
+run = "npm start"

.travis.yml

@@ -1,16 +0,0 @@
-language: node_js
-node_js:
-  - "0.8"
-  - "0.10"
-  - "0.11"
-
-git:
-  depth: 1
-
-matrix:
-  fast_finish: true
-  allow_failures:
-    - node_js: "0.11"
-
-notifications:
-  irc: "irc.freenode.org#socket.io"

CHANGELOG.md

@@ -0,0 +1,324 @@
+## [3.1.1](https://github.com/socketio/socket.io/compare/3.1.0...3.1.1) (2021-02-03)
+
+
+### Bug Fixes
+
+* properly parse the CONNECT packet in v2 compatibility mode ([6f4bd7f](https://github.com/socketio/socket.io/commit/6f4bd7f8e7c41a075a8014565330a77c38b03a8d))
+* **typings:** add return types and general-case overload signatures ([#3776](https://github.com/socketio/socket.io/issues/3776)) ([9e8f288](https://github.com/socketio/socket.io/commit/9e8f288ca9f14f91064b8d3cce5946f7d23d407c))
+* **typings:** update the types of "query", "auth" and "headers" ([4f2e9a7](https://github.com/socketio/socket.io/commit/4f2e9a716d9835b550c8fd9a9b429ebf069c2895))
+
+
+# [3.1.0](https://github.com/socketio/socket.io/compare/3.0.5...3.1.0) (2021-01-15)
+
+
+### Features
+
+* confirm a weak but matching ETag ([#3485](https://github.com/socketio/socket.io/issues/3485)) ([161091d](https://github.com/socketio/socket.io/commit/161091dd4c9e1b1610ac3d45d964195e63d92b94))
+* **esm:** export the Namespace and Socket class ([#3699](https://github.com/socketio/socket.io/issues/3699)) ([233650c](https://github.com/socketio/socket.io/commit/233650c22209708b5fccc4349c38d2fa1b465d8f))
+* add support for Socket.IO v2 clients ([9925746](https://github.com/socketio/socket.io/commit/9925746c8ee3a6522bd640b5d586c83f04f2f1ba))
+* add room events ([155fa63](https://github.com/socketio/socket.io-adapter/commit/155fa6333a504036e99a33667dc0397f6aede25e))
+
+
+### Bug Fixes
+
+* allow integers as event names ([1c220dd](https://github.com/socketio/socket.io-parser/commit/1c220ddbf45ea4b44bc8dbf6f9ae245f672ba1b9))
+
+
+## [3.0.5](https://github.com/socketio/socket.io/compare/3.0.4...3.0.5) (2021-01-05)
+
+
+### Bug Fixes
+
+* properly clear timeout on connection failure ([170b739](https://github.com/socketio/socket.io/commit/170b739f147cb6c92b423729b877e242e376927d))
+
+
+### Reverts
+
+* restore the socket middleware functionality ([bf54327](https://github.com/socketio/socket.io/commit/bf5432742158e4d5ba2722cff4a614967dffa5b9))
+
+
+## [3.0.4](https://github.com/socketio/socket.io/compare/3.0.3...3.0.4) (2020-12-07)
+
+
+## [3.0.3](https://github.com/socketio/socket.io/compare/3.0.2...3.0.3) (2020-11-19)
+
+
+## [3.0.2](https://github.com/socketio/socket.io/compare/3.0.1...3.0.2) (2020-11-17)
+
+
+### Bug Fixes
+
+* merge Engine.IO options ([43705d7](https://github.com/socketio/socket.io/commit/43705d7a9149833afc69edc937ea7f8c9aabfeef))
+
+
+## [3.0.1](https://github.com/socketio/socket.io/compare/3.0.0...3.0.1) (2020-11-09)
+
+
+### Bug Fixes
+
+* export ServerOptions and Namespace types ([#3684](https://github.com/socketio/socket.io/issues/3684)) ([f62f180](https://github.com/socketio/socket.io/commit/f62f180edafdd56d8a8a277e092bc66df0c5f07f))
+* **typings:** update the signature of the emit method ([50671d9](https://github.com/socketio/socket.io/commit/50671d984a81535a6a15c704546ca7465e2ea295))
+
+
+# [3.0.0](https://github.com/socketio/socket.io/compare/2.3.0...3.0.0) (2020-11-05)
+
+### Bug Fixes
+
+* close clients with no namespace ([91cd255](https://github.com/socketio/socket.io/commit/91cd255ba76ff6a780c62740f9f5cd3a76f5d7c7))
+
+### Features
+
+* emit an Error object upon middleware error ([54bf4a4](https://github.com/socketio/socket.io/commit/54bf4a44e9e896dfb64764ee7bd4e8823eb7dc7b))
+* serve msgpack bundle ([aa7574f](https://github.com/socketio/socket.io/commit/aa7574f88471aa30ae472a5cddf1000a8baa70fd))
+* add support for catch-all listeners ([5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))
+* make Socket#join() and Socket#leave() synchronous ([129c641](https://github.com/socketio/socket.io/commit/129c6417bd818bc8b4e1b831644323876e627c13))
+* remove prod dependency to socket.io-client ([7603da7](https://github.com/socketio/socket.io/commit/7603da71a535481e3fc60e38b013abf78516d322))
+* move binary detection back to the parser ([669592d](https://github.com/socketio/socket.io/commit/669592d120409a5cf00f128070dee6d22259ba4f))
+* add ES6 module export ([8b6b100](https://github.com/socketio/socket.io/commit/8b6b100c284ccce7d85e55659e3397f533916847))
+* do not reuse the Engine.IO id ([2875d2c](https://github.com/socketio/socket.io/commit/2875d2cfdfa463e64cb520099749f543bbc4eb15))
+* remove Server#set() method ([029f478](https://github.com/socketio/socket.io/commit/029f478992f59b1eb5226453db46363a570eea46))
+* remove Socket#rooms object ([1507b41](https://github.com/socketio/socket.io/commit/1507b416d584381554d1ed23c9aaf3b650540071))
+* remove the 'origins' option ([a8c0600](https://github.com/socketio/socket.io/commit/a8c06006098b512ba1b8b8df82777349db486f41))
+* remove the implicit connection to the default namespace ([3289f7e](https://github.com/socketio/socket.io/commit/3289f7ec376e9ec88c2f90e2735c8ca8d01c0e97))
+* throw upon reserved event names ([4bd5b23](https://github.com/socketio/socket.io/commit/4bd5b2339a66a5a675e20f689fff2e70ff12d236))
+
+### BREAKING CHANGES
+
+* the Socket#use() method is removed (see [5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))
+
+* Socket#join() and Socket#leave() do not accept a callback argument anymore.
+
+Before:
+
+```js
+socket.join("room1", () => {
+ io.to("room1").emit("hello");
+});
+```
+
+After:
+
+```js
+socket.join("room1");
+io.to("room1").emit("hello");
+// or await socket.join("room1"); for custom adapters
+```
+
+* the "connected" map is renamed to "sockets"
+* the Socket#binary() method is removed, as this use case is now covered by the ability to provide your own parser.
+* the 'origins' option is removed
+
+Before:
+
+```js
+new Server(3000, {
+  origins: ["https://example.com"]
+});
+```
+
+The 'origins' option was used in the allowRequest method, in order to
+determine whether the request should pass or not. And the Engine.IO
+server would implicitly add the necessary Access-Control-Allow-xxx
+headers.
+
+After:
+
+```js
+new Server(3000, {
+  cors: {
+    origin: "https://example.com",
+    methods: ["GET", "POST"],
+    allowedHeaders: ["content-type"]
+  }
+});
+```
+
+The already existing 'allowRequest' option can be used for validation:
+
+```js
+new Server(3000, {
+  allowRequest: (req, callback) => {
+    callback(null, req.headers.referer.startsWith("https://example.com"));
+  }
+});
+```
+
+* Socket#rooms is now a Set instead of an object
+
+* Namespace#connected is now a Map instead of an object
+
+* there is no more implicit connection to the default namespace:
+
+```js
+// client-side
+const socket = io("/admin");
+
+// server-side
+io.on("connect", socket => {
+  // not triggered anymore
+})
+
+io.use((socket, next) => {
+  // not triggered anymore
+});
+
+io.of("/admin").use((socket, next) => {
+  // triggered
+});
+```
+
+* the Server#set() method was removed
+
+This method was kept for backward-compatibility with pre-1.0 versions.
+
+
+# [3.0.0-rc4](https://github.com/socketio/socket.io/compare/3.0.0-rc3...3.0.0-rc4) (2020-10-30)
+
+
+### Features
+
+* emit an Error object upon middleware error ([54bf4a4](https://github.com/socketio/socket.io/commit/54bf4a44e9e896dfb64764ee7bd4e8823eb7dc7b))
+* serve msgpack bundle ([aa7574f](https://github.com/socketio/socket.io/commit/aa7574f88471aa30ae472a5cddf1000a8baa70fd))
+
+
+
+# [3.0.0-rc3](https://github.com/socketio/socket.io/compare/3.0.0-rc2...3.0.0-rc3) (2020-10-26)
+
+
+### Features
+
+* add support for catch-all listeners ([5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))
+* make Socket#join() and Socket#leave() synchronous ([129c641](https://github.com/socketio/socket.io/commit/129c6417bd818bc8b4e1b831644323876e627c13))
+* remove prod dependency to socket.io-client ([7603da7](https://github.com/socketio/socket.io/commit/7603da71a535481e3fc60e38b013abf78516d322))
+
+
+### BREAKING CHANGES
+
+* the Socket#use() method is removed (see [5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))
+
+* Socket#join() and Socket#leave() do not accept a callback argument anymore.
+
+Before:
+
+```js
+socket.join("room1", () => {
+ io.to("room1").emit("hello");
+});
+```
+
+After:
+
+```js
+socket.join("room1");
+io.to("room1").emit("hello");
+// or await socket.join("room1"); for custom adapters
+```
+
+
+
+# [3.0.0-rc2](https://github.com/socketio/socket.io/compare/3.0.0-rc1...3.0.0-rc2) (2020-10-15)
+
+
+### Bug Fixes
+
+* close clients with no namespace ([91cd255](https://github.com/socketio/socket.io/commit/91cd255ba76ff6a780c62740f9f5cd3a76f5d7c7))
+
+
+### Code Refactoring
+
+* remove duplicate _sockets map ([8a5db7f](https://github.com/socketio/socket.io/commit/8a5db7fa36a075da75cde43cd4fb6382b7659953))
+
+
+### Features
+
+* move binary detection back to the parser ([669592d](https://github.com/socketio/socket.io/commit/669592d120409a5cf00f128070dee6d22259ba4f))
+
+
+### BREAKING CHANGES
+
+* the "connected" map is renamed to "sockets"
+* the Socket#binary() method is removed, as this use case is now covered by the ability to provide your own parser.
+
+
+
+# [3.0.0-rc1](https://github.com/socketio/socket.io/compare/2.3.0...3.0.0-rc1) (2020-10-13)
+
+
+### Features
+
+* add ES6 module export ([8b6b100](https://github.com/socketio/socket.io/commit/8b6b100c284ccce7d85e55659e3397f533916847))
+* do not reuse the Engine.IO id ([2875d2c](https://github.com/socketio/socket.io/commit/2875d2cfdfa463e64cb520099749f543bbc4eb15))
+* remove Server#set() method ([029f478](https://github.com/socketio/socket.io/commit/029f478992f59b1eb5226453db46363a570eea46))
+* remove Socket#rooms object ([1507b41](https://github.com/socketio/socket.io/commit/1507b416d584381554d1ed23c9aaf3b650540071))
+* remove the 'origins' option ([a8c0600](https://github.com/socketio/socket.io/commit/a8c06006098b512ba1b8b8df82777349db486f41))
+* remove the implicit connection to the default namespace ([3289f7e](https://github.com/socketio/socket.io/commit/3289f7ec376e9ec88c2f90e2735c8ca8d01c0e97))
+* throw upon reserved event names ([4bd5b23](https://github.com/socketio/socket.io/commit/4bd5b2339a66a5a675e20f689fff2e70ff12d236))
+
+
+### BREAKING CHANGES
+
+* the 'origins' option is removed
+
+Before:
+
+```js
+new Server(3000, {
+  origins: ["https://example.com"]
+});
+```
+
+The 'origins' option was used in the allowRequest method, in order to
+determine whether the request should pass or not. And the Engine.IO
+server would implicitly add the necessary Access-Control-Allow-xxx
+headers.
+
+After:
+
+```js
+new Server(3000, {
+  cors: {
+    origin: "https://example.com",
+    methods: ["GET", "POST"],
+    allowedHeaders: ["content-type"]
+  }
+});
+```
+
+The already existing 'allowRequest' option can be used for validation:
+
+```js
+new Server(3000, {
+  allowRequest: (req, callback) => {
+    callback(null, req.headers.referer.startsWith("https://example.com"));
+  }
+});
+```
+
+* Socket#rooms is now a Set instead of an object
+
+* Namespace#connected is now a Map instead of an object
+
+* there is no more implicit connection to the default namespace:
+
+```js
+// client-side
+const socket = io("/admin");
+
+// server-side
+io.on("connect", socket => {
+  // not triggered anymore
+})
+
+io.use((socket, next) => {
+  // not triggered anymore
+});
+
+io.of("/admin").use((socket, next) => {
+  // triggered
+});
+```
+
+* the Server#set() method was removed
+
+This method was kept for backward-compatibility with pre-1.0 versions.
+

