chore(release): 4.5.0

Diff: https://github.com/socketio/socket.io/compare/4.4.1...4.5.0

.github/ISSUE_TEMPLATE.md

@@ -1,32 +0,0 @@
-
-**Note**: for support questions, please use one of these channels: [stackoverflow](http://stackoverflow.com/questions/tagged/socket.io) or [slack](https://socketio.slack.com)
-
-For bug reports and feature requests for the **Swift client**, please open an issue [there](https://github.com/socketio/socket.io-client-swift).
-
-For bug reports and feature requests for the **Java client**, please open an issue [there](https://github.com/socketio/socket.io-client-java).
-
-### You want to:
-
-* [x] report a *bug*
-* [ ] request a *feature*
-
-### Current behaviour
-
-*What is actually happening?*
-
-### Steps to reproduce (if the current behaviour is a bug)
-
-**Note**: the best way (and by that we mean **the only way**) to get a quick answer is to provide a failing test case by forking the following [fiddle](https://github.com/socketio/socket.io-fiddle).
-
-### Expected behaviour
-
-*What is expected?*
-
-### Setup
-- OS:
-- browser:
-- socket.io version:
-
-### Other information (e.g. stacktraces, related issues, suggestions how to fix)
-
-

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,61 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: 'to triage'
+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

@@ -7,10 +7,10 @@
 * [ ] a code change that improves performance
 * [ ] other
 
-### Current behaviour
+### Current behavior
 
 
-### New behaviour
+### 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: [12, 14, 16]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm test
+        env:
+          CI: true

.replit

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

.travis.yml

@@ -1,10 +0,0 @@
-language: node_js
-sudo: false
-node_js:
-  - '10'
-  - '12'
-  - '14'
-notifications:
-  irc: "irc.freenode.org#socket.io"
-git:
-  depth: 1

