Backend Learning - Todo Application

A full-stack todo application built with Node.js, Express.js, SQLite, and JWT authentication. This project demonstrates modern backend development practices with TypeScript.

🚀 Features

• User Authentication: Secure registration and login with JWT tokens
• Password Security: Passwords are hashed using bcrypt
• Todo Management: Create, read, update, and delete todos
• User-specific Data: Each user can only access their own todos
• SQLite Database: Lightweight database with foreign key constraints
• TypeScript: Full type safety throughout the application
• Responsive UI: Clean and modern frontend interface

🛠️ Tech Stack

Backend

• Node.js - Runtime environment
• Express.js - Web application framework
• TypeScript - Type-safe JavaScript
• SQLite - Lightweight database
• better-sqlite3 - SQLite driver for Node.js
• JWT - JSON Web Tokens for authentication
• bcryptjs - Password hashing

Frontend

• HTML5 - Markup language
• CSS3 - Styling
• Vanilla JavaScript - Client-side logic
• Font Awesome - Icons

Development Tools

• tsx - TypeScript execution engine
• ESLint - Code linting
• Prettier - Code formatting
• pnpm - Package manager

📁 Project Structure

backend-learning/
├── src/
│   ├── db.ts                    # Database configuration and schema
│   ├── server.ts                # Main server file
│   ├── middleware/
│   │   └── auth-middleware.ts   # JWT authentication middleware
│   └── routes/
│       ├── auth-routes.ts       # Authentication routes
│       └── todo-routes.ts       # Todo CRUD routes
├── public/
│   ├── index.html              # Frontend HTML
│   ├── styles.css              # Custom styles
│   └── fanta.css               # Additional styling
├── .env.example                # Environment variables template
├── package.json                # Project dependencies
├── tsconfig.json               # TypeScript configuration
└── README.md                   # This file

🚦 Getting Started

Prerequisites

• Node.js (v18 or higher)
• pnpm (or npm/yarn)

Installation

1. Clone the repository

   git clone https://github.com/JimmFly/backend-learning.git
   cd backend-learning

2. Install dependencies

   pnpm install

3. Set up environment variables

   cp .env.example .env

   Edit .env and add your JWT secret:

   JWT_SECRET=your-super-secret-jwt-key-here
   PORT=3000
   

4. Start the development server

   pnpm dev

5. Access the application Open your browser and navigate to http://localhost:3000

📝 API Endpoints

Authentication Routes (/auth)

Method	Endpoint	Description	Body
GET	/auth	Get all users (development only)	-
POST	/auth/register	Register a new user	{username, password}
POST	/auth/login	Login user	{username, password}
DELETE	/auth/delete-account	Delete user account	{username, password}

Todo Routes (/todos) - Protected

Method	Endpoint	Description	Body	Headers
GET	/todos	Get all user's todos	-	Authorization: <token>
POST	/todos	Create a new todo	{task}	Authorization: <token>
PUT	/todos/:id	Update a todo	{task?, completed?}	Authorization: <token>
DELETE	/todos/:id	Delete a todo	-	Authorization: <token>

🗄️ Database Schema

Users Table

CREATE TABLE users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  username TEXT NOT NULL UNIQUE,
  password TEXT NOT NULL
);

Todos Table

CREATE TABLE todos (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER,
  task TEXT NOT NULL,
  completed BOOLEAN NOT NULL DEFAULT 0,
  FOREIGN KEY (user_id) REFERENCES users(id)
);

🧪 Testing

You can test the API endpoints using the included test.rest file with the REST Client extension in VS Code, or use tools like Postman or curl.

Example Registration Request

POST http://localhost:3000/auth/register
Content-Type: application/json

{
  "username": "your-username",
  "password": "your-password"
}

🔒 Security Features

• Password Hashing: All passwords are hashed using bcrypt with salt rounds
• JWT Authentication: Secure token-based authentication
• Input Validation: Server-side validation for all inputs
• SQL Injection Prevention: Prepared statements protect against SQL injection
• Foreign Key Constraints: Database integrity with proper relationships

📜 Available Scripts

• pnpm dev - Start development server with hot reload
• pnpm build - Build the project for production
• pnpm start - Start the production server
• pnpm check - Run TypeScript type checking

🤝 Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

📄 License

This project is licensed under the ISC License - see the LICENSE file for details.

👨‍💻 Author

JimmFly

• GitHub: @JimmFly

🙏 Acknowledgments

• Express.js community for excellent documentation
• SQLite for providing a lightweight database solution
• The TypeScript team for making JavaScript development more robust

---

⭐ If you found this project helpful, please give it a star!