History.md

@@ -1,451 +0,0 @@
-
-1.2.1 / 2014-11-21
-==================
-
- * fix protocol violations and improve error handling (GH-1880)
- * package: bump `engine.io` for websocket leak fix [3rd-Eden]
- * style tweaks
-
-1.2.0 / 2014-10-27
-==================
-
- * package: bump `engine.io`
- * downloads badge
- * add test to check that empty rooms are autopruned
- * added Server#origins(v:Function) description for dynamic CORS
- * added test coverage for Server#origins(function) for dynamic CORS
- * added optional Server#origins(function) for dynamic CORS
- * fix usage example for Server#close
- * package: fix main file for example application 'chat'
- * package: bump `socket.io-parser`
- * update README http ctor to createServer()
- * bump adapter with a lot of fixes for room bookkeeping
-
-1.1.0 / 2014-09-04
-==================
-
- * examples: minor fix of escaping
- * testing for equivalence of namespaces starting with / or without
- * update index.js
- * added relevant tests
- * take "" and "/" as equivalent namespaces on server
- * use svg instead of png to get better image quality in readme
- * make CI build faster
- * fix splice arguments and `socket.rooms` value update in `socket.leaveAll`.
- * client cannot connect to non-existing namespaces
- * bump engine.io version to get the cached IP address
- * fixed handshake object address property and made the test case more strict.
- * package: bump `engine.io`
- * fixed the failing test where server crashes on disconnect involving connectBuffer
- * npmignore: ignore `.gitignore` (fixes #1607)
- * test: added failing case for `socket.disconnect` and nsps
- * fix repo in package.json
- * improve Close documentation
- * use ephemeral ports
- * fix: We should use the standard http protocol to handler the etag header.
- * override default browser font-family for inputs
- * update has-binary-data to 1.0.3
- * add close specs
- * add ability to stop the http server even if not created inside socket.io
- * make sure server gets close
- * Add test case for checking that reconnect_failed is fired only once upon failure
- * package: bump `socket.io-parser` for `component-emitter` dep fix
-
-1.0.6 / 2014-06-19
-==================
-
- * package: bump `socket.io-client`
-
-1.0.5 / 2014-06-16
-==================
-
- * package: bump `engine.io` to fix jsonp `\n` bug and CORS warnings
- * index: fix typo [yanatan16]
- * add `removeListener` to blacklisted events
- * examples: clearer instructions to install chat example
- * index: fix namespace `connectBuffer` issue
-
-1.0.4 / 2014-06-02
-==================
-
- * package: bump socket.io-client
-
-1.0.3 / 2014-05-31
-==================
-
- * package: bump `socket.io-client`
- * package: bump `socket.io-parser` for binary ACK fix
- * package: bump `engine.io` for binary UTF8 fix
- * example: fix XSS in chat example
-
-1.0.2 / 2014-05-28
-==================
-
- * package: bump `socket.io-parser` for windows fix
-
-1.0.1 / 2014-05-28
-==================
-
- * bump due to bad npm tag
-
-1.0.0 / 2014-05-28
-==================
-
- * stable release
-
-1.0.0-pre5 / 2014-05-22
-=======================
-
- * package: bump `socket.io-client` for parser fixes
- * package: bump `engine.io`
-
-1.0.0-pre4 / 2014-05-19
-=======================
-
- * package: bump client
-
-1.0.0-pre3 / 2014-05-17
-=======================
-
- * package: bump parser
- * package: bump engine.io
-
-1.0.0-pre2 / 2014-04-27
-=======================
-
- * package: bump `engine.io`
- * added backwards compatible of engine.io maxHttpBufferSize
- * added test that server and client using same protocol
- * added support for setting allowed origins
- * added information about logging
- * the set function in server can be used to set some attributes for BC
- * fix error in callback call 'done' instead of 'next' in docs
- * package: bump `socket.io-parser`
- * package: bump `expect.js`
- * added some new tests, including binary with acks
-
-1.0.0-pre / 2014-03-14
-======================
-
- * implemented `engine.io`
- * implemented `socket.io-adapter`
- * implemented `socket.io-protocol`
- * implemented `debug` and improved instrumentation
- * added binary support
- * added new `require('io')(srv)` signature
- * simplified `socket.io-client` serving
-
-0.9.14 / 2013-03-29
-===================
-
-  * manager: fix memory leak with SSL [jpallen]
-
-0.9.13 / 2012-12-13
-===================
-
-  * package: fixed `base64id` requirement
-
-0.9.12 / 2012-12-13
-===================
-
-  * manager: fix for latest node which is returning a clone with `listeners` [viirya]
-
-0.9.11 / 2012-11-02
-===================
-
-  * package: move redis to optionalDependenices [3rd-Eden]
-  * bumped client
-
-0.9.10 / 2012-08-10
-===================
-
-  * Don't lowercase log messages
-  * Always set the HTTP response in case an error should be returned to the client
-  * Create or destroy the flash policy server on configuration change
-  * Honour configuration to disable flash policy server
-  * Add express 3.0 instructions on Readme.md
-  * Bump client
-
-0.9.9 / 2012-08-01
-==================
-
-  * Fixed sync disconnect xhrs handling
-  * Put license text in its own file (#965)
-  * Add warning to .listen() to ease the migration to Express 3.x
-  * Restored compatibility with node 0.4.x
-
-0.9.8 / 2012-07-24
-==================
-
-  * Bumped client.
-
-0.9.7 / 2012-07-24
-==================
-
-  * Prevent crash when socket leaves a room twice.
-  * Corrects unsafe usage of for..in
-  * Fix for node 0.8 with `gzip compression` [vadimi]
-  * Update redis to support Node 0.8.x
-  * Made ID generation securely random
-  * Fix Redis Store race condition in manager onOpen unsubscribe callback
-  * Fix for EventEmitters always reusing the same Array instance for listeners
-
-0.9.6 / 2012-04-17
-==================
-
-  * Fixed XSS in jsonp-polling.
-
-0.9.5 / 2012-04-05
-==================
-
-  * Added test for polling and socket close.
-  * Ensure close upon request close.
-  * Fix disconnection reason being lost for polling transports.
-  * Ensure that polling transports work with Connection: close.
-  * Log disconnection reason.
-
-0.9.4 / 2012-04-01
-==================
-
-  * Disconnecting from namespace improvement (#795) [DanielBaulig]
-  * Bumped client with polling reconnection loop (#438)
-
-0.9.3 / 2012-03-28
-==================
-
-  * Fix "Syntax error" on FF Web Console with XHR Polling [mikito]
-
-0.9.2 / 2012-03-13
-==================
-
-  * More sensible close `timeout default` (fixes disconnect issue)
-
-0.9.1-1 / 2012-03-02
-====================
-
-  * Bumped client with NPM dependency fix.
-
-0.9.1 / 2012-03-02
-==================
-
-  * Changed heartbeat timeout and interval defaults (60 and 25 seconds)
-  * Make tests work both on 0.4 and 0.6
-  * Updated client (improvements + bug fixes).
-
-0.9.0 / 2012-02-26
-==================
-
-  * Make it possible to use a regexp to match the socket.io resource URL.
-    We need this because we have to prefix the socket.io URL with a variable ID.
-  * Supplemental fix to gavinuhma/authfix, it looks like the same Access-Control-Origin logic is needed in the http and xhr-polling transports
-  * Updated express dep for windows compatibility.
-  * Combine two substr calls into one in decodePayload to improve performance
-  * Minor documentation fix
-  * Minor. Conform to style of other files.
-  * Switching setting to 'match origin protocol'
-  * Revert "Fixes leaking Redis subscriptions for #663. The local flag was not getting passed through onClientDisconnect()."
-  * Revert "Handle leaked dispatch:[id] subscription."
-  * Merge pull request #667 from dshaw/patch/redis-disconnect
-  * Handle leaked dispatch:[id] subscription.
-  * Fixes leaking Redis subscriptions for #663. The local flag was not getting passed through onClientDisconnect().
-  * Prevent memory leaking on uncompleted requests & add max post size limitation
-  * Fix for testcase
-  * Set Access-Control-Allow-Credentials true, regardless of cookie
-  * Remove assertvarnish from package as it breaks on 0.6
-  * Correct irc channel
-  * Added proper return after reserved field error
-  * Fixes manager.js failure to close connection after transport error has happened
-  * Added implicit port 80 for origin checks. fixes #638
-  * Fixed bug #432 in 0.8.7
-  * Set Access-Control-Allow-Origin header to origin to enable withCredentials
-  * Adding configuration variable matchOriginProtocol
-  * Fixes location mismatch error in Safari.
-  * Use tty to detect if we should add colors or not by default.
-  * Updated the package location.
-
-0.8.7 / 2011-11-05
-==================
-
-  * Fixed memory leaks in closed clients.
-  * Fixed memory leaks in namespaces.
-  * Fixed websocket handling for malformed requests from proxies. [einaros]
-  * Node 0.6 compatibility. [einaros] [3rd-Eden]
-  * Adapted tests and examples.
-
-0.8.6 / 2011-10-27 
-==================
-
-  * Added JSON decoding on jsonp-polling transport.
-  * Fixed README example.
-  * Major speed optimizations [3rd-Eden] [einaros] [visionmedia]
-  * Added decode/encode benchmarks [visionmedia]
-  * Added support for black-listing client sent events.
-  * Fixed logging options, closes #540 [3rd-Eden]
-  * Added vary header for gzip [3rd-Eden]
-  * Properly cleaned up async websocket / flashsocket tests, after patching node-websocket-client
-  * Patched to properly shut down when a finishClose call is made during connection establishment
-  * Added support for socket.io version on url and far-future Expires [3rd-Eden] [getify]
-  * Began IE10 compatibility [einaros] [tbranyen]
-  * Misc WebSocket fixes [einaros]
-  * Added UTF8 to respone headers for htmlfile [3rd-Eden]
-
-0.8.5 / 2011-10-07
-==================
-
-  * Added websocket draft HyBi-16 support. [einaros]
-  * Fixed websocket continuation bugs. [einaros]
-  * Fixed flashsocket transport name.
-  * Fixed websocket tests.
-  * Ensured `parser#decodePayload` doesn't choke.
-  * Added http referrer verification to manager verifyOrigin.
-  * Added access control for cross domain xhr handshakes [3rd-Eden]
-  * Added support for automatic generation of socket.io files [3rd-Eden]
-  * Added websocket binary support [einaros]
-  * Added gzip support for socket.io.js [3rd-Eden]
-  * Expose socket.transport [3rd-Eden]
-  * Updated client.
-
-0.8.4 / 2011-09-06
-==================
-
-  * Client build
-
-0.8.3 / 2011-09-03
-==================
-
-  * Fixed `\n` parsing for non-JSON packets (fixes #479).
-  * Fixed parsing of certain unicode characters (fixes #451).
-  * Fixed transport message packet logging.
-  * Fixed emission of `error` event resulting in an uncaught exception if unhandled (fixes #476).
-  * Fixed; allow for falsy values as the configuration value of `log level` (fixes #491).
-  * Fixed repository URI in `package.json`. Fixes #504.
-  * Added text/plain content-type to handshake responses [einaros]
-  * Improved single byte writes [einaros]
-  * Updated socket.io-flashsocket default port from 843 to 10843 [3rd-Eden]
-  * Updated client.
-
-0.8.2 / 2011-08-29
-==================
-
-  * Updated client.
-
-0.8.1 / 2011-08-29
-==================
-
-  * Fixed utf8 bug in send framing in websocket [einaros]
-  * Fixed typo in docs [Znarkus]
-  * Fixed bug in send framing for over 64kB of data in websocket [einaros]
-  * Corrected ping handling in websocket transport [einaros]
-
-0.8.0 / 2011-08-28
-==================
-
-  * Updated to work with two-level websocket versioning. [einaros]
-  * Added hybi07 support. [einaros]
-  * Added hybi10 support. [einaros]
-  * Added http referrer verification to manager.js verifyOrigin. [einaors]
-
-0.7.11 / 2011-08-27
-===================
-
-  * Updated socket.io-client.
-
-0.7.10 / 2011-08-27
-===================
-
-  * Updated socket.io-client.
-
-0.7.9 / 2011-08-12
-==================
-
-  * Updated socket.io-client.
-  * Make sure we only do garbage collection when the server we receive is actually run.
-
-0.7.8 / 2011-08-08
-==================
-
-  * Changed; make sure sio#listen passes options to both HTTP server and socket.io manager.
-  * Added docs for sio#listen.
-  * Added options parameter support for Manager constructor.
-  * Added memory leaks tests and test-leaks Makefile task.
-  * Removed auto npm-linking from make test.
-  * Make sure that you can disable heartbeats. [3rd-Eden]
-  * Fixed rooms memory leak [3rd-Eden]
-  * Send response once we got all POST data, not immediately [Pita]
-  * Fixed onLeave behavior with missing clientsk [3rd-Eden]
-  * Prevent duplicate references in rooms.
-  * Added alias for `to` to `in` and `in` to `to`.
-  * Fixed roomClients definition.
-  * Removed dependency on redis for installation without npm [3rd-Eden]
-  * Expose path and querystring in handshakeData [3rd-Eden]
-
-0.7.7 / 2011-07-12
-==================
-
-  * Fixed double dispatch handling with emit to closed clients.
-  * Added test for emitting to closed clients to prevent regression.
-  * Fixed race condition in redis test.
-  * Changed Transport#end instrumentation.
-  * Leveraged $emit instead of emit internally.
-  * Made tests faster.
-  * Fixed double disconnect events.
-  * Fixed disconnect logic
-  * Simplified remote events handling in Socket.
-  * Increased testcase timeout.
-  * Fixed unknown room emitting (GH-291). [3rd-Eden]
-  * Fixed `address` in handshakeData. [3rd-Eden]
-  * Removed transports definition in chat example.
-  * Fixed room cleanup
-  * Fixed; make sure the client is cleaned up after booting.
-  * Make sure to mark the client as non-open if the connection is closed.
-  * Removed unneeded `buffer` declarations.
-  * Fixed; make sure to clear socket handlers and subscriptions upon transport close.
-
-0.7.6 / 2011-06-30
-==================
-
-  * Fixed general dispatching when a client has closed.
-
-0.7.5 / 2011-06-30
-==================
-
-  * Fixed dispatching to clients that are disconnected.
-
-0.7.4 / 2011-06-30
-==================
-
-  * Fixed; only clear handlers if they were set. [level09]
-
-0.7.3 / 2011-06-30
-==================
-
-  * Exposed handshake data to clients.
-  * Refactored dispatcher interface.
-  * Changed; Moved id generation method into the manager.
-  * Added sub-namespace authorization. [3rd-Eden]
-  * Changed; normalized SocketNamespace local eventing [dvv]
-  * Changed; Use packet.reason or default to 'packet' [3rd-Eden]
-  * Changed console.error to console.log.
-  * Fixed; bind both servers at the same time do that the test never times out.
-  * Added 304 support.
-  * Removed `Transport#name` for abstract interface.
-  * Changed; lazily require http and https module only when needed. [3rd-Eden]
-
-0.7.2 / 2011-06-22
-==================
-
-  * Make sure to write a packet (of type `noop`) when closing a poll.
-    This solves a problem with cross-domain requests being flagged as aborted and
-    reconnection being triggered.
-  * Added `noop` message type.
-
-0.7.1 / 2011-06-21 
-==================
-
-  * Fixed cross-domain XHR.
-  * Added CORS test to xhr-polling suite.
-
-0.7.0 / 2010-06-21
-==================
-
-  * http://socket.io/announcement.html

LICENSE

@@ -1,6 +1,6 @@
 (The MIT License)
 
-Copyright (c) 2014 Automattic <dev@cloudup.com>
+Copyright (c) 2014-2018 Automattic <dev@cloudup.com>
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

Makefile

@@ -1,15 +0,0 @@
-
-REPORTER = dot
-
-test:
-	@./node_modules/.bin/mocha \
-		--reporter $(REPORTER) \
-		--slow 200ms \
-		--bail
-
-test-cov:
-	@./node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha -- \
-		--reporter $(REPORTER) \
-		test/
-
-.PHONY: test

Readme.md

@@ -1,9 +1,96 @@
-
 # socket.io
+[![Run on Repl.it](https://repl.it/badge/github/socketio/socket.io)](https://repl.it/github/socketio/socket.io)
+[![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)
 
-[![Build Status](https://secure.travis-ci.org/Automattic/socket.io.svg)](http://travis-ci.org/Automattic/socket.io)
-[![NPM version](https://badge.fury.io/js/socket.io.svg)](http://badge.fury.io/js/socket.io)
-![Downloads](http://img.shields.io/npm/dm/socket.io.svg)
+## Features
+
+Socket.IO enables real-time bidirectional event-based communication. It consists of:
+
+- a Node.js server (this repository)
+- a [Javascript client library](https://github.com/socketio/socket.io-client) for the browser (or a Node.js client)
+
+Some implementations in other languages are also available:
+
+- [Java](https://github.com/socketio/socket.io-client-java)
+- [C++](https://github.com/socketio/socket.io-client-cpp)
+- [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)
+
+Its main features are:
+
+#### Reliability
+
+Connections are established even in the presence of:
+  - proxies and load balancers.
+  - personal firewall and antivirus software.
+
+For this purpose, it relies on [Engine.IO](https://github.com/socketio/engine.io), which first establishes a long-polling connection, then tries to upgrade to better transports that are "tested" on the side, like WebSocket. Please see the [Goals](https://github.com/socketio/engine.io#goals) section for more information.
+
+#### Auto-reconnection support
+
+Unless instructed otherwise a disconnected client will try to reconnect forever, until the server is available again. Please see the available reconnection options [here](https://socket.io/docs/v3/client-api/#new-Manager-url-options).
+
+#### Disconnection detection
+
+A heartbeat mechanism is implemented at the Engine.IO level, allowing both the server and the client to know when the other one is not responding anymore.
+
+That functionality is achieved with timers set on both the server and the client, with timeout values (the `pingInterval` and `pingTimeout` parameters) shared during the connection handshake. Those timers require any subsequent client calls to be directed to the same server, hence the `sticky-session` requirement when using multiples nodes.
+
+#### Binary support
+
+Any serializable data structures can be emitted, including:
+
+- [ArrayBuffer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) and [Blob](https://developer.mozilla.org/en-US/docs/Web/API/Blob) in the browser
+- [ArrayBuffer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) and [Buffer](https://nodejs.org/api/buffer.html) in Node.js
+
+#### Simple and convenient API
+
+Sample code:
+
+```js
+io.on('connection', socket => {
+  socket.emit('request', /* … */); // emit an event to the socket
+  io.emit('broadcast', /* … */); // emit an event to all connected sockets
+  socket.on('reply', () => { /* … */ }); // listen to the event
+});
+```
+
+#### Cross-browser
+
+Browser support is tested in Sauce Labs:
+
+[![Sauce Test Status](https://saucelabs.com/browser-matrix/socket.svg)](https://saucelabs.com/u/socket)
+
+#### Multiplexing support
+
+In order to create separation of concerns within your application (for example per module, or based on permissions), Socket.IO allows you to create several `Namespaces`, which will act as separate communication channels but will share the same underlying connection.
+
+#### Room support
+
+Within each `Namespace`, you can define arbitrary channels, called `Rooms`, that sockets can join and leave. You can then broadcast to any given room, reaching every socket that has joined it.
+
+This is a useful feature to send notifications to a group of users, or to a given user connected on several devices for example.
+
+
+**Note:** Socket.IO is not a WebSocket implementation. Although Socket.IO indeed uses WebSocket as a transport when possible, it adds some metadata to each packet: the packet type, the namespace and the ack id when a message acknowledgement is needed. That is why a WebSocket client will not be able to successfully connect to a Socket.IO server, and a Socket.IO client will not be able to connect to a WebSocket server (like `ws://echo.websocket.org`) either. Please see the protocol specification [here](https://github.com/socketio/socket.io-protocol).
+
+## Installation
+
+```bash
+// with npm
+npm install socket.io
+
+// with yarn
+yarn add socket.io
+```
 