CHANGELOG.md

@@ -1,3 +1,248 @@
+# [4.5.0](https://github.com/socketio/socket.io/compare/4.4.1...4.5.0) (2022-04-23)
+
+
+### Bug Fixes
+
+* **typings:** ensure compatibility with TypeScript 3.x ([#4259](https://github.com/socketio/socket.io/issues/4259)) ([02c87a8](https://github.com/socketio/socket.io/commit/02c87a85614e217b8e7b93753f315790ae9d99f6))
+
+
+### Features
+
+* add support for catch-all listeners for outgoing packets ([531104d](https://github.com/socketio/socket.io/commit/531104d332690138b7aab84d5583d6204132c8b4))
+
+This is similar to `onAny()`, but for outgoing packets.
+
+Syntax:
+
+```js
+socket.onAnyOutgoing((event, ...args) => {
+  console.log(event);
+});
+```
+
+* broadcast and expect multiple acks ([8b20457](https://github.com/socketio/socket.io/commit/8b204570a94979bbec307f23ca078f30f5cf07b0))
+
+Syntax:
+
+```js
+io.timeout(1000).emit("some-event", (err, responses) => {
+  // ...
+});
+```
+
+* add the "maxPayload" field in the handshake details ([088dcb4](https://github.com/socketio/engine.io/commit/088dcb4dff60df39785df13d0a33d3ceaa1dff38))
+
+So that clients in HTTP long-polling can decide how many packets they have to send to stay under the maxHttpBufferSize
+value.
+
+This is a backward compatible change which should not mandate a new major revision of the protocol (we stay in v4), as
+we only add a field in the JSON-encoded handshake data:
+
+```
+0{"sid":"lv_VI97HAXpY6yYWAAAC","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":5000,"maxPayload":1000000}
+```
+
+
+
+## [4.4.1](https://github.com/socketio/socket.io/compare/4.4.0...4.4.1) (2022-01-06)
+
+
+### Bug Fixes
+
+* **types:** make `RemoteSocket.data` type safe ([#4234](https://github.com/socketio/socket.io/issues/4234)) ([770ee59](https://github.com/socketio/socket.io/commit/770ee5949fb47c2556876c622f06c862573657d6))
+* **types:** pass `SocketData` type to custom namespaces ([#4233](https://github.com/socketio/socket.io/issues/4233)) ([f2b8de7](https://github.com/socketio/socket.io/commit/f2b8de71919e1b4d3e57f15a459972c1d1064787))
+
+
+
+# [4.4.0](https://github.com/socketio/socket.io/compare/4.3.2...4.4.0) (2021-11-18)
+
+
+### Bug Fixes
+
+* only set 'connected' to true after middleware execution ([02b0f73](https://github.com/socketio/socket.io/commit/02b0f73e2c64b09c72c5fbf7dc5f059557bdbe50))
+
+
+### Features
+
+* add an implementation based on uWebSockets.js ([c0d8c5a](https://github.com/socketio/socket.io/commit/c0d8c5ab234d0d2bef0d0dec472973cc9662f647))
+* add timeout feature ([f0ed42f](https://github.com/socketio/socket.io/commit/f0ed42f18cabef20ad976aeec37077b6bf3837a5))
+* add type information to `socket.data` ([#4159](https://github.com/socketio/socket.io/issues/4159)) ([fe8730c](https://github.com/socketio/socket.io/commit/fe8730ca0f15bc92d5de81cf934c89c76d6af329))
+
+
+
+## [4.3.2](https://github.com/socketio/socket.io/compare/4.3.1...4.3.2) (2021-11-08)
+
+
+### Bug Fixes
+
+* fix race condition in dynamic namespaces ([#4137](https://github.com/socketio/socket.io/issues/4137)) ([9d86397](https://github.com/socketio/socket.io/commit/9d86397243bcbb5775a29d96e5ef03e17148a8e7))
+
+
+## [4.3.1](https://github.com/socketio/socket.io/compare/4.3.0...4.3.1) (2021-10-16)
+
+
+### Bug Fixes
+
+* fix server attachment ([#4127](https://github.com/socketio/socket.io/issues/4127)) ([0ef2a4d](https://github.com/socketio/socket.io/commit/0ef2a4d02c9350aff163df9cb61aece89c4dac0f))
+
+
+# [4.3.0](https://github.com/socketio/socket.io/compare/4.2.0...4.3.0) (2021-10-14)
+
+
+### Bug Fixes
+
+* **typings:** add name field to cookie option ([#4099](https://github.com/socketio/socket.io/issues/4099)) ([033c5d3](https://github.com/socketio/socket.io/commit/033c5d399a2b985afad32c1e4b0c16d764e248cd))
+* send volatile packets with binary attachments ([dc81fcf](https://github.com/socketio/socket.io/commit/dc81fcf461cfdbb5b34b1a5a96b84373754047d5))
+
+
+### Features
+
+* serve ESM bundle ([60edecb](https://github.com/socketio/socket.io/commit/60edecb3bd33801803cdcba0aefbafa381a2abb3))
+
+
+# [4.2.0](https://github.com/socketio/socket.io/compare/4.1.3...4.2.0) (2021-08-30)
+
+
+### Bug Fixes
+
+* **typings:** allow async listener in typed events ([ccfd8ca](https://github.com/socketio/socket.io/commit/ccfd8caba6d38b7ba6c5114bd8179346ed07671c))
+
+
+### Features
+
+* ignore the query string when serving client JavaScript ([#4024](https://github.com/socketio/socket.io/issues/4024)) ([24fee27](https://github.com/socketio/socket.io/commit/24fee27ba36485308f8e995879c10931532c814e))
