Chat Application Backend Documentation

This is a simple yet powerful backend server for a chat application, built using Fastify and Socket.IO. It handles user authentication, channel management, and real-time communication with ease.

🔗 Frontend Example Repository: Chat App Frontend

🚀 Installation

To install the necessary package, use the following command:

npm i -s chat-app-server

🏃 Running the Server

To start the server, run:

npx start-server

🔧 Options for start-server

Usage: start-server [OPTIONS]

Options:
  -a, --address <address>  Specify the address to listen on (default: "0.0.0.0")
  -p, --port <port>        Specify the port to listen on (default: 5001)
  -s, --static <path>      Path to static asset files (default: "./build")
  -r, --rule <rule>        Set server rules as a comma-separated list:
                           - First value: Allow all users to delete/rename channels (true/false)
                           - Second value: Allow all users to edit messages (true/false)
                           (default: "true,true")
  -h, --help               Display help for the command

⚙️ Rule Settings (-r or --rule)

The -r or --rule option accepts a pair of boolean values to configure server behavior.

1. Channel Editing Rule

   • true: All users can delete or rename channels.
   • false: Only admins can delete or rename channels.

2. Message Editing Rule

   • true: All users can edit their own messages.
   • false: Only admins can edit messages.

Example:

npx start-server -a 127.0.0.1 -p 8080 -r false,true

🔑 User Management API

1. Create New User

Endpoint: POST /api/account/signup

Example Request:

axios.post('/api/account/signup', { username: 'user', password: '123456' })
  .then((response) => {
    console.log(response.data); // => { token: ... }
  });

2. Login

Endpoint: POST /api/account/login

Example Request:

axios.post('/api/account/login', { username: 'user', password: '123456' })
  .then((response) => {
    console.log(response.data); // => { token: ... }
  });

3. Delete

Endpoint: DELETE /api/account/:username

Example Request:

// Admins can delete any user account. Regular users can only delete their own.
axios.delete('/api/account/user', {
    headers: {
      Authorization: `Bearer ${token}`,
    },
  }
).then((response) => {
  console.log(response.data); // Example response: { username: 'user' }
});

4. Rename

Endpoint: PATCH /api/account/:username

Example Request:

// Admins can renames any user account. Regular users can only rename their own.
axios.patch('/api/account/user', { username: 'newName' }, {
    headers: {
      Authorization: `Bearer ${token}`,
    },
  }
).then((response) => {
  console.log(response.data); // Example response: { username: 'newName' }
});

📺 Channel Management API

1. Get Channels

Endpoint: GET /api/channels

Example Request:

axios.get('/api/channels', {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => [{ id: '1', name: 'general', removable: false }, ...]
});

2. Add Channel

Endpoint: POST /api/channels

Example Request:

const newChannel = { name: 'new channel' };

axios.post('/api/channels', newChannel, {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '3', name: 'new channel', removable: true }
});

3. Edit Channel

Endpoint: PATCH /api/channels/:id

Example Request:

const editedChannel = { name: 'new name channel' };

axios.patch('/api/channels/3', editedChannel, {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '3', name: 'new name channel', removable: true }
});

4. Remove Channel

Endpoint: DELETE /api/channels/:id

Example Request:

axios.delete('/api/channels/3', {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '3' }
});

💬 Message Management API

1. Get Messages

Endpoint: GET /api/messages

Example Request:

axios.get('/api/messages', {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => [{ id: '1', body: 'text message', channelId: '1', username: 'user' }, ...]
});

2. Add Message

Endpoint: POST /api/messages

Example Request:

const newMessage = { body: 'new message', channelId: '1' };

axios.post('/api/messages', newMessage, {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '1', body: 'new message', channelId: '1', username: 'user' }
});

3. Edit Message

Endpoint: PATCH /api/messages/:id

Example Request:

const editedMessage = { body: 'new body message' };

axios.patch('/api/messages/1', editedMessage, {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '1', body: 'edited message', channelId: '1', username: 'user' }
});

4. Remove Message

Endpoint: DELETE /api/messages/:id

Example Request:

axios.delete('/api/messages/3', {
  headers: {
    Authorization: `Bearer ${token}`,
  },
}).then((response) => {
  console.log(response.data); // => { id: '3' }
});

📡 Socket.IO Event Subscriptions

Set up Socket.io

const socket = io({
  extraHeaders: {
    authorization: `Bearer ${token}`,
  },
});

1. Subscribe new messages

socket.on('newMessage', (payload) => {
  console.log(payload); // => { id: '2', body: 'edited message', channelId: '1', username: 'user' }
});

2. Subscribe new channel

socket.on('newChannel', (payload) => {
  console.log(payload) // { id: '6', name: "new channel", removable: true }
});
  

3. Subscribe remove channel

socket.on('removeChannel', (payload) => {
  console.log(payload); // { id: '6' };
});

4. Subscribe rename channel

socket.on('renameChannel', (payload) => {
  console.log(payload); // { id: '7', name: "new name channel", removable: true }
});

🛠️ Tech Stack

Backend

• Fastify: A fast and low-overhead web framework for Node.js, perfect for building high-performance APIs.
• fastify-socket.io: A Fastify plugin that integrates with Socket.IO for real-time communication via WebSockets.
• lodash: A utility library providing helpful methods for working with arrays, objects, and functions, making code more concise and easier to manage.
• commander: A package for building command-line interfaces (CLI) with ease, enabling interaction with Node.js applications through the terminal.
• http-errors: A simple utility for creating HTTP error objects to standardize error handling in APIs.
• socket.io: A library that enables real-time, bi-directional communication between clients and servers via WebSockets.

Development Tools

• ESLint: A tool for identifying and fixing problems in JavaScript code, helping to maintain code quality and consistency.

📝 License

This project is licensed under the MIT License, giving you the freedom to use, modify, and distribute the application as needed.

Developed with ❤️ by Stephan