 ## How to use
 
@@ -11,11 +98,11 @@ The following example attaches socket.io to a plain Node.JS
 HTTP server listening on port `3000`.
 
 ```js
-var server = require('http').createServer();
-var io = require('socket.io')(server);
-io.on('connection', function(socket){
-  socket.on('event', function(data){});
-  socket.on('disconnect', function(){});
+const server = require('http').createServer();
+const io = require('socket.io')(server);
+io.on('connection', client => {
+  client.on('event', data => { /* … */ });
+  client.on('disconnect', () => { /* … */ });
 });
 server.listen(3000);
 ```
@@ -23,8 +110,8 @@ server.listen(3000);
 ### Standalone
 
 ```js
-var io = require('socket.io')();
-io.on('connection', function(socket){});
+const io = require('socket.io')();
+io.on('connection', client => { ... });
 io.listen(3000);
 ```
 
@@ -33,13 +120,13 @@ io.listen(3000);
 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
-function.
+function. Also make sure to call `.listen` on the `server`, not the `app`.
 
 ```js
-var app = require('express')();
-var server = require('http').createServer(app);
-var io = require('socket.io')(server);
-io.on('connection', function(){ /* … */ });
+const app = require('express')();
+const server = require('http').createServer(app);
+const io = require('socket.io')(server);
+io.on('connection', () => { /* … */ });
 server.listen(3000);
 ```
 
@@ -49,317 +136,35 @@ Like Express.JS, Koa works by exposing an application as a request
 handler function, but only by calling the `callback` method.
 
 ```js
-var app = require('koa')();
-var server = require('http').createServer(app.callback());
-var io = require('socket.io')(server);
-io.on('connection', function(){ /* … */ });
+const app = require('koa')();
+const server = require('http').createServer(app.callback());
+const io = require('socket.io')(server);
+io.on('connection', () => { /* … */ });
 server.listen(3000);
 ```
 
-## API
+### In conjunction with Fastify
 
-### Server
+To integrate Socket.io in your Fastify application you just need to
+register `fastify-socket.io` plugin. It will create a `decorator`
+called `io`.
 
-  Exposed by `require('socket.io')`.
+```js
+const app = require('fastify')();
+app.register(require('fastify-socket.io'));
+app.io.on('connection', () => { /* … */ });
+app.listen(3000);
+```
 
-### Server()
+## Documentation
 
-  Creates a new `Server`. Works with and without `new`:
+Please see the documentation [here](https://socket.io/docs/).
 
-  ```js
-  var io = require('socket.io')();
-  // or
-  var Server = require('socket.io');
-  var io = new Server();
-  ```
-
-### Server(opts:Object)
-
-  Optionally, the first or second argument (see below) of the `Server`
-  constructor can be an options object.
-
-  The following options are supported:
-
-  - `serveClient` sets the value for Server#serveClient()
-  - `path` sets the value for Server#path()
-
-  The same options passed to socket.io are always passed to
-  the `engine.io` `Server` that gets created. See engine.io
-  [options](https://github.com/learnboost/engine.io#methods-1)
-  as reference.
-
-### Server(srv:http#Server, opts:Object)
-
-  Creates a new `Server` and attaches it to the given `srv`. Optionally
-  `opts` can be passed.
-
-### Server(port:Number, opts:Object)
-
-  Binds socket.io to a new `http.Server` that listens on `port`.
-
-### Server#serveClient(v:Boolean):Server
-
-  If `v` is `true` the attached server (see `Server#attach`) will serve
-  the client files. Defaults to `true`.
-
-  This method has no effect after `attach` is called.
-
-  ```js
-  // pass a server and the `serveClient` option
-  var io = require('socket.io')(http, { serveClient: false });
-
-  // or pass no server and then you can call the method
-  var io = require('socket.io')();
-  io.serveClient(false);
-  io.attach(http);
-  ```
-
-  If no arguments are supplied this method returns the current value.
-
-### Server#path(v:String):Server
-
-  Sets the path `v` under which `engine.io` and the static files will be
-  served. Defaults to `/socket.io`.
-
-  If no arguments are supplied this method returns the current value.
-
-### Server#adapter(v:Adapter):Server
-
-  Sets the adapter `v`. Defaults to an instance of the `Adapter` that
-  ships with socket.io which is memory based. See
-  [socket.io-adapter](https://github.com/Automattic/socket.io-adapter).
-
-  If no arguments are supplied this method returns the current value.
-
-### Server#origins(v:String):Server
-
-  Sets the allowed origins `v`. Defaults to any origins being allowed.
-
-  If no arguments are supplied this method returns the current value.
-
-### Server#origins(v:Function):Server
-
-  Sets the allowed origins as dynamic function. Function takes two arguments `origin:String` and `callback(error, success)`, where `success` is a boolean value indicating whether origin is allowed or not.
-
-  __Potential drawbacks__:
-  * in some situations, when it is not possible to determine `origin` it may have value of `*`
-  * As this function will be executed for every request, it is advised to make this function work as fast as possible
-  * If `socket.io` is used together with `Express`, the CORS headers will be affected only for `socket.io` requests. For Express can use [cors](https://github.com/troygoode/node-cors/)
-
-
-### Server#sockets:Namespace
-
-  The default (`/`) namespace.
-
-### Server#attach(srv:http#Server, opts:Object):Server
-
-  Attaches the `Server` to an engine.io instance on `srv` with the
-  supplied `opts` (optionally).
-
-### Server#attach(port:Number, opts:Object):Server
-
-  Attaches the `Server` to an engine.io instance that is bound to `port`
-  with the given `opts` (optionally).
-
-### Server#listen
-
-  Synonym of `Server#attach`.
-
-### Server#bind(srv:engine#Server):Server
-
-  Advanced use only. Binds the server to a specific engine.io `Server`
-  (or compatible API) instance.
-
-### Server#onconnection(socket:engine#Socket):Server
-
-  Advanced use only. Creates a new `socket.io` client from the incoming
-  engine.io (or compatible API) `socket`.
-
-### Server#of(nsp:String):Namespace
-
-  Initializes and retrieves the given `Namespace` by its pathname
-  identifier `nsp`.
-
-  If the namespace was already initialized it returns it right away.
-
-### Server#emit
-
-  Emits an event to all connected clients. The following two are
-  equivalent:
-
-  ```js
-  var io = require('socket.io')();
-  io.sockets.emit('an event sent to all connected clients');
-  io.emit('an event sent to all connected clients');
-  ```
-
-  For other available methods, see `Namespace` below.
-
-### Server#close
-
-  Closes socket server
-
-  ```js
-  var Server = require('socket.io');
-  var PORT   = 3030;
-  var server = require('http').Server();
-
-  var io = Server(PORT);
-
-  io.close(); // Close current server
-
-  server.listen(PORT); // PORT is free to use
-
-  io = Server(server);
-  ```
-
-### Server#use
-
-  See `Namespace#use` below.
-
-### Namespace
-
-  Represents a pool of sockets connected under a given scope identified
-  by a pathname (eg: `/chat`).
-
-  By default the client always connects to `/`.
-
-#### Events
-
-  - `connection` / `connect`. Fired upon a connection.
-
-    Parameters:
-    - `Socket` the incoming socket.
-
-### Namespace#name:String
-
-  The namespace identifier property.
-
-### Namespace#connected:Object<Socket>
-
-  Hash of `Socket` objects that are connected to this namespace indexed
-  by `id`.
-
-### Namespace#use(fn:Function):Namespace
-
-  Registers a middleware, which is a function that gets executed for
-  every incoming `Socket` and receives as parameter the socket and a
-  function to optionally defer execution to the next registered
-  middleware.
-
-  ```js
-  var io = require('socket.io')();
-  io.use(function(socket, next){
-    if (socket.request.headers.cookie) return next();
-    next(new Error('Authentication error'));
-  });
-  ```
-
-  Errors passed to middleware callbacks are sent as special `error`
-  packets to clients.
-
-### Socket
-
-  A `Socket` is the fundamental class for interacting with browser
-  clients. A `Socket` belongs to a certain `Namespace` (by default `/`)
-  and uses an underlying `Client` to communicate.
-
-### Socket#rooms:Array
-
-  A list of strings identifying the rooms this socket is in.
-
-### Socket#client:Client
-
-  A reference to the underlying `Client` object.
-
-### Socket#conn:Socket
-
-  A reference to the underyling `Client` transport connection (engine.io
-  `Socket` object).
-
-### Socket#request:Request
-
-  A getter proxy that returns the reference to the `request` that
-  originated the underlying engine.io `Client`. Useful for accessing
-  request headers such as `Cookie` or `User-Agent`.
-
-### Socket#id:String
-
-  A unique identifier for the socket session, that comes from the
-  underlying `Client`.
-
-### Socket#emit(name:String[, …]):Socket
-
-  Emits an event to the socket identified by the string `name`. Any
-  other parameters can be included.
-
-  All datastructures are supported, including `Buffer`. JavaScript
-  functions can't be serialized/deserialized.
-
-  ```js
-  var io = require('socket.io')();
-  io.on('connection', function(socket){
-    socket.emit('an event', { some: 'data' });
-  });
-  ```
-
-### Socket#join(name:String[, fn:Function]):Socket
-
-  Adds the socket to the `room`, and fires optionally a callback `fn`
-  with `err` signature (if any).
-
-  The socket is automatically a member of a room identified with its
-  session id (see `Socket#id`).
-
-  The mechanics of joining  rooms are handled by the `Adapter`
-  that has been configured (see `Server#adapter` above), defaulting to
-  [socket.io-adapter](https://github.com/Automattic/socket.io-adapter).
-
-### Socket#leave(name:String[, fn:Function]):Socket
-
-  Removes the socket from `room`, and fires optionally a callback `fn`
-  with `err` signature (if any).
-
-  **Rooms are left automatically upon disconnection**.
-
-  The mechanics of leaving rooms are handled by the `Adapter`
-  that has been configured (see `Server#adapter` above), defaulting to
-  [socket.io-adapter](https://github.com/Automattic/socket.io-adapter).
-
-### Socket#to(room:String):Socket
-### Socket#in(room:String):Socket
-
-  Sets a modifier for a subsequent event emission that the event will
-  only be _broadcasted_ to sockets that have joined the given `room`.
-
-  To emit to multiple rooms, you can call `to` several times.
-
-  ```js
-  var io = require('socket.io')();
-  io.on('connection', function(socket){
-    socket.to('others').emit('an event', { some: 'data' });
-  });
-  ```
-
-### Client
-
-  The `Client` class represents an incoming transport (engine.io)
-  connection. A `Client` can be associated with many multiplexed `Socket`
-  that belong to different `Namespace`s.
-
-### Client#conn
-
-  A reference to the underlying `engine.io` `Socket` connection.
-
-### Client#request
-
-  A getter proxy that returns the reference to the `request` that
-  originated the engine.io connection. Useful for accessing
-  request headers such as `Cookie` or `User-Agent`.
+The source code of the website can be found [here](https://github.com/socketio/socket.io-website). Contributions are welcome!
 
 ## Debug / logging
 
-Socket.IO is powered by [debug](http://github.com/visionmedia/debug).
+Socket.IO is powered by [debug](https://github.com/visionmedia/debug).
 In order to see all the debug output, run your app with the environment variable
 `DEBUG` including the desired scope.
 