+
+
+## [4.1.3](https://github.com/socketio/socket.io/compare/4.1.2...4.1.3) (2021-07-10)
+
+
+### Bug Fixes
+
+* fix io.except() method ([94e27cd](https://github.com/socketio/socket.io/commit/94e27cd072c8a4eeb9636f6ffbb7a21d382f36b0))
+* remove x-sourcemap header ([a4dffc6](https://github.com/socketio/socket.io/commit/a4dffc6527f412d51a786ae5bf2e9080fe1ca63c))
+
+
+## [4.1.2](https://github.com/socketio/socket.io/compare/4.1.1...4.1.2) (2021-05-17)
+
+
+### Bug Fixes
+
+* **typings:** ensure compatibility with TypeScript 3.x ([0cb6ac9](https://github.com/socketio/socket.io/commit/0cb6ac95b49a27483b6f1b6402fa54b35f82e36f))
+* ensure compatibility with previous versions of the adapter ([a2cf248](https://github.com/socketio/socket.io/commit/a2cf2486c366cb62293101c10520c57f6984a3fc))
+
+
+## [4.1.1](https://github.com/socketio/socket.io/compare/4.1.0...4.1.1) (2021-05-11)
+
+
+### Bug Fixes
+
+* **typings:** properly type server-side events ([b84ed1e](https://github.com/socketio/socket.io/commit/b84ed1e41c9053792caf58974c5de9395bfd509f))
+* **typings:** properly type the adapter attribute ([891b187](https://github.com/socketio/socket.io/commit/891b1870e92d1ec38910f03bb839817e2d6be65a))
+
+
+# [4.1.0](https://github.com/socketio/socket.io/compare/4.0.2...4.1.0) (2021-05-11)
+
+
+### Features
+
+* add support for inter-server communication ([93cce05](https://github.com/socketio/socket.io/commit/93cce05fb3faf91f21fa71212275c776aa161107))
+* notify upon namespace creation ([499c892](https://github.com/socketio/socket.io/commit/499c89250d2db1ab7725ab2b74840e188c267c46))
+* add a "connection_error" event ([7096e98](https://github.com/socketio/engine.io/commit/7096e98a02295a62c8ea2aa56461d4875887092d), from `engine.io`)
+* add the "initial_headers" and "headers" events ([2527543](https://github.com/socketio/engine.io/commit/252754353a0e88eb036ebb3082e9d6a9a5f497db), from `engine.io`)
+
+
+### Performance Improvements
+
+* add support for the "wsPreEncoded" writing option ([dc381b7](https://github.com/socketio/socket.io/commit/dc381b72c6b2f8172001dedd84116122e4cc95b3))
+
+
+## [4.0.2](https://github.com/socketio/socket.io/compare/4.0.1...4.0.2) (2021-05-06)
+
+
+### Bug Fixes
+
+* **typings:** make "engine" attribute public ([b81ce4c](https://github.com/socketio/socket.io/commit/b81ce4c9d0b00666361498e2ba5e0d007d5860b8))
+* properly export the Socket class ([d65b6ee](https://github.com/socketio/socket.io/commit/d65b6ee84c8e91deb61c3c1385eb19afa196a909))
+
+
+## [4.0.1](https://github.com/socketio/socket.io/compare/4.0.0...4.0.1) (2021-03-31)
+
+
+### Bug Fixes
+
+* **typings:** add fallback to untyped event listener ([#3834](https://github.com/socketio/socket.io/issues/3834)) ([a11152f](https://github.com/socketio/socket.io/commit/a11152f42b281df83409313962f60f230239c79e))
+* **typings:** update return type from emit ([#3843](https://github.com/socketio/socket.io/issues/3843)) ([1a72ae4](https://github.com/socketio/socket.io/commit/1a72ae4fe27a14cf60916f991a2c94da91d9e54a))
+
+
+# [4.0.0](https://github.com/socketio/socket.io/compare/3.1.2...4.0.0) (2021-03-10)
+
+
+### Bug Fixes
+
+* make io.to(...) immutable ([ac9e8ca](https://github.com/socketio/socket.io/commit/ac9e8ca6c71e00d4af45ee03f590fe56f3951186))
+
+
+### Features
+
+* add some utility methods ([b25495c](https://github.com/socketio/socket.io/commit/b25495c069031674da08e19aed68922c7c7a0e28))
+* add support for typed events ([#3822](https://github.com/socketio/socket.io/issues/3822)) ([0107510](https://github.com/socketio/socket.io/commit/0107510ba8a0f148c78029d8be8919b350feb633))
+* allow to exclude specific rooms when broadcasting ([#3789](https://github.com/socketio/socket.io/issues/3789)) ([7de2e87](https://github.com/socketio/socket.io/commit/7de2e87e888d849eb2dfc5e362af4c9e86044701))
+* allow to pass an array to io.to(...) ([085d1de](https://github.com/socketio/socket.io/commit/085d1de9df909651de8b313cc6f9f253374b702e))
+
+
+## [3.1.2](https://github.com/socketio/socket.io/compare/3.1.1...3.1.2) (2021-02-26)
+
+
+### Bug Fixes
+
+* ignore packets received after disconnection ([494c64e](https://github.com/socketio/socket.io/commit/494c64e44f645cbd24c645f1186d203789e84af0))
+
+
+## [3.1.1](https://github.com/socketio/socket.io/compare/3.1.0...3.1.1) (2021-02-03)
+
+
+### 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)
 