@@ -369,6 +174,90 @@ To see the output from all of Socket.IO's debugging scopes you can use:
 DEBUG=socket.io* node myapp
 ```
 
+## Testing
+
+```
+npm test
+```
+This runs the `gulp` task `test`. By default the test will be run with the source code in `lib` directory.
+
+Set the environmental variable `TEST_VERSION` to `compat` to test the transpiled es5-compat version of the code.
+
+The `gulp` task `test` will always transpile the source code into es5 and export to `dist` first before running the test.
+
+
+## Backers
+
+Support us with a monthly donation and help us continue our activities. [[Become a backer](https://opencollective.com/socketio#backer)]
+
+<a href="https://opencollective.com/socketio/backer/0/website" target="_blank"><img src="https://opencollective.com/socketio/backer/0/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/1/website" target="_blank"><img src="https://opencollective.com/socketio/backer/1/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/2/website" target="_blank"><img src="https://opencollective.com/socketio/backer/2/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/3/website" target="_blank"><img src="https://opencollective.com/socketio/backer/3/avatar.svg"></a>
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+<a href="https://opencollective.com/socketio/backer/5/website" target="_blank"><img src="https://opencollective.com/socketio/backer/5/avatar.svg"></a>
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+<a href="https://opencollective.com/socketio/backer/13/website" target="_blank"><img src="https://opencollective.com/socketio/backer/13/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/14/website" target="_blank"><img src="https://opencollective.com/socketio/backer/14/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/15/website" target="_blank"><img src="https://opencollective.com/socketio/backer/15/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/16/website" target="_blank"><img src="https://opencollective.com/socketio/backer/16/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/17/website" target="_blank"><img src="https://opencollective.com/socketio/backer/17/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/18/website" target="_blank"><img src="https://opencollective.com/socketio/backer/18/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/19/website" target="_blank"><img src="https://opencollective.com/socketio/backer/19/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/20/website" target="_blank"><img src="https://opencollective.com/socketio/backer/20/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/21/website" target="_blank"><img src="https://opencollective.com/socketio/backer/21/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/22/website" target="_blank"><img src="https://opencollective.com/socketio/backer/22/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/23/website" target="_blank"><img src="https://opencollective.com/socketio/backer/23/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/24/website" target="_blank"><img src="https://opencollective.com/socketio/backer/24/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/25/website" target="_blank"><img src="https://opencollective.com/socketio/backer/25/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/26/website" target="_blank"><img src="https://opencollective.com/socketio/backer/26/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/27/website" target="_blank"><img src="https://opencollective.com/socketio/backer/27/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/28/website" target="_blank"><img src="https://opencollective.com/socketio/backer/28/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/29/website" target="_blank"><img src="https://opencollective.com/socketio/backer/29/avatar.svg"></a>
+
+
+## Sponsors
+
+Become a sponsor and get your logo on our README on Github with a link to your site. [[Become a sponsor](https://opencollective.com/socketio#sponsor)]
+
+<a href="https://opencollective.com/socketio/sponsor/0/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/0/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/1/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/1/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/2/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/2/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/3/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/3/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/4/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/4/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/5/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/5/avatar.svg"></a>
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+<a href="https://opencollective.com/socketio/sponsor/14/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/14/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/15/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/15/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/16/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/16/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/17/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/17/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/18/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/18/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/19/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/19/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/20/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/20/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/21/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/21/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/22/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/22/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/23/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/23/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/24/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/24/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/25/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/25/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/26/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/26/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/27/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/27/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/28/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/28/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/29/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/29/avatar.svg"></a>
+
+
 ## License
 
-MIT
+[MIT](LICENSE)

docs/README.md

@@ -0,0 +1,2 @@
+
+The documentation has been moved to the website [here](https://socket.io/docs/).

examples/angular-todomvc/.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/angular-todomvc/.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/angular-todomvc/.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/angular-todomvc/README.md

@@ -0,0 +1,35 @@
+# 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.
+
+## Socket.IO server
+
+Run `npm run start:server` to start the Socket.IO server.
+
+## 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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/package.json

@@ -0,0 +1,48 @@
+{
+  "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",
+    "start:server": "ts-node -O '{\"module\":\"commonjs\"}' server.ts"
+  },
+  "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": "^3.0.4",
+    "socket.io-client": "^3.0.4",
+    "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/angular-todomvc/server.ts

@@ -0,0 +1,28 @@
+import { Server, Socket } from "socket.io";
+
+const io = new Server(8080, {
+  cors: {
+    origin: "http://localhost:4200",
+    methods: ["GET", "POST"]
+  }
+});
+
+interface Todo {
+  completed: boolean;
+  editing: boolean;
+  title: string;
+}
+
+let todos: Array<Todo> = [];
+
+io.on("connect", (socket: Socket) => {
+    socket.emit("todos", todos);
+
+    // note: we could also create a CRUD (create/read/update/delete) service for the todo list
+    socket.on("update-store", (updatedTodos) => {
+      // store it locally
+      todos = updatedTodos;
+      // broadcast to everyone but the sender
+      socket.broadcast.emit("todos", todos);
+    });
+});

examples/angular-todomvc/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/angular-todomvc/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/angular-todomvc/src/app/app.component.ts

@@ -0,0 +1,59 @@
+import { Component } from '@angular/core';
+import { RemoteTodoStore, Todo } from './store';
+
+@Component({
+  selector: 'app-root',
+  templateUrl: './app.component.html',
+  styleUrls: ['./app.component.css']
+})
+export class AppComponent {
+  todoStore: RemoteTodoStore;
+  newTodoText = '';
+
+  constructor(todoStore: RemoteTodoStore) {
+    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/angular-todomvc/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 { RemoteTodoStore } from './store';
+import { FormsModule } from "@angular/forms";
+
+@NgModule({
+  declarations: [
+    AppComponent
+  ],
+  imports: [
+    BrowserModule,
+    FormsModule
+  ],
+  providers: [RemoteTodoStore],
+  bootstrap: [AppComponent]
+})
+export class AppModule { }

examples/angular-todomvc/src/app/store.ts

@@ -0,0 +1,95 @@
+import { io, Socket } from "socket.io-client";
+
+export class Todo {
+  completed: boolean;
+  editing: boolean;
+
+  private _title: String = "";
+  get title() {
+    return this._title;
+  }
+  set title(value: String) {
+    this._title = value.trim();
+  }
+
+  constructor(title: String) {
+    this.completed = false;
+    this.editing = false;
+    this.title = title.trim();
+  }
+}
+
+export class TodoStore {
+  todos: Array<Todo>;
+
+  constructor() {
+    let persistedTodos = JSON.parse(localStorage.getItem('angular2-todos') || '[]');
+    // Normalize back into classes
+    this.todos = persistedTodos.map( (todo: {_title: String, completed: boolean}) => {
+      let ret = new Todo(todo._title);
+      ret.completed = todo.completed;
+      return ret;
+    });
+  }
+
+  protected updateStore() {
+    localStorage.setItem('angular2-todos', JSON.stringify(this.todos));
+  }
+
+  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((t: Todo) => t.completed = completed);
+    this.updateStore();
+  }
+
+  removeCompleted() {
+    this.todos = this.getWithCompleted(false);
+    this.updateStore();
+  }
+
+  getRemaining() {
+    return this.getWithCompleted(false);
+  }
+
+  getCompleted() {
+    return this.getWithCompleted(true);
+  }
+
+  toggleCompletion(todo: Todo) {
+    todo.completed = !todo.completed;
+    this.updateStore();
+  }
+
+  remove(todo: Todo) {
+    this.todos.splice(this.todos.indexOf(todo), 1);
+    this.updateStore();
+  }
+
+  add(title: String) {
+    this.todos.push(new Todo(title));
+    this.updateStore();
+  }
+}
+
+export class RemoteTodoStore extends TodoStore {
+  private socket: Socket;
+
+  constructor() {
+    super();
+    this.socket = io("http://localhost:8080");
+    this.socket.on("todos", (updatedTodos: Array<Todo>) => {
+      this.todos = updatedTodos;
+    });
+  }
+
+  protected updateStore() {
+    this.socket.emit("update-store", this.todos.map(({ title, editing, completed }) => ({ title, editing, completed })));
+  }
+}

examples/angular-todomvc/src/environments/environment.prod.ts

@@ -0,0 +1,3 @@
+export const environment = {
+  production: true
+};

examples/angular-todomvc/src/environments/environment.ts

@@ -0,0 +1,16 @@
+// 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
+};
+
+/*
+ * 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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/angular-todomvc/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/chat/README.md

@@ -1,16 +1,13 @@
 
 # Socket.IO Chat
 
-A simple chat demo for socket.io
+A simple chat demo for Socket.IO
 
 ## How to use
 