 

Readme.md

@@ -1,10 +1,7 @@
-
 # socket.io
-
+[![Run on Repl.it](https://repl.it/badge/github/socketio/socket.io)](https://replit.com/@socketio/socketio-minimal-example)
 [![Backers on Open Collective](https://opencollective.com/socketio/backers/badge.svg)](#backers) [![Sponsors on Open Collective](https://opencollective.com/socketio/sponsors/badge.svg)](#sponsors)
-[![Build Status](https://secure.travis-ci.org/socketio/socket.io.svg?branch=master)](https://travis-ci.org/socketio/socket.io)
-[![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)
+[![Build Status](https://github.com/socketio/socket.io/workflows/CI/badge.svg)](https://github.com/socketio/socket.io/actions)
 [![NPM version](https://badge.fury.io/js/socket.io.svg)](https://www.npmjs.com/package/socket.io)
 ![Downloads](https://img.shields.io/npm/dm/socket.io.svg?style=flat)
 [![](https://slackin-socketio.now.sh/badge.svg)](https://slackin-socketio.now.sh)
@@ -22,6 +19,8 @@ Some implementations in other languages are also available:
 - [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/doghappy/socket.io-client-csharp)
 
 Its main features are:
 
@@ -35,7 +34,7 @@ For this purpose, it relies on [Engine.IO](https://github.com/socketio/engine.io
 
 #### 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://github.com/socketio/socket.io-client/blob/master/docs/API.md#new-managerurl-options).
+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
 
@@ -84,7 +83,11 @@ This is a useful feature to send notifications to a group of users, or to a give
 ## Installation
 
 ```bash
+// with npm
 npm install socket.io
+
+// with yarn
+yarn add socket.io
 ```
 
 ## How to use
@@ -110,6 +113,14 @@ io.on('connection', client => { ... });
 io.listen(3000);
 ```
 
+### Module syntax 
+
+```js
+import { Server } from "socket.io";
+const io = new Server(server);
+io.listen(3000);
+```
+
 ### In conjunction with Express
 
 Starting with **3.0**, express applications have become request handler

examples/.gitignore

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

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": "^4.0.0",
+    "socket.io-client": "^4.0.0",
+    "tslib": "^2.0.0",
+    "zone.js": "~0.10.2"
+  },
+  "devDependencies": {
+    "@angular-devkit/build-angular": "~0.1100.4",
+    "@angular/cli": "~11.0.4",
+    "@angular/compiler-cli": "~11.0.4",
+    "@types/jasmine": "~3.6.0",
+    "@types/node": "^12.11.1",
+    "codelyzer": "^6.0.0",
+    "jasmine-core": "~3.6.0",
+    "jasmine-spec-reporter": "~5.0.0",
+    "karma": "~5.1.0",
+    "karma-chrome-launcher": "~3.1.0",
+    "karma-coverage": "~2.0.3",
+    "karma-jasmine": "~4.0.0",
+    "karma-jasmine-html-reporter": "^1.5.0",
+    "protractor": "~7.0.0",
+    "ts-node": "~8.3.0",
+    "tslint": "~6.1.0",
+    "typescript": "~4.0.2"
+  }
+}

examples/angular-todomvc/server.ts

@@ -0,0 +1,28 @@
+import { Server } 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.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/basic-crud-application/README.md

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

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

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

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

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

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

@@ -0,0 +1,46 @@
+# See http://help.github.com/ignore-files/ for more about ignoring files.
+
+# compiled output
+/dist
+/tmp
+/out-tsc
+# Only exists if Bazel was run
+/bazel-out
+
+# dependencies
+/node_modules
+
+# profiling files
+chrome-profiler-events*.json
+speed-measure-plugin*.json
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+.history/*
+
+# misc
+/.sass-cache
+/connect.lock
+/coverage
+/libpeerconnection.log
+npm-debug.log
+yarn-error.log
+testem.log
+/typings
+
+# System Files
+.DS_Store
+Thumbs.db

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

@@ -0,0 +1,37 @@
+{
+  "name": "basic-crud-server",
+  "version": "0.0.1",
+  "description": "Server for the Basic CRUD Socket.IO example",
+  "main": "dist/lib/index.js",
+  "scripts": {
+    "start": "ts-node lib/index.ts",
+    "build": "tsc",
+    "test": "nyc mocha --require ts-node/register test/**/*.ts"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/socketio/socket.io.git"
+  },
+  "author": "Damien Arrachequesne <damien.arrachequesne@gmail.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/socketio/socket.io/issues"
+  },
+  "homepage": "https://github.com/socketio/socket.io#readme",
+  "dependencies": {
+    "joi": "^17.4.0",
+    "socket.io": "^4.0.1",
+    "uuid": "^8.3.2"
+  },
+  "devDependencies": {
+    "@types/mocha": "^8.2.3",
+    "@types/chai": "^4.2.16",
+    "@types/uuid": "^8.3.0",
+    "chai": "^4.3.4",
+    "mocha": "^8.3.2",
+    "nyc": "^15.1.0",
+    "socket.io-client": "^4.0.1",
+    "ts-node": "^9.1.1",
+    "typescript": "^4.2.4"
+  }
+}

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

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