 ```
-$ cd socket.io
-$ npm install
-$ cd examples/chat
-$ npm install
-$ node .
+$ npm ci
+$ npm start
 ```
 
 And point your browser to `http://localhost:3000`. Optionally, specify

examples/chat/index.js

@@ -1,28 +1,27 @@
 // Setup basic express server
-var express = require('express');
-var app = express();
-var server = require('http').createServer(app);
-var io = require('../..')(server);
-var port = process.env.PORT || 3000;
+const express = require('express');
+const app = express();
+const path = require('path');
+const server = require('http').createServer(app);
+const io = require('socket.io')(server);
+const port = process.env.PORT || 3000;
 
-server.listen(port, function () {
+server.listen(port, () => {
   console.log('Server listening at port %d', port);
 });
 
 // Routing
-app.use(express.static(__dirname + '/public'));
+app.use(express.static(path.join(__dirname, 'public')));
 
 // Chatroom
 
-// usernames which are currently connected to the chat
-var usernames = {};
-var numUsers = 0;
+let numUsers = 0;
 
-io.on('connection', function (socket) {
-  var addedUser = false;
+io.on('connection', (socket) => {
+  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,
@@ -31,11 +30,11 @@ 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
     socket.username = username;
-    // add the client's username to the global list
-    usernames[username] = username;
     ++numUsers;
     addedUser = true;
     socket.emit('login', {
@@ -49,24 +48,22 @@ 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 () {
-    // remove the username from global usernames list
+  socket.on('disconnect', () => {
     if (addedUser) {
-      delete usernames[socket.username];
       --numUsers;
 
       // echo globally that this client has left

examples/chat/package-lock.json

@@ -0,0 +1,499 @@
+{
+  "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"
+      }
+    },
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+      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
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+        "ms": "2.0.0"
+      }
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+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/depd/-/depd-1.1.2.tgz",
+      "integrity": "sha1-m81S4UwJd2PnSbJ0xDRu0uVgtak="
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+      "integrity": "sha1-l4hXRCxEdJ5CBmE+N5RiBYJqvYA="
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+      "integrity": "sha1-rT/0yG7C0CkyL1oCw6mmBslbP1k="
+    },
+    "engine.io": {
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+      "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=="
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+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
+          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
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+    }
+  }
+}

examples/chat/package.json

@@ -7,6 +7,10 @@
   "private": true,
   "license": "BSD",
   "dependencies": {
-    "express": "3.4.8"
+    "express": "~4.17.1",
+    "socket.io": "^3.0.0"
+  },
+  "scripts": {
+    "start": "node index.js"
   }
-}
+}

examples/chat/public/main.js

@@ -1,42 +1,42 @@
 $(function() {
-  var FADE_TIME = 150; // ms
-  var TYPING_TIMER_LENGTH = 400; // ms
-  var COLORS = [
+  const FADE_TIME = 150; // ms
+  const TYPING_TIMER_LENGTH = 400; // ms
+  const COLORS = [
     '#e21400', '#91580f', '#f8a700', '#f78b00',
     '#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
     '#3b88eb', '#3824aa', '#a700ff', '#d300e7'
   ];
 
-  // Initialize varibles
-  var $window = $(window);
-  var $usernameInput = $('.usernameInput'); // Input for username
-  var $messages = $('.messages'); // Messages area
-  var $inputMessage = $('.inputMessage'); // Input message input box
+  // Initialize variables
+  const $window = $(window);
+  const $usernameInput = $('.usernameInput'); // Input for username
+  const $messages = $('.messages');           // Messages area
+  const $inputMessage = $('.inputMessage');   // Input message input box
 
-  var $loginPage = $('.login.page'); // The login page
-  var $chatPage = $('.chat.page'); // The chatroom page
+  const $loginPage = $('.login.page');        // The login page
+  const $chatPage = $('.chat.page');          // The chatroom page
+
+  const socket = io();
 
   // Prompt for setting a username
-  var username;
-  var connected = false;
-  var typing = false;
-  var lastTypingTime;
-  var $currentInput = $usernameInput.focus();
+  let username;
+  let connected = false;
+  let typing = false;
+  let lastTypingTime;
+  let $currentInput = $usernameInput.focus();
 
-  var socket = io();
-
-  function addParticipantsMessage (data) {
-    var message = '';
+  const addParticipantsMessage = (data) => {
+    let message = '';
     if (data.numUsers === 1) {
-      message += "there's 1 participant";
+      message += `there's 1 participant`;
     } else {
-      message += "there are " + data.numUsers + " participants";
+      message += `there are ${data.numUsers} participants`;
     }
     log(message);
   }
 
   // Sets the client's username
-  function setUsername () {
+  const setUsername = () => {
     username = cleanInput($usernameInput.val().trim());
 
     // If the username is valid
@@ -52,46 +52,42 @@ $(function() {
   }
 
   // Sends a chat message
-  function sendMessage () {
-    var message = $inputMessage.val();
+  const sendMessage = () => {
+    let message = $inputMessage.val();
     // Prevent markup from being injected into the message
     message = cleanInput(message);
     // if there is a non-empty message and a socket connection
     if (message && connected) {
       $inputMessage.val('');
-      addChatMessage({
-        username: username,
-        message: message
-      });
+      addChatMessage({ username, message });
       // tell server to execute 'new message' and send along one parameter
       socket.emit('new message', message);
     }
   }
 
   // Log a message
-  function log (message, options) {
-    var $el = $('<li>').addClass('log').text(message);
+  const log = (message, options) => {
+    const $el = $('<li>').addClass('log').text(message);
     addMessageElement($el, options);
   }
 
   // Adds the visual chat message to the message list
-  function addChatMessage (data, options) {
+  const addChatMessage = (data, options) => {
     // Don't fade the message in if there is an 'X was typing'
-    var $typingMessages = getTypingMessages(data);
-    options = options || {};
+    const $typingMessages = getTypingMessages(data);
     if ($typingMessages.length !== 0) {
       options.fade = false;
       $typingMessages.remove();
     }
 
-    var $usernameDiv = $('<span class="username"/>')
+    const $usernameDiv = $('<span class="username"/>')
       .text(data.username)
       .css('color', getUsernameColor(data.username));
-    var $messageBodyDiv = $('<span class="messageBody">')
+    const $messageBodyDiv = $('<span class="messageBody">')
       .text(data.message);
 
-    var typingClass = data.typing ? 'typing' : '';
-    var $messageDiv = $('<li class="message"/>')
+    const typingClass = data.typing ? 'typing' : '';
+    const $messageDiv = $('<li class="message"/>')
       .data('username', data.username)
       .addClass(typingClass)
       .append($usernameDiv, $messageBodyDiv);
@@ -100,14 +96,14 @@ $(function() {
   }
 
   // Adds the visual chat typing message
-  function addChatTyping (data) {
+  const addChatTyping = (data) => {
     data.typing = true;
     data.message = 'is typing';
     addChatMessage(data);
   }
 
   // Removes the visual chat typing message
-  function removeChatTyping (data) {
+  const removeChatTyping = (data) => {
     getTypingMessages(data).fadeOut(function () {
       $(this).remove();
     });
@@ -118,9 +114,8 @@ $(function() {
   // options.fade - If the element should fade-in (default = true)
   // options.prepend - If the element should prepend
   //   all other messages (default = false)
-  function addMessageElement (el, options) {
-    var $el = $(el);
-
+  const addMessageElement = (el, options) => {
+    const $el = $(el);
     // Setup default options
     if (!options) {
       options = {};
@@ -141,16 +136,17 @@ $(function() {
     } else {
       $messages.append($el);
     }
+
     $messages[0].scrollTop = $messages[0].scrollHeight;
   }
 
   // Prevents input from having injected markup
-  function cleanInput (input) {
-    return $('<div/>').text(input).text();
+  const cleanInput = (input) => {
+    return $('<div/>').text(input).html();
   }
 
   // Updates the typing event
-  function updateTyping () {
+  const updateTyping = () => {
     if (connected) {
       if (!typing) {
         typing = true;
@@ -158,9 +154,9 @@ $(function() {
       }
       lastTypingTime = (new Date()).getTime();
 
-      setTimeout(function () {
-        var typingTimer = (new Date()).getTime();
-        var timeDiff = typingTimer - lastTypingTime;
+      setTimeout(() => {
+        const typingTimer = (new Date()).getTime();
+        const timeDiff = typingTimer - lastTypingTime;
         if (timeDiff >= TYPING_TIMER_LENGTH && typing) {
           socket.emit('stop typing');
           typing = false;
@@ -170,27 +166,27 @@ $(function() {
   }
 
   // Gets the 'X is typing' messages of a user
-  function getTypingMessages (data) {
+  const getTypingMessages = (data) => {
     return $('.typing.message').filter(function (i) {
       return $(this).data('username') === data.username;
     });
   }
 
   // Gets the color of a username through our hash function
-  function getUsernameColor (username) {
+  const getUsernameColor = (username) => {
     // Compute hash code
-    var hash = 7;
-    for (var i = 0; i < username.length; i++) {
-       hash = username.charCodeAt(i) + (hash << 5) - hash;
+    let hash = 7;
+    for (let i = 0; i < username.length; i++) {
+      hash = username.charCodeAt(i) + (hash << 5) - hash;
     }
     // Calculate color
-    var index = Math.abs(hash % COLORS.length);
+    const index = Math.abs(hash % COLORS.length);
     return COLORS[index];
   }
 
   // Keyboard events
 
-  $window.keydown(function (event) {
+  $window.keydown(event => {
     // Auto-focus the current input when a key is typed
     if (!(event.ctrlKey || event.metaKey || event.altKey)) {
       $currentInput.focus();
@@ -207,29 +203,29 @@ $(function() {
     }
   });
 
-  $inputMessage.on('input', function() {
+  $inputMessage.on('input', () => {
     updateTyping();
   });
 
   // Click events
 
   // Focus input when clicking anywhere on login page
-  $loginPage.click(function () {
+  $loginPage.click(() => {
     $currentInput.focus();
   });
 
   // Focus input when clicking on the message input's border
-  $inputMessage.click(function () {
+  $inputMessage.click(() => {
     $inputMessage.focus();
   });
 
   // Socket events
 
   // Whenever the server emits 'login', log the login message
-  socket.on('login', function (data) {
+  socket.on('login', (data) => {
     connected = true;
     // Display the welcome message
-    var message = "Welcome to Socket.IO Chat – ";
+    const message = 'Welcome to Socket.IO Chat – ';
     log(message, {
       prepend: true
     });
@@ -237,30 +233,46 @@ $(function() {
   });
 
   // Whenever the server emits 'new message', update the chat body
-  socket.on('new message', function (data) {
+  socket.on('new message', (data) => {
     addChatMessage(data);
   });
 
   // Whenever the server emits 'user joined', log it in the chat body
-  socket.on('user joined', function (data) {
-    log(data.username + ' joined');
+  socket.on('user joined', (data) => {
+    log(`${data.username} joined`);
     addParticipantsMessage(data);
   });
 
   // Whenever the server emits 'user left', log it in the chat body
-  socket.on('user left', function (data) {
-    log(data.username + ' left');
+  socket.on('user left', (data) => {
+    log(`${data.username} left`);
     addParticipantsMessage(data);
     removeChatTyping(data);
   });
 
   // Whenever the server emits 'typing', show the typing message
-  socket.on('typing', function (data) {
+  socket.on('typing', (data) => {
     addChatTyping(data);
   });
 
   // Whenever the server emits 'stop typing', kill the typing message
-  socket.on('stop typing', function (data) {
+  socket.on('stop typing', (data) => {
     removeChatTyping(data);
   });
+
+  socket.on('disconnect', () => {
+    log('you have been disconnected');
+  });
+
+  socket.on('reconnect', () => {
+    log('you have been reconnected');
+    if (username) {
+      socket.emit('add user', username);
+    }
+  });
+
+  socket.on('reconnect_error', () => {
+    log('attempt to reconnect has failed');
+  });
+
 });

examples/chat/public/style.css

@@ -128,7 +128,6 @@ ul {
 }
 
 .username {
-  float: left;
   font-weight: 700;
   overflow: hidden;
   padding-right: 15px;

examples/cluster-haproxy/README.md

@@ -0,0 +1,31 @@
+
+# Socket.IO Chat with haproxy & redis
+
+A simple chat demo for socket.io
+
+## How to use
+
+Install [Docker Compose](https://docs.docker.com/compose/install/), then:
+
+```
+$ docker-compose up -d
+```
+
+And then point your browser to `http://localhost:3000`.
+
+This will start four Socket.IO nodes, behind a haproxy instance which will loadbalance the requests (using a cookie for sticky sessions, see [cookie](https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#4.2-cookie)).
+
+Each node connects to the redis backend, which will enable to broadcast to every client, no matter which node it is currently connected to.
+
+```
+# you can kill a given node, the client should reconnect to another node
+$ docker-compose stop server-george
+```
+
+## Features
+
+- Multiple users can join a chat room by each entering a unique username
+on website load.
+- Users can type chat messages to the chat room.
+- A notification is sent to all users when a user joins or leaves
+the chatroom.

examples/cluster-haproxy/docker-compose.yml

@@ -0,0 +1,51 @@
+
+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-paul:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Paul
+
+server-george:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=George
+
+server-ringo:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Ringo
+
+redis:
+  image: redis:alpine
+  expose:
+    - "6379"

examples/cluster-haproxy/haproxy/Dockerfile

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

examples/cluster-haproxy/haproxy/haproxy.cfg

@@ -0,0 +1,31 @@
+# Reference: http://blog.haproxy.com/2012/11/07/websockets-load-balancing-with-haproxy/
+
+global
+  daemon
+  maxconn 4096
+  nbproc 2
+
+defaults
+  mode http
+  balance roundrobin
+  option http-server-close
+  timeout connect     5s
+  timeout client      30s
+  timeout client-fin  30s
+  timeout server      30s
+  timeout tunnel      1h
+  default-server inter 1s rise 2 fall 1 on-marked-down shutdown-sessions
+  option forwardfor
+
+listen chat
+  bind *:80
+  default_backend nodes
+
+backend nodes
+  option httpchk HEAD /health
+  http-check expect status 200
+  cookie serverid insert
+  server john    server-john:3000    cookie john   check
+  server paul    server-paul:3000    cookie paul   check
+  server george  server-george:3000  cookie george check
+  server ringo   server-ringo:3000   cookie ringo  check

examples/cluster-haproxy/server/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:14-alpine
+
+# Create app directory
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Install app dependencies
+COPY package.json /usr/src/app/
+RUN npm install --prod
+
+# Bundle app source
+COPY . /usr/src/app
+
+EXPOSE 3000
+CMD [ "npm", "start" ]

examples/cluster-haproxy/server/index.js

@@ -0,0 +1,87 @@
+// 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';
+
+io.adapter(redis({ host: 'redis', port: 6379 }));
+
+server.listen(port, function () {
+  console.log('Server listening at port %d', port);
+  console.log('Hello, I\'m %s, how can I help?', serverName);
+});
+
+// Routing
+app.use(express.static(__dirname + '/public'));
+
+// Health check
+app.head('/health', function (req, res) {
+  res.sendStatus(200);
+});
+
+// Chatroom
+
+var numUsers = 0;
+
+io.on('connection', function (socket) {
+  socket.emit('my-name-is', serverName);
+
+  var addedUser = false;
+
+  // when the client emits 'new message', this listens and executes
+  socket.on('new message', function (data) {
+    // we tell the client to execute 'new message'
+    socket.broadcast.emit('new message', {
+      username: socket.username,
+      message: data
+    });
+  });
+
+  // when the client emits 'add user', this listens and executes
+  socket.on('add user', function (username) {
+    if (addedUser) return;
+
+    // we store the username in the socket session for this client
+    socket.username = username;
+    ++numUsers;
+    addedUser = true;
+    socket.emit('login', {
+      numUsers: numUsers
+    });
+    // echo globally (all clients) that a person has connected
+    socket.broadcast.emit('user joined', {
+      username: socket.username,
+      numUsers: numUsers
+    });
+  });
+
+  // when the client emits 'typing', we broadcast it to others
+  socket.on('typing', function () {
+    socket.broadcast.emit('typing', {
+      username: socket.username
+    });
+  });
+
+  // when the client emits 'stop typing', we broadcast it to others
+  socket.on('stop typing', function () {
+    socket.broadcast.emit('stop typing', {
+      username: socket.username
+    });
+  });
+
+  // when the user disconnects.. perform this
+  socket.on('disconnect', function () {
+    if (addedUser) {
+      --numUsers;
+
+      // echo globally that this client has left
+      socket.broadcast.emit('user left', {
+        username: socket.username,
+        numUsers: numUsers
+      });
+    }
+  });
+});

examples/cluster-haproxy/server/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "socket.io-chat",
+  "version": "0.0.0",
+  "description": "A simple chat client using socket.io",
+  "main": "index.js",
+  "author": "Grant Timmerman",
+  "private": true,
+  "license": "BSD",
+  "dependencies": {
+    "express": "4.13.4",
+    "socket.io": "^3.1.0",
+    "socket.io-redis": "^6.0.1"
+  },
+  "scripts": {
+    "start": "node index.js"
+  }
+}

examples/cluster-haproxy/server/public/index.html

@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Socket.IO Chat Example</title>
+  <link rel="stylesheet" href="style.css">
+</head>
+<body>
+  <ul class="pages">
+    <li class="chat page">
+      <div class="chatArea">
+        <ul class="messages"></ul>
+      </div>
+      <input class="inputMessage" placeholder="Type here..."/>
+    </li>
+    <li class="login page">
+      <div class="form">
+        <h3 class="title">What's your nickname?</h3>
+        <input class="usernameInput" type="text" maxlength="14" />
+      </div>
+    </li>
+  </ul>
+
+  <script src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
+  <script src="/socket.io/socket.io.js"></script>
+  <script src="/main.js"></script>
+</body>
+</html>

examples/cluster-haproxy/server/public/main.js

@@ -0,0 +1,286 @@
+$(function() {
+  var FADE_TIME = 150; // ms
+  var TYPING_TIMER_LENGTH = 400; // ms
+  var COLORS = [
+    '#e21400', '#91580f', '#f8a700', '#f78b00',
+    '#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
+    '#3b88eb', '#3824aa', '#a700ff', '#d300e7'
+  ];
+
+  // Initialize variables
+  var $window = $(window);
+  var $usernameInput = $('.usernameInput'); // Input for username
+  var $messages = $('.messages'); // Messages area
+  var $inputMessage = $('.inputMessage'); // Input message input box
+
+  var $loginPage = $('.login.page'); // The login page
+  var $chatPage = $('.chat.page'); // The chatroom page
+
+  // Prompt for setting a username
+  var username;
+  var connected = false;
+  var typing = false;
+  var lastTypingTime;
+  var $currentInput = $usernameInput.focus();
+
+  var socket = io();
+
+  function addParticipantsMessage (data) {
+    var message = '';
+    if (data.numUsers === 1) {
+      message += "there's 1 participant";
+    } else {
+      message += "there are " + data.numUsers + " participants";
+    }
+    log(message);
+  }
+
+  // Sets the client's username
+  function setUsername () {
+    username = cleanInput($usernameInput.val().trim());
+
+    // If the username is valid
+    if (username) {
+      $loginPage.fadeOut();
+      $chatPage.show();
+      $loginPage.off('click');
+      $currentInput = $inputMessage.focus();
+
+      // Tell the server your username
+      socket.emit('add user', username);
+    }
+  }
+
+  // Sends a chat message
+  function sendMessage () {
+    var message = $inputMessage.val();
+    // Prevent markup from being injected into the message
+    message = cleanInput(message);
+    // if there is a non-empty message and a socket connection
+    if (message && connected) {
+      $inputMessage.val('');
+      addChatMessage({
+        username: username,
+        message: message
+      });
+      // tell server to execute 'new message' and send along one parameter
+      socket.emit('new message', message);
+    }
+  }
+
+  // Log a message
+  function log (message, options) {
+    var $el = $('<li>').addClass('log').text(message);
+    addMessageElement($el, options);
+  }
+
+  // Adds the visual chat message to the message list
+  function addChatMessage (data, options) {
+    // Don't fade the message in if there is an 'X was typing'
+    var $typingMessages = getTypingMessages(data);
+    options = options || {};
+    if ($typingMessages.length !== 0) {
+      options.fade = false;
+      $typingMessages.remove();
+    }
+
+    var $usernameDiv = $('<span class="username"/>')
+      .text(data.username)
+      .css('color', getUsernameColor(data.username));
+    var $messageBodyDiv = $('<span class="messageBody">')
+      .text(data.message);
+
+    var typingClass = data.typing ? 'typing' : '';
+    var $messageDiv = $('<li class="message"/>')
+      .data('username', data.username)
+      .addClass(typingClass)
+      .append($usernameDiv, $messageBodyDiv);
+
+    addMessageElement($messageDiv, options);
+  }
+
+  // Adds the visual chat typing message
+  function addChatTyping (data) {
+    data.typing = true;
+    data.message = 'is typing';
+    addChatMessage(data);
+  }
+
+  // Removes the visual chat typing message
+  function removeChatTyping (data) {
+    getTypingMessages(data).fadeOut(function () {
+      $(this).remove();
+    });
+  }
+
+  // Adds a message element to the messages and scrolls to the bottom
+  // el - The element to add as a message
+  // options.fade - If the element should fade-in (default = true)
+  // options.prepend - If the element should prepend
+  //   all other messages (default = false)
+  function addMessageElement (el, options) {
+    var $el = $(el);
+
+    // Setup default options
+    if (!options) {
+      options = {};
+    }
+    if (typeof options.fade === 'undefined') {
+      options.fade = true;
+    }
+    if (typeof options.prepend === 'undefined') {
+      options.prepend = false;
+    }
+
+    // Apply options
+    if (options.fade) {
+      $el.hide().fadeIn(FADE_TIME);
+    }
+    if (options.prepend) {
+      $messages.prepend($el);
+    } else {
+      $messages.append($el);
+    }
+    $messages[0].scrollTop = $messages[0].scrollHeight;
+  }
+
+  // Prevents input from having injected markup
+  function cleanInput (input) {
+    return $('<div/>').text(input).text();
+  }
+
+  // Updates the typing event
+  function updateTyping () {
+    if (connected) {
+      if (!typing) {
+        typing = true;
+        socket.emit('typing');
+      }
+      lastTypingTime = (new Date()).getTime();
+
+      setTimeout(function () {
+        var typingTimer = (new Date()).getTime();
+        var timeDiff = typingTimer - lastTypingTime;
+        if (timeDiff >= TYPING_TIMER_LENGTH && typing) {
+          socket.emit('stop typing');
+          typing = false;
+        }
+      }, TYPING_TIMER_LENGTH);
+    }
+  }
+
+  // Gets the 'X is typing' messages of a user
+  function getTypingMessages (data) {
+    return $('.typing.message').filter(function (i) {
+      return $(this).data('username') === data.username;
+    });
+  }
+
+  // Gets the color of a username through our hash function
+  function getUsernameColor (username) {
+    // Compute hash code
+    var hash = 7;
+    for (var i = 0; i < username.length; i++) {
+       hash = username.charCodeAt(i) + (hash << 5) - hash;
+    }
+    // Calculate color
+    var index = Math.abs(hash % COLORS.length);
+    return COLORS[index];
+  }
+
+  // Keyboard events
+
+  $window.keydown(function (event) {
+    // Auto-focus the current input when a key is typed
+    if (!(event.ctrlKey || event.metaKey || event.altKey)) {
+      $currentInput.focus();
+    }
+    // When the client hits ENTER on their keyboard
+    if (event.which === 13) {
+      if (username) {
+        sendMessage();
+        socket.emit('stop typing');
+        typing = false;
+      } else {
+        setUsername();
+      }
+    }
+  });
+
+  $inputMessage.on('input', function() {
+    updateTyping();
+  });
+
+  // Click events
+
+  // Focus input when clicking anywhere on login page
+  $loginPage.click(function () {
+    $currentInput.focus();
+  });
+
+  // Focus input when clicking on the message input's border
+  $inputMessage.click(function () {
+    $inputMessage.focus();
+  });
+
+  // Socket events
+
+  // Whenever the server emits 'login', log the login message
+  socket.on('login', function (data) {
+    connected = true;
+    // Display the welcome message
+    var message = "Welcome to Socket.IO Chat – ";
+    log(message, {
+      prepend: true
+    });
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'new message', update the chat body
+  socket.on('new message', function (data) {
+    addChatMessage(data);
+  });
+
+  // Whenever the server emits 'user joined', log it in the chat body
+  socket.on('user joined', function (data) {
+    log(data.username + ' joined');
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'user left', log it in the chat body
+  socket.on('user left', function (data) {
+    log(data.username + ' left');
+    addParticipantsMessage(data);
+    removeChatTyping(data);
+  });
+
+  // Whenever the server emits 'typing', show the typing message
+  socket.on('typing', function (data) {
+    addChatTyping(data);
+  });
+
+  // Whenever the server emits 'stop typing', kill the typing message
+  socket.on('stop typing', function (data) {
+    removeChatTyping(data);
+  });
+
+  socket.on('disconnect', function () {
+    log('you have been disconnected');
+  });
+
+  socket.on('reconnect', function () {
+    log('you have been reconnected');
+    if (username) {
+      socket.emit('add user', username);
+    }
+  });
+
+  socket.on('reconnect_error', function () {
+    log('attempt to reconnect has failed');
+  });
+
+  socket.on('my-name-is', function (serverName) {
+    log('host is now ' + serverName);
+  })
+
+});

examples/cluster-haproxy/server/public/style.css

@@ -0,0 +1,149 @@
+/* Fix user-agent */
+
+* {
+  box-sizing: border-box;
+}
+
+html {
+  font-weight: 300;
+  -webkit-font-smoothing: antialiased;
+}
+
+html, input {
+  font-family:
+    "HelveticaNeue-Light",
+    "Helvetica Neue Light",
+    "Helvetica Neue",
+    Helvetica,
+    Arial,
+    "Lucida Grande",
+    sans-serif;
+}
+
+html, body {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+}
+
+ul {
+  list-style: none;
+  word-wrap: break-word;
+}
+
+/* Pages */
+
+.pages {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+  width: 100%;
+}
+
+.page {
+  height: 100%;
+  position: absolute;
+  width: 100%;
+}
+
+/* Login Page */
+
+.login.page {
+  background-color: #000;
+}
+
+.login.page .form {
+  height: 100px;
+  margin-top: -100px;
+  position: absolute;
+
+  text-align: center;
+  top: 50%;
+  width: 100%;
+}
+
+.login.page .form .usernameInput {
+  background-color: transparent;
+  border: none;
+  border-bottom: 2px solid #fff;
+  outline: none;
+  padding-bottom: 15px;
+  text-align: center;
+  width: 400px;
+}
+
+.login.page .title {
+  font-size: 200%;
+}
+
+.login.page .usernameInput {
+  font-size: 200%;
+  letter-spacing: 3px;
+}
+
+.login.page .title, .login.page .usernameInput {
+  color: #fff;
+  font-weight: 100;
+}
+
+/* Chat page */
+
+.chat.page {
+  display: none;
+}
+
+/* Font */
+
+.messages {
+  font-size: 150%;
+}
+
+.inputMessage {
+  font-size: 100%;
+}
+
+.log {
+  color: gray;
+  font-size: 70%;
+  margin: 5px;
+  text-align: center;
+}
+
+/* Messages */
+
+.chatArea {
+  height: 100%;
+  padding-bottom: 60px;
+}
+
+.messages {
+  height: 100%;
+  margin: 0;
+  overflow-y: scroll;
+  padding: 10px 20px 10px 20px;
+}
+
+.message.typing .messageBody {
+  color: gray;
+}
+
+.username {
+  font-weight: 700;
+  overflow: hidden;
+  padding-right: 15px;
+  text-align: right;
+}
+
+/* Input */
+
+.inputMessage {
+  border: 10px solid #000;
+  bottom: 0;
+  height: 60px;
+  left: 0;
+  outline: none;
+  padding-left: 10px;
+  position: absolute;
+  right: 0;
+  width: 100%;
+}

examples/cluster-httpd/README.md

@@ -0,0 +1,31 @@
+
+# Socket.IO Chat with httpd & redis
+
+A simple chat demo for socket.io
+
+## How to use
+
+Install [Docker Compose](https://docs.docker.com/compose/install/), then:
+
+```
+$ docker-compose up -d
+```
+
+And then point your browser to `http://localhost:3000`.
+
+This will start four Socket.IO nodes, behind a httpd proxy which will loadbalance the requests (using a cookie for sticky sessions, see [cookie](http://httpd.apache.org/docs/2.4/fr/mod/mod_proxy_balancer.html)).
+
+Each node connects to the redis backend, which will enable to broadcast to every client, no matter which node it is currently connected to.
+
+```
+# you can kill a given node, the client should reconnect to another node
+$ docker-compose stop server-george
+```
+
+## Features
+
+- Multiple users can join a chat room by each entering a unique username
+on website load.
+- Users can type chat messages to the chat room.
+- A notification is sent to all users when a user joins or leaves
+the chatroom.

examples/cluster-httpd/docker-compose.yml

@@ -0,0 +1,51 @@
+
+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-paul:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Paul
+
+server-george:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=George
+
+server-ringo:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Ringo
+
+redis:
+  image: redis:alpine
+  expose:
+    - "6379"

examples/cluster-httpd/httpd/Dockerfile

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

examples/cluster-httpd/httpd/httpd.conf

@@ -0,0 +1,54 @@
+
+Listen 80
+
+ServerName localhost
+
+LoadModule mpm_event_module             modules/mod_mpm_event.so
+
+LoadModule authn_file_module            modules/mod_authn_file.so
+LoadModule authn_core_module            modules/mod_authn_core.so
+LoadModule authz_host_module            modules/mod_authz_host.so
+LoadModule authz_groupfile_module       modules/mod_authz_groupfile.so
+LoadModule authz_user_module            modules/mod_authz_user.so
+LoadModule authz_core_module            modules/mod_authz_core.so
+
+LoadModule headers_module               modules/mod_headers.so
+LoadModule lbmethod_byrequests_module   modules/mod_lbmethod_byrequests.so
+LoadModule proxy_module                 modules/mod_proxy.so
+LoadModule proxy_balancer_module        modules/mod_proxy_balancer.so
+LoadModule proxy_http_module            modules/mod_proxy_http.so
+LoadModule proxy_wstunnel_module        modules/mod_proxy_wstunnel.so
+LoadModule rewrite_module               modules/mod_rewrite.so
+LoadModule slotmem_shm_module           modules/mod_slotmem_shm.so
+LoadModule unixd_module                 modules/mod_unixd.so
+
+User daemon
+Group daemon
+
+ErrorLog /proc/self/fd/2
+
+Header add Set-Cookie "SERVERID=sticky.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED
+
+<Proxy "balancer://nodes_polling">
+    BalancerMember "http://server-john:3000"    route=john
+    BalancerMember "http://server-paul:3000"    route=paul
+    BalancerMember "http://server-george:3000"  route=george
+    BalancerMember "http://server-ringo:3000"   route=ringo
+    ProxySet stickysession=SERVERID
+</Proxy>
+
+<Proxy "balancer://nodes_ws">
+    BalancerMember "ws://server-john:3000"    route=john
+    BalancerMember "ws://server-paul:3000"    route=paul
+    BalancerMember "ws://server-george:3000"  route=george
+    BalancerMember "ws://server-ringo:3000"   route=ringo
+    ProxySet stickysession=SERVERID
+</Proxy>
+
+RewriteEngine On
+RewriteCond %{HTTP:Upgrade} =websocket [NC]
+RewriteRule /(.*) balancer://nodes_ws/$1 [P,L]
+RewriteCond %{HTTP:Upgrade} !=websocket [NC]
+RewriteRule /(.*) balancer://nodes_polling/$1 [P,L]
+
+ProxyTimeout 3

examples/cluster-httpd/server/Dockerfile

@@ -0,0 +1,15 @@
+FROM mhart/alpine-node:6
+
+# Create app directory
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Install app dependencies
+COPY package.json /usr/src/app/
+RUN npm install --prod
+
+# Bundle app source
+COPY . /usr/src/app
+
+EXPOSE 3000
+CMD [ "npm", "start" ]

examples/cluster-httpd/server/index.js

@@ -0,0 +1,82 @@
+// 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';
+
+io.adapter(redis({ host: 'redis', port: 6379 }));
+
+server.listen(port, function () {
+  console.log('Server listening at port %d', port);
+  console.log('Hello, I\'m %s, how can I help?', serverName);
+});
+
+// Routing
+app.use(express.static(__dirname + '/public'));
+
+// Chatroom
+
+var numUsers = 0;
+
+io.on('connection', function (socket) {
+  socket.emit('my-name-is', serverName);
+
+  var addedUser = false;
+
+  // when the client emits 'new message', this listens and executes
+  socket.on('new message', function (data) {
+    // we tell the client to execute 'new message'
+    socket.broadcast.emit('new message', {
+      username: socket.username,
+      message: data
+    });
+  });
+
+  // when the client emits 'add user', this listens and executes
+  socket.on('add user', function (username) {
+    if (addedUser) return;
+
+    // we store the username in the socket session for this client
+    socket.username = username;
+    ++numUsers;
+    addedUser = true;
+    socket.emit('login', {
+      numUsers: numUsers
+    });
+    // echo globally (all clients) that a person has connected
+    socket.broadcast.emit('user joined', {
+      username: socket.username,
+      numUsers: numUsers
+    });
+  });
+
+  // when the client emits 'typing', we broadcast it to others
+  socket.on('typing', function () {
+    socket.broadcast.emit('typing', {
+      username: socket.username
+    });
+  });
+
+  // when the client emits 'stop typing', we broadcast it to others
+  socket.on('stop typing', function () {
+    socket.broadcast.emit('stop typing', {
+      username: socket.username
+    });
+  });
+
+  // when the user disconnects.. perform this
+  socket.on('disconnect', function () {
+    if (addedUser) {
+      --numUsers;
+
+      // echo globally that this client has left
+      socket.broadcast.emit('user left', {
+        username: socket.username,
+        numUsers: numUsers
+      });
+    }
+  });
+});

examples/cluster-httpd/server/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "socket.io-chat",
+  "version": "0.0.0",
+  "description": "A simple chat client using socket.io",
+  "main": "index.js",
+  "author": "Grant Timmerman",
+  "private": true,
+  "license": "BSD",
+  "dependencies": {
+    "express": "4.13.4",
+    "socket.io": "^3.1.0",
+    "socket.io-redis": "^6.0.1"
+  },
+  "scripts": {
+    "start": "node index.js"
+  }
+}

examples/cluster-httpd/server/public/index.html

@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Socket.IO Chat Example</title>
+  <link rel="stylesheet" href="style.css">
+</head>
+<body>
+  <ul class="pages">
+    <li class="chat page">
+      <div class="chatArea">
+        <ul class="messages"></ul>
+      </div>
+      <input class="inputMessage" placeholder="Type here..."/>
+    </li>
+    <li class="login page">
+      <div class="form">
+        <h3 class="title">What's your nickname?</h3>
+        <input class="usernameInput" type="text" maxlength="14" />
+      </div>
+    </li>
+  </ul>
+
+  <script src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
+  <script src="/socket.io/socket.io.js"></script>
+  <script src="/main.js"></script>
+</body>
+</html>

examples/cluster-httpd/server/public/main.js

@@ -0,0 +1,286 @@
+$(function() {
+  var FADE_TIME = 150; // ms
+  var TYPING_TIMER_LENGTH = 400; // ms
+  var COLORS = [
+    '#e21400', '#91580f', '#f8a700', '#f78b00',
+    '#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
+    '#3b88eb', '#3824aa', '#a700ff', '#d300e7'
+  ];
+
+  // Initialize variables
+  var $window = $(window);
+  var $usernameInput = $('.usernameInput'); // Input for username
+  var $messages = $('.messages'); // Messages area
+  var $inputMessage = $('.inputMessage'); // Input message input box
+
+  var $loginPage = $('.login.page'); // The login page
+  var $chatPage = $('.chat.page'); // The chatroom page
+
+  // Prompt for setting a username
+  var username;
+  var connected = false;
+  var typing = false;
+  var lastTypingTime;
+  var $currentInput = $usernameInput.focus();
+
+  var socket = io();
+
+  function addParticipantsMessage (data) {
+    var message = '';
+    if (data.numUsers === 1) {
+      message += "there's 1 participant";
+    } else {
+      message += "there are " + data.numUsers + " participants";
+    }
+    log(message);
+  }
+
+  // Sets the client's username
+  function setUsername () {
+    username = cleanInput($usernameInput.val().trim());
+
+    // If the username is valid
+    if (username) {
+      $loginPage.fadeOut();
+      $chatPage.show();
+      $loginPage.off('click');
+      $currentInput = $inputMessage.focus();
+
+      // Tell the server your username
+      socket.emit('add user', username);
+    }
+  }
+
+  // Sends a chat message
+  function sendMessage () {
+    var message = $inputMessage.val();
+    // Prevent markup from being injected into the message
+    message = cleanInput(message);
+    // if there is a non-empty message and a socket connection
+    if (message && connected) {
+      $inputMessage.val('');
+      addChatMessage({
+        username: username,
+        message: message
+      });
+      // tell server to execute 'new message' and send along one parameter
+      socket.emit('new message', message);
+    }
+  }
+
+  // Log a message
+  function log (message, options) {
+    var $el = $('<li>').addClass('log').text(message);
+    addMessageElement($el, options);
+  }
+
+  // Adds the visual chat message to the message list
+  function addChatMessage (data, options) {
+    // Don't fade the message in if there is an 'X was typing'
+    var $typingMessages = getTypingMessages(data);
+    options = options || {};
+    if ($typingMessages.length !== 0) {
+      options.fade = false;
+      $typingMessages.remove();
+    }
+
+    var $usernameDiv = $('<span class="username"/>')
+      .text(data.username)
+      .css('color', getUsernameColor(data.username));
+    var $messageBodyDiv = $('<span class="messageBody">')
+      .text(data.message);
+
+    var typingClass = data.typing ? 'typing' : '';
+    var $messageDiv = $('<li class="message"/>')
+      .data('username', data.username)
+      .addClass(typingClass)
+      .append($usernameDiv, $messageBodyDiv);
+
+    addMessageElement($messageDiv, options);
+  }
+
+  // Adds the visual chat typing message
+  function addChatTyping (data) {
+    data.typing = true;
+    data.message = 'is typing';
+    addChatMessage(data);
+  }
+
+  // Removes the visual chat typing message
+  function removeChatTyping (data) {
+    getTypingMessages(data).fadeOut(function () {
+      $(this).remove();
+    });
+  }
+
+  // Adds a message element to the messages and scrolls to the bottom
+  // el - The element to add as a message
+  // options.fade - If the element should fade-in (default = true)
+  // options.prepend - If the element should prepend
+  //   all other messages (default = false)
+  function addMessageElement (el, options) {
+    var $el = $(el);
+
+    // Setup default options
+    if (!options) {
+      options = {};
+    }
+    if (typeof options.fade === 'undefined') {
+      options.fade = true;
+    }
+    if (typeof options.prepend === 'undefined') {
+      options.prepend = false;
+    }
+
+    // Apply options
+    if (options.fade) {
+      $el.hide().fadeIn(FADE_TIME);
+    }
+    if (options.prepend) {
+      $messages.prepend($el);
+    } else {
+      $messages.append($el);
+    }
+    $messages[0].scrollTop = $messages[0].scrollHeight;
+  }
+
+  // Prevents input from having injected markup
+  function cleanInput (input) {
+    return $('<div/>').text(input).text();
+  }
+
+  // Updates the typing event
+  function updateTyping () {
+    if (connected) {
+      if (!typing) {
+        typing = true;
+        socket.emit('typing');
+      }
+      lastTypingTime = (new Date()).getTime();
+
+      setTimeout(function () {
+        var typingTimer = (new Date()).getTime();
+        var timeDiff = typingTimer - lastTypingTime;
+        if (timeDiff >= TYPING_TIMER_LENGTH && typing) {
+          socket.emit('stop typing');
+          typing = false;
+        }
+      }, TYPING_TIMER_LENGTH);
+    }
+  }
+
+  // Gets the 'X is typing' messages of a user
+  function getTypingMessages (data) {
+    return $('.typing.message').filter(function (i) {
+      return $(this).data('username') === data.username;
+    });
+  }
+
+  // Gets the color of a username through our hash function
+  function getUsernameColor (username) {
+    // Compute hash code
+    var hash = 7;
+    for (var i = 0; i < username.length; i++) {
+       hash = username.charCodeAt(i) + (hash << 5) - hash;
+    }
+    // Calculate color
+    var index = Math.abs(hash % COLORS.length);
+    return COLORS[index];
+  }
+
+  // Keyboard events
+
+  $window.keydown(function (event) {
+    // Auto-focus the current input when a key is typed
+    if (!(event.ctrlKey || event.metaKey || event.altKey)) {
+      $currentInput.focus();
+    }
+    // When the client hits ENTER on their keyboard
+    if (event.which === 13) {
+      if (username) {
+        sendMessage();
+        socket.emit('stop typing');
+        typing = false;
+      } else {
+        setUsername();
+      }
+    }
+  });
+
+  $inputMessage.on('input', function() {
+    updateTyping();
+  });
+
+  // Click events
+
+  // Focus input when clicking anywhere on login page
+  $loginPage.click(function () {
+    $currentInput.focus();
+  });
+
+  // Focus input when clicking on the message input's border
+  $inputMessage.click(function () {
+    $inputMessage.focus();
+  });
+
+  // Socket events
+
+  // Whenever the server emits 'login', log the login message
+  socket.on('login', function (data) {
+    connected = true;
+    // Display the welcome message
+    var message = "Welcome to Socket.IO Chat – ";
+    log(message, {
+      prepend: true
+    });
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'new message', update the chat body
+  socket.on('new message', function (data) {
+    addChatMessage(data);
+  });
+
+  // Whenever the server emits 'user joined', log it in the chat body
+  socket.on('user joined', function (data) {
+    log(data.username + ' joined');
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'user left', log it in the chat body
+  socket.on('user left', function (data) {
+    log(data.username + ' left');
+    addParticipantsMessage(data);
+    removeChatTyping(data);
+  });
+
+  // Whenever the server emits 'typing', show the typing message
+  socket.on('typing', function (data) {
+    addChatTyping(data);
+  });
+
+  // Whenever the server emits 'stop typing', kill the typing message
+  socket.on('stop typing', function (data) {
+    removeChatTyping(data);
+  });
+
+  socket.on('disconnect', function () {
+    log('you have been disconnected');
+  });
+
+  socket.on('reconnect', function () {
+    log('you have been reconnected');
+    if (username) {
+      socket.emit('add user', username);
+    }
+  });
+
+  socket.on('reconnect_error', function () {
+    log('attempt to reconnect has failed');
+  });
+
+  socket.on('my-name-is', function (serverName) {
+    log('host is now ' + serverName);
+  })
+
+});

examples/cluster-httpd/server/public/style.css

@@ -0,0 +1,149 @@
+/* Fix user-agent */
+
+* {
+  box-sizing: border-box;
+}
+
+html {
+  font-weight: 300;
+  -webkit-font-smoothing: antialiased;
+}
+
+html, input {
+  font-family:
+    "HelveticaNeue-Light",
+    "Helvetica Neue Light",
+    "Helvetica Neue",
+    Helvetica,
+    Arial,
+    "Lucida Grande",
+    sans-serif;
+}
+
+html, body {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+}
+
+ul {
+  list-style: none;
+  word-wrap: break-word;
+}
+
+/* Pages */
+
+.pages {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+  width: 100%;
+}
+
+.page {
+  height: 100%;
+  position: absolute;
+  width: 100%;
+}
+
+/* Login Page */
+
+.login.page {
+  background-color: #000;
+}
+
+.login.page .form {
+  height: 100px;
+  margin-top: -100px;
+  position: absolute;
+
+  text-align: center;
+  top: 50%;
+  width: 100%;
+}
+
+.login.page .form .usernameInput {
+  background-color: transparent;
+  border: none;
+  border-bottom: 2px solid #fff;
+  outline: none;
+  padding-bottom: 15px;
+  text-align: center;
+  width: 400px;
+}
+
+.login.page .title {
+  font-size: 200%;
+}
+
+.login.page .usernameInput {
+  font-size: 200%;
+  letter-spacing: 3px;
+}
+
+.login.page .title, .login.page .usernameInput {
+  color: #fff;
+  font-weight: 100;
+}
+
+/* Chat page */
+
+.chat.page {
+  display: none;
+}
+
+/* Font */
+
+.messages {
+  font-size: 150%;
+}
+
+.inputMessage {
+  font-size: 100%;
+}
+
+.log {
+  color: gray;
+  font-size: 70%;
+  margin: 5px;
+  text-align: center;
+}
+
+/* Messages */
+
+.chatArea {
+  height: 100%;
+  padding-bottom: 60px;
+}
+
+.messages {
+  height: 100%;
+  margin: 0;
+  overflow-y: scroll;
+  padding: 10px 20px 10px 20px;
+}
+
+.message.typing .messageBody {
+  color: gray;
+}
+
+.username {
+  font-weight: 700;
+  overflow: hidden;
+  padding-right: 15px;
+  text-align: right;
+}
+
+/* Input */
+
+.inputMessage {
+  border: 10px solid #000;
+  bottom: 0;
+  height: 60px;
+  left: 0;
+  outline: none;
+  padding-left: 10px;
+  position: absolute;
+  right: 0;
+  width: 100%;
+}

examples/cluster-nginx/README.md

@@ -0,0 +1,41 @@
+
+# Socket.IO Chat with nginx & redis
+
+A simple chat demo for socket.io
+
+## How to use
+
+Install [Docker Compose](https://docs.docker.com/compose/install/), then:
+
+```
+$ docker-compose up -d
+```
+
+And then point your browser to `http://localhost:3000`.
+
+This will start four Socket.IO nodes, behind a nginx proxy which will loadbalance the requests (using the IP of the client, see [ip_hash](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#ip_hash)).
+
+Each node connects to the redis backend, which will enable to broadcast to every client, no matter which node it is currently connected to.
+
+```
+# you can kill a given node, the client should reconnect to another node
+$ docker-compose stop server-george
+```
+
+A `client` container is included in the `docker-compose.yml` file, in order to test the routing.
+
+You can create additional `client` containers with:
+
+```
+$ docker-compose up -d --scale=client=10 client
+# and then
+$ docker-compose logs client
+```
+
+## Features
+
+- Multiple users can join a chat room by each entering a unique username
+on website load.
+- Users can type chat messages to the chat room.
+- A notification is sent to all users when a user joins or leaves
+the chatroom.

examples/cluster-nginx/client/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:14-alpine
+
+# Create app directory
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Install app dependencies
+COPY package.json /usr/src/app/
+RUN npm install --prod
+
+# Bundle app source
+COPY . /usr/src/app
+
+EXPOSE 3000
+CMD [ "npm", "start" ]

examples/cluster-nginx/client/index.js

@@ -0,0 +1,13 @@
+const socket = require('socket.io-client')('ws://nginx');
+
+socket.on('connect', () => {
+  console.log('connected');
+});
+
+socket.on('my-name-is', (serverName) => {
+  console.log(`connected to ${serverName}`);
+});
+
+socket.on('disconnect', (reason) => {
+  console.log(`disconnected due to ${reason}`);
+});

examples/cluster-nginx/client/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "socket.io-chat",
+  "version": "0.0.0",
+  "description": "A simple chat client using socket.io",
+  "main": "index.js",
+  "author": "Grant Timmerman",
+  "private": true,
+  "license": "MIT",
+  "dependencies": {
+    "socket.io-client": "^3.1.0"
+  },
+  "scripts": {
+    "start": "node index.js"
+  }
+}

examples/cluster-nginx/docker-compose.yml

@@ -0,0 +1,56 @@
+
+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-paul:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Paul
+
+server-george:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=George
+
+server-ringo:
+  build: ./server
+  links:
+    - redis
+  expose:
+    - "3000"
+  environment:
+    - NAME=Ringo
+
+client:
+  build: ./client
+  links:
+    - nginx
+
+redis:
+  image: redis:alpine
+  expose:
+    - "6379"

examples/cluster-nginx/nginx/Dockerfile

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

examples/cluster-nginx/nginx/nginx.conf

@@ -0,0 +1,39 @@
+# Reference: https://www.nginx.com/resources/wiki/start/topics/examples/full/
+
+worker_processes 4;
+
+events {
+  worker_connections 1024;
+}
+
+http {
+  server {
+    listen 80;
+
+    location / {
+      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+      proxy_set_header Host $host;
+
+      proxy_pass http://nodes;
+
+      # enable WebSockets
+      proxy_http_version 1.1;
+      proxy_set_header Upgrade $http_upgrade;
+      proxy_set_header Connection "upgrade";
+    }
+  }
+
+  upstream nodes {
+    # enable sticky session with either "hash" (uses the complete IP address)
+    hash $remote_addr consistent;
+    # or "ip_hash" (uses the first three octets of the client IPv4 address, or the entire IPv6 address)
+    # ip_hash;
+    # or "sticky" (needs commercial subscription)
+    # sticky cookie srv_id expires=1h domain=.example.com path=/;
+
+    server server-john:3000;
+    server server-paul:3000;
+    server server-george:3000;
+    server server-ringo:3000;
+  }
+}

examples/cluster-nginx/server/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:14-alpine
+
+# Create app directory
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Install app dependencies
+COPY package.json /usr/src/app/
+RUN npm install --prod
+
+# Bundle app source
+COPY . /usr/src/app
+
+EXPOSE 3000
+CMD [ "npm", "start" ]

examples/cluster-nginx/server/index.js

@@ -0,0 +1,82 @@
+// 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';
+
+io.adapter(redis({ host: 'redis', port: 6379 }));
+
+server.listen(port, function () {
+  console.log('Server listening at port %d', port);
+  console.log('Hello, I\'m %s, how can I help?', serverName);
+});
+
+// Routing
+app.use(express.static(__dirname + '/public'));
+
+// Chatroom
+
+var numUsers = 0;
+
+io.on('connection', function (socket) {
+  socket.emit('my-name-is', serverName);
+
+  var addedUser = false;
+
+  // when the client emits 'new message', this listens and executes
+  socket.on('new message', function (data) {
+    // we tell the client to execute 'new message'
+    socket.broadcast.emit('new message', {
+      username: socket.username,
+      message: data
+    });
+  });
+
+  // when the client emits 'add user', this listens and executes
+  socket.on('add user', function (username) {
+    if (addedUser) return;
+
+    // we store the username in the socket session for this client
+    socket.username = username;
+    ++numUsers;
+    addedUser = true;
+    socket.emit('login', {
+      numUsers: numUsers
+    });
+    // echo globally (all clients) that a person has connected
+    socket.broadcast.emit('user joined', {
+      username: socket.username,
+      numUsers: numUsers
+    });
+  });
+
+  // when the client emits 'typing', we broadcast it to others
+  socket.on('typing', function () {
+    socket.broadcast.emit('typing', {
+      username: socket.username
+    });
+  });
+
+  // when the client emits 'stop typing', we broadcast it to others
+  socket.on('stop typing', function () {
+    socket.broadcast.emit('stop typing', {
+      username: socket.username
+    });
+  });
+
+  // when the user disconnects.. perform this
+  socket.on('disconnect', function () {
+    if (addedUser) {
+      --numUsers;
+
+      // echo globally that this client has left
+      socket.broadcast.emit('user left', {
+        username: socket.username,
+        numUsers: numUsers
+      });
+    }
+  });
+});

examples/cluster-nginx/server/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "socket.io-chat",
+  "version": "0.0.0",
+  "description": "A simple chat client using socket.io",
+  "main": "index.js",
+  "author": "Grant Timmerman",
+  "private": true,
+  "license": "MIT",
+  "dependencies": {
+    "express": "4.13.4",
+    "socket.io": "^3.1.0",
+    "socket.io-redis": "^6.0.1"
+  },
+  "scripts": {
+    "start": "node index.js"
+  }
+}

examples/cluster-nginx/server/public/index.html

@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Socket.IO Chat Example</title>
+  <link rel="stylesheet" href="style.css">
+</head>
+<body>
+  <ul class="pages">
+    <li class="chat page">
+      <div class="chatArea">
+        <ul class="messages"></ul>
+      </div>
+      <input class="inputMessage" placeholder="Type here..."/>
+    </li>
+    <li class="login page">
+      <div class="form">
+        <h3 class="title">What's your nickname?</h3>
+        <input class="usernameInput" type="text" maxlength="14" />
+      </div>
+    </li>
+  </ul>
+
+  <script src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
+  <script src="/socket.io/socket.io.js"></script>
+  <script src="/main.js"></script>
+</body>
+</html>

examples/cluster-nginx/server/public/main.js

@@ -0,0 +1,286 @@
+$(function() {
+  var FADE_TIME = 150; // ms
+  var TYPING_TIMER_LENGTH = 400; // ms
+  var COLORS = [
+    '#e21400', '#91580f', '#f8a700', '#f78b00',
+    '#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
+    '#3b88eb', '#3824aa', '#a700ff', '#d300e7'
+  ];
+
+  // Initialize variables
+  var $window = $(window);
+  var $usernameInput = $('.usernameInput'); // Input for username
+  var $messages = $('.messages'); // Messages area
+  var $inputMessage = $('.inputMessage'); // Input message input box
+
+  var $loginPage = $('.login.page'); // The login page
+  var $chatPage = $('.chat.page'); // The chatroom page
+
+  // Prompt for setting a username
+  var username;
+  var connected = false;
+  var typing = false;
+  var lastTypingTime;
+  var $currentInput = $usernameInput.focus();
+
+  var socket = io();
+
+  function addParticipantsMessage (data) {
+    var message = '';
+    if (data.numUsers === 1) {
+      message += "there's 1 participant";
+    } else {
+      message += "there are " + data.numUsers + " participants";
+    }
+    log(message);
+  }
+
+  // Sets the client's username
+  function setUsername () {
+    username = cleanInput($usernameInput.val().trim());
+
+    // If the username is valid
+    if (username) {
+      $loginPage.fadeOut();
+      $chatPage.show();
+      $loginPage.off('click');
+      $currentInput = $inputMessage.focus();
+
+      // Tell the server your username
+      socket.emit('add user', username);
+    }
+  }
+
+  // Sends a chat message
+  function sendMessage () {
+    var message = $inputMessage.val();
+    // Prevent markup from being injected into the message
+    message = cleanInput(message);
+    // if there is a non-empty message and a socket connection
+    if (message && connected) {
+      $inputMessage.val('');
+      addChatMessage({
+        username: username,
+        message: message
+      });
+      // tell server to execute 'new message' and send along one parameter
+      socket.emit('new message', message);
+    }
+  }
+
+  // Log a message
+  function log (message, options) {
+    var $el = $('<li>').addClass('log').text(message);
+    addMessageElement($el, options);
+  }
+
+  // Adds the visual chat message to the message list
+  function addChatMessage (data, options) {
+    // Don't fade the message in if there is an 'X was typing'
+    var $typingMessages = getTypingMessages(data);
+    options = options || {};
+    if ($typingMessages.length !== 0) {
+      options.fade = false;
+      $typingMessages.remove();
+    }
+
+    var $usernameDiv = $('<span class="username"/>')
+      .text(data.username)
+      .css('color', getUsernameColor(data.username));
+    var $messageBodyDiv = $('<span class="messageBody">')
+      .text(data.message);
+
+    var typingClass = data.typing ? 'typing' : '';
+    var $messageDiv = $('<li class="message"/>')
+      .data('username', data.username)
+      .addClass(typingClass)
+      .append($usernameDiv, $messageBodyDiv);
+
+    addMessageElement($messageDiv, options);
+  }
+
+  // Adds the visual chat typing message
+  function addChatTyping (data) {
+    data.typing = true;
+    data.message = 'is typing';
+    addChatMessage(data);
+  }
+
+  // Removes the visual chat typing message
+  function removeChatTyping (data) {
+    getTypingMessages(data).fadeOut(function () {
+      $(this).remove();
+    });
+  }
+
+  // Adds a message element to the messages and scrolls to the bottom
+  // el - The element to add as a message
+  // options.fade - If the element should fade-in (default = true)
+  // options.prepend - If the element should prepend
+  //   all other messages (default = false)
+  function addMessageElement (el, options) {
+    var $el = $(el);
+
+    // Setup default options
+    if (!options) {
+      options = {};
+    }
+    if (typeof options.fade === 'undefined') {
+      options.fade = true;
+    }
+    if (typeof options.prepend === 'undefined') {
+      options.prepend = false;
+    }
+
+    // Apply options
+    if (options.fade) {
+      $el.hide().fadeIn(FADE_TIME);
+    }
+    if (options.prepend) {
+      $messages.prepend($el);
+    } else {
+      $messages.append($el);
+    }
+    $messages[0].scrollTop = $messages[0].scrollHeight;
+  }
+
+  // Prevents input from having injected markup
+  function cleanInput (input) {
+    return $('<div/>').text(input).text();
+  }
+
+  // Updates the typing event
+  function updateTyping () {
+    if (connected) {
+      if (!typing) {
+        typing = true;
+        socket.emit('typing');
+      }
+      lastTypingTime = (new Date()).getTime();
+
+      setTimeout(function () {
+        var typingTimer = (new Date()).getTime();
+        var timeDiff = typingTimer - lastTypingTime;
+        if (timeDiff >= TYPING_TIMER_LENGTH && typing) {
+          socket.emit('stop typing');
+          typing = false;
+        }
+      }, TYPING_TIMER_LENGTH);
+    }
+  }
+
+  // Gets the 'X is typing' messages of a user
+  function getTypingMessages (data) {
+    return $('.typing.message').filter(function (i) {
+      return $(this).data('username') === data.username;
+    });
+  }
+
+  // Gets the color of a username through our hash function
+  function getUsernameColor (username) {
+    // Compute hash code
+    var hash = 7;
+    for (var i = 0; i < username.length; i++) {
+       hash = username.charCodeAt(i) + (hash << 5) - hash;
+    }
+    // Calculate color
+    var index = Math.abs(hash % COLORS.length);
+    return COLORS[index];
+  }
+
+  // Keyboard events
+
+  $window.keydown(function (event) {
+    // Auto-focus the current input when a key is typed
+    if (!(event.ctrlKey || event.metaKey || event.altKey)) {
+      $currentInput.focus();
+    }
+    // When the client hits ENTER on their keyboard
+    if (event.which === 13) {
+      if (username) {
+        sendMessage();
+        socket.emit('stop typing');
+        typing = false;
+      } else {
+        setUsername();
+      }
+    }
+  });
+
+  $inputMessage.on('input', function() {
+    updateTyping();
+  });
+
+  // Click events
+
+  // Focus input when clicking anywhere on login page
+  $loginPage.click(function () {
+    $currentInput.focus();
+  });
+
+  // Focus input when clicking on the message input's border
+  $inputMessage.click(function () {
+    $inputMessage.focus();
+  });
+
+  // Socket events
+
+  // Whenever the server emits 'login', log the login message
+  socket.on('login', function (data) {
+    connected = true;
+    // Display the welcome message
+    var message = "Welcome to Socket.IO Chat – ";
+    log(message, {
+      prepend: true
+    });
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'new message', update the chat body
+  socket.on('new message', function (data) {
+    addChatMessage(data);
+  });
+
+  // Whenever the server emits 'user joined', log it in the chat body
+  socket.on('user joined', function (data) {
+    log(data.username + ' joined');
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'user left', log it in the chat body
+  socket.on('user left', function (data) {
+    log(data.username + ' left');
+    addParticipantsMessage(data);
+    removeChatTyping(data);
+  });
+
+  // Whenever the server emits 'typing', show the typing message
+  socket.on('typing', function (data) {
+    addChatTyping(data);
+  });
+
+  // Whenever the server emits 'stop typing', kill the typing message
+  socket.on('stop typing', function (data) {
+    removeChatTyping(data);
+  });
+
+  socket.on('disconnect', function () {
+    log('you have been disconnected');
+  });
+
+  socket.on('reconnect', function () {
+    log('you have been reconnected');
+    if (username) {
+      socket.emit('add user', username);
+    }
+  });
+
+  socket.on('reconnect_error', function () {
+    log('attempt to reconnect has failed');
+  });
+
+  socket.on('my-name-is', function (serverName) {
+    log('host is now ' + serverName);
+  })
+
+});

examples/cluster-nginx/server/public/style.css

@@ -0,0 +1,149 @@
+/* Fix user-agent */
+
+* {
+  box-sizing: border-box;
+}
+
+html {
+  font-weight: 300;
+  -webkit-font-smoothing: antialiased;
+}
+
+html, input {
+  font-family:
+    "HelveticaNeue-Light",
+    "Helvetica Neue Light",
+    "Helvetica Neue",
+    Helvetica,
+    Arial,
+    "Lucida Grande",
+    sans-serif;
+}
+
+html, body {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+}
+
+ul {
+  list-style: none;
+  word-wrap: break-word;
+}
+
+/* Pages */
+
+.pages {
+  height: 100%;
+  margin: 0;
+  padding: 0;
+  width: 100%;
+}
+
+.page {
+  height: 100%;
+  position: absolute;
+  width: 100%;
+}
+
+/* Login Page */
+
+.login.page {
+  background-color: #000;
+}
+
+.login.page .form {
+  height: 100px;
+  margin-top: -100px;
+  position: absolute;
+
+  text-align: center;
+  top: 50%;
+  width: 100%;
+}
+
+.login.page .form .usernameInput {
+  background-color: transparent;
+  border: none;
+  border-bottom: 2px solid #fff;
+  outline: none;
+  padding-bottom: 15px;
+  text-align: center;
+  width: 400px;
+}
+
+.login.page .title {
+  font-size: 200%;
+}
+
+.login.page .usernameInput {
+  font-size: 200%;
+  letter-spacing: 3px;
+}
+
+.login.page .title, .login.page .usernameInput {
+  color: #fff;
+  font-weight: 100;
+}
+
+/* Chat page */
+
+.chat.page {
+  display: none;
+}
+
+/* Font */
+
+.messages {
+  font-size: 150%;
+}
+
+.inputMessage {
+  font-size: 100%;
+}
+
+.log {
+  color: gray;
+  font-size: 70%;
+  margin: 5px;
+  text-align: center;
+}
+
+/* Messages */
+
+.chatArea {
+  height: 100%;
+  padding-bottom: 60px;
+}
+
+.messages {
+  height: 100%;
+  margin: 0;
+  overflow-y: scroll;
+  padding: 10px 20px 10px 20px;
+}
+
+.message.typing .messageBody {
+  color: gray;
+}
+
+.username {
+  font-weight: 700;
+  overflow: hidden;
+  padding-right: 15px;
+  text-align: right;
+}
+
+/* Input */
+
+.inputMessage {
+  border: 10px solid #000;
+  bottom: 0;
+  height: 60px;
+  left: 0;
+  outline: none;
+  padding-left: 10px;
+  position: absolute;
+  right: 0;
+  width: 100%;
+}

examples/cluster-traefik/README.md

@@ -0,0 +1,22 @@
+
+# Socket.IO Chat with traefik & [redis](https://redis.io/)
+
+A simple chat demo for Socket.IO
+
+## How to use
+
+Install [Docker Compose](https://docs.docker.com/compose/install/), then:
+
+```
+$ docker-compose up -d
+```
+
+And then point your browser to `http://localhost:3000`.
+
+You can then scale the server to multiple instances:
+
+```
+$ docker-compose up -d --scale=server=7
+```
+
+The session stickiness, which is [required](https://socket.io/docs/v3/using-multiple-nodes/) when using multiple Socket.IO server instances, is achieved with a cookie. More information [here](https://doc.traefik.io/traefik/v2.0/routing/services/#sticky-sessions).

examples/cluster-traefik/docker-compose.yml

@@ -0,0 +1,27 @@
+version: "3"
+
+services:
+  traefik:
+    image: traefik:2.4
+    volumes:
+      - ./traefik.yml:/etc/traefik/traefik.yml
+      - /var/run/docker.sock:/var/run/docker.sock
+    links:
+      - server
+    ports:
+     - "3000:80"
+     - "8080:8080"
+
+  server:
+    build: ./server
+    links:
+      - redis
+    labels:
+      - "traefik.http.routers.chat.rule=PathPrefix(`/`)"
+      - traefik.http.services.chat.loadBalancer.sticky.cookie.name=server_id
+      - traefik.http.services.chat.loadBalancer.sticky.cookie.httpOnly=true
+
+  redis:
+    image: redis:6-alpine
+    labels:
+      - traefik.enable=false

examples/cluster-traefik/server/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:14-alpine
+
+# Create app directory
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+# Install app dependencies
+COPY package.json /usr/src/app/
+RUN npm install --prod
+
+# Bundle app source
+COPY . /usr/src/app
+
+EXPOSE 3000
+CMD [ "npm", "start" ]

examples/cluster-traefik/server/index.js

@@ -0,0 +1,83 @@
+// 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 crypto = require('crypto');
+var serverName = crypto.randomBytes(3).toString('hex');
+
+io.adapter(redis({ host: 'redis', port: 6379 }));
+
+server.listen(port, function () {
+  console.log('Server listening at port %d', port);
+  console.log('Hello, I\'m %s, how can I help?', serverName);
+});
+
+// Routing
+app.use(express.static(__dirname + '/public'));
+
+// Chatroom
+
+var numUsers = 0;
+
+io.on('connection', function (socket) {
+  socket.emit('my-name-is', serverName);
+
+  var addedUser = false;
+
+  // when the client emits 'new message', this listens and executes
+  socket.on('new message', function (data) {
+    // we tell the client to execute 'new message'
+    socket.broadcast.emit('new message', {
+      username: socket.username,
+      message: data
+    });
+  });
+
+  // when the client emits 'add user', this listens and executes
+  socket.on('add user', function (username) {
+    if (addedUser) return;
+
+    // we store the username in the socket session for this client
+    socket.username = username;
+    ++numUsers;
+    addedUser = true;
+    socket.emit('login', {
+      numUsers: numUsers
+    });
+    // echo globally (all clients) that a person has connected
+    socket.broadcast.emit('user joined', {
+      username: socket.username,
+      numUsers: numUsers
+    });
+  });
+
+  // when the client emits 'typing', we broadcast it to others
+  socket.on('typing', function () {
+    socket.broadcast.emit('typing', {
+      username: socket.username
+    });
+  });
+
+  // when the client emits 'stop typing', we broadcast it to others
+  socket.on('stop typing', function () {
+    socket.broadcast.emit('stop typing', {
+      username: socket.username
+    });
+  });
+
+  // when the user disconnects.. perform this
+  socket.on('disconnect', function () {
+    if (addedUser) {
+      --numUsers;
+
+      // echo globally that this client has left
+      socket.broadcast.emit('user left', {
+        username: socket.username,
+        numUsers: numUsers
+      });
+    }
+  });
+});

examples/cluster-traefik/server/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "socket.io-chat",
+  "version": "0.0.0",
+  "description": "A simple chat client using socket.io",
+  "main": "index.js",
+  "author": "Grant Timmerman",
+  "private": true,
+  "license": "MIT",
+  "dependencies": {
+    "express": "4.13.4",
+    "socket.io": "^3.1.0",
+    "socket.io-redis": "^6.0.1"
+  },
+  "scripts": {
+    "start": "node index.js"
+  }
+}

examples/cluster-traefik/server/public/index.html

@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Socket.IO Chat Example</title>
+  <link rel="stylesheet" href="style.css">
+</head>
+<body>
+  <ul class="pages">
+    <li class="chat page">
+      <div class="chatArea">
+        <ul class="messages"></ul>
+      </div>
+      <input class="inputMessage" placeholder="Type here..."/>
+    </li>
+    <li class="login page">
+      <div class="form">
+        <h3 class="title">What's your nickname?</h3>
+        <input class="usernameInput" type="text" maxlength="14" />
+      </div>
+    </li>
+  </ul>
+
+  <script src="https://code.jquery.com/jquery-1.10.2.min.js"></script>
+  <script src="/socket.io/socket.io.js"></script>
+  <script src="/main.js"></script>
+</body>
+</html>

examples/cluster-traefik/server/public/main.js

@@ -0,0 +1,286 @@
+$(function() {
+  var FADE_TIME = 150; // ms
+  var TYPING_TIMER_LENGTH = 400; // ms
+  var COLORS = [
+    '#e21400', '#91580f', '#f8a700', '#f78b00',
+    '#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
+    '#3b88eb', '#3824aa', '#a700ff', '#d300e7'
+  ];
+
+  // Initialize variables
+  var $window = $(window);
+  var $usernameInput = $('.usernameInput'); // Input for username
+  var $messages = $('.messages'); // Messages area
+  var $inputMessage = $('.inputMessage'); // Input message input box
+
+  var $loginPage = $('.login.page'); // The login page
+  var $chatPage = $('.chat.page'); // The chatroom page
+
+  // Prompt for setting a username
+  var username;
+  var connected = false;
+  var typing = false;
+  var lastTypingTime;
+  var $currentInput = $usernameInput.focus();
+
+  var socket = io();
+
+  function addParticipantsMessage (data) {
+    var message = '';
+    if (data.numUsers === 1) {
+      message += "there's 1 participant";
+    } else {
+      message += "there are " + data.numUsers + " participants";
+    }
+    log(message);
+  }
+
+  // Sets the client's username
+  function setUsername () {
+    username = cleanInput($usernameInput.val().trim());
+
+    // If the username is valid
+    if (username) {
+      $loginPage.fadeOut();
+      $chatPage.show();
+      $loginPage.off('click');
+      $currentInput = $inputMessage.focus();
+
+      // Tell the server your username
+      socket.emit('add user', username);
+    }
+  }
+
+  // Sends a chat message
+  function sendMessage () {
+    var message = $inputMessage.val();
+    // Prevent markup from being injected into the message
+    message = cleanInput(message);
+    // if there is a non-empty message and a socket connection
+    if (message && connected) {
+      $inputMessage.val('');
+      addChatMessage({
+        username: username,
+        message: message
+      });
+      // tell server to execute 'new message' and send along one parameter
+      socket.emit('new message', message);
+    }
+  }
+
+  // Log a message
+  function log (message, options) {
+    var $el = $('<li>').addClass('log').text(message);
+    addMessageElement($el, options);
+  }
+
+  // Adds the visual chat message to the message list
+  function addChatMessage (data, options) {
+    // Don't fade the message in if there is an 'X was typing'
+    var $typingMessages = getTypingMessages(data);
+    options = options || {};
+    if ($typingMessages.length !== 0) {
+      options.fade = false;
+      $typingMessages.remove();
+    }
+
+    var $usernameDiv = $('<span class="username"/>')
+      .text(data.username)
+      .css('color', getUsernameColor(data.username));
+    var $messageBodyDiv = $('<span class="messageBody">')
+      .text(data.message);
+
+    var typingClass = data.typing ? 'typing' : '';
+    var $messageDiv = $('<li class="message"/>')
+      .data('username', data.username)
+      .addClass(typingClass)
+      .append($usernameDiv, $messageBodyDiv);
+
+    addMessageElement($messageDiv, options);
+  }
+
+  // Adds the visual chat typing message
+  function addChatTyping (data) {
+    data.typing = true;
+    data.message = 'is typing';
+    addChatMessage(data);
+  }
+
+  // Removes the visual chat typing message
+  function removeChatTyping (data) {
+    getTypingMessages(data).fadeOut(function () {
+      $(this).remove();
+    });
+  }
+
+  // Adds a message element to the messages and scrolls to the bottom
+  // el - The element to add as a message
+  // options.fade - If the element should fade-in (default = true)
+  // options.prepend - If the element should prepend
+  //   all other messages (default = false)
+  function addMessageElement (el, options) {
+    var $el = $(el);
+
+    // Setup default options
+    if (!options) {
+      options = {};
+    }
+    if (typeof options.fade === 'undefined') {
+      options.fade = true;
+    }
+    if (typeof options.prepend === 'undefined') {
+      options.prepend = false;
+    }
+
+    // Apply options
+    if (options.fade) {
+      $el.hide().fadeIn(FADE_TIME);
+    }
+    if (options.prepend) {
+      $messages.prepend($el);
+    } else {
+      $messages.append($el);
+    }
+    $messages[0].scrollTop = $messages[0].scrollHeight;
+  }
+
+  // Prevents input from having injected markup
+  function cleanInput (input) {
+    return $('<div/>').text(input).text();
+  }
+
+  // Updates the typing event
+  function updateTyping () {
+    if (connected) {
+      if (!typing) {
+        typing = true;
+        socket.emit('typing');
+      }
+      lastTypingTime = (new Date()).getTime();
+
+      setTimeout(function () {
+        var typingTimer = (new Date()).getTime();
+        var timeDiff = typingTimer - lastTypingTime;
+        if (timeDiff >= TYPING_TIMER_LENGTH && typing) {
+          socket.emit('stop typing');
+          typing = false;
+        }
+      }, TYPING_TIMER_LENGTH);
+    }
+  }
+
+  // Gets the 'X is typing' messages of a user
+  function getTypingMessages (data) {
+    return $('.typing.message').filter(function (i) {
+      return $(this).data('username') === data.username;
+    });
+  }
+
+  // Gets the color of a username through our hash function
+  function getUsernameColor (username) {
+    // Compute hash code
+    var hash = 7;
+    for (var i = 0; i < username.length; i++) {
+       hash = username.charCodeAt(i) + (hash << 5) - hash;
+    }
+    // Calculate color
+    var index = Math.abs(hash % COLORS.length);
+    return COLORS[index];
+  }
+
+  // Keyboard events
+
+  $window.keydown(function (event) {
+    // Auto-focus the current input when a key is typed
+    if (!(event.ctrlKey || event.metaKey || event.altKey)) {
+      $currentInput.focus();
+    }
+    // When the client hits ENTER on their keyboard
+    if (event.which === 13) {
+      if (username) {
+        sendMessage();
+        socket.emit('stop typing');
+        typing = false;
+      } else {
+        setUsername();
+      }
+    }
+  });
+
+  $inputMessage.on('input', function() {
+    updateTyping();
+  });
+
+  // Click events
+
+  // Focus input when clicking anywhere on login page
+  $loginPage.click(function () {
+    $currentInput.focus();
+  });
+
+  // Focus input when clicking on the message input's border
+  $inputMessage.click(function () {
+    $inputMessage.focus();
+  });
+
+  // Socket events
+
+  // Whenever the server emits 'login', log the login message
+  socket.on('login', function (data) {
+    connected = true;
+    // Display the welcome message
+    var message = "Welcome to Socket.IO Chat – ";
+    log(message, {
+      prepend: true
+    });
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'new message', update the chat body
+  socket.on('new message', function (data) {
+    addChatMessage(data);
+  });
+
+  // Whenever the server emits 'user joined', log it in the chat body
+  socket.on('user joined', function (data) {
+    log(data.username + ' joined');
+    addParticipantsMessage(data);
+  });
+
+  // Whenever the server emits 'user left', log it in the chat body
+  socket.on('user left', function (data) {
+    log(data.username + ' left');
+    addParticipantsMessage(data);
+    removeChatTyping(data);
+  });
+
+  // Whenever the server emits 'typing', show the typing message
+  socket.on('typing', function (data) {
+    addChatTyping(data);
+  });
+
+  // Whenever the server emits 'stop typing', kill the typing message
+  socket.on('stop typing', function (data) {
+    removeChatTyping(data);
+  });
+
+  socket.on('disconnect', function () {
+    log('you have been disconnected');
+  });
+
+  socket.on('connect', function () {
+    if (username) {
+      log('you have been reconnected');
+      socket.emit('add user', username);
+    }
+  });
+
+  socket.io.on('reconnect_error', function () {
+    log('attempt to reconnect has failed');
+  });
+
+  socket.on('my-name-is', function (serverName) {
+    log('host is now ' + serverName);
+  })
+
+});