Notes CRUD API

Professional Node.js REST API for managing notes with comprehensive testing and interview-ready architecture

A production-quality CRUD API built with Express.js, featuring comprehensive input validation, error handling, and a robust test suite. Designed to demonstrate senior-level backend engineering skills.

✨ Features

• Complete CRUD Operations - Create, read, update, and delete notes
• Professional Architecture - Clean separation of concerns with layered design
• Comprehensive Validation - Input sanitization and detailed error messages
• Robust Error Handling - Proper HTTP status codes and structured responses
• High Test Coverage - 95%+ coverage with 46 comprehensive test cases
• Code Quality - ESLint integration with consistent coding standards
• In-Memory Storage - No external dependencies, perfect for demos
• CORS Support - Ready for frontend integration
• Health Monitoring - Built-in health check endpoint

🚀 Quick Start

Prerequisites

• Node.js ≥18.0.0
• npm ≥8.0.0

Installation

# Clone the repository
git clone <repository-url>
cd notes-crud-api

# Install dependencies
npm install

# Start the server
npm start

The API will be available at http://localhost:3000

Development Mode

# Start with auto-reload
npm run dev

📋 Available Scripts

Command	Description
npm start	Start the production server
npm run dev	Start development server with auto-reload
npm test	Run the complete test suite
npm run test:watch	Run tests in watch mode
npm run test:coverage	Run tests with coverage report
npm run lint	Check code quality with ESLint
npm run lint:fix	Fix ESLint issues automatically

🔗 API Endpoints

Base URL

http://localhost:3000

Method	Endpoint	Description	Status Codes
POST	/notes	Create a new note	201, 400
GET	/notes	Retrieve all notes	200
GET	/notes/:id	Retrieve a specific note	200, 404
PUT	/notes/:id	Update a note	200, 400, 404
DELETE	/notes/:id	Delete a note	200, 404
GET	/health	Health check	200

Request/Response Examples

Create a Note

curl -X POST http://localhost:3000/notes \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Meeting Notes",
    "content": "Discuss project timeline and deliverables"
  }'

Response (201 Created):

{
  "success": true,
  "data": {
    "id": "123e4567-e89b-12d3-a456-426614174000",
    "title": "Meeting Notes",
    "content": "Discuss project timeline and deliverables",
    "createdAt": "2024-01-15T10:30:00.000Z",
    "updatedAt": "2024-01-15T10:30:00.000Z"
  },
  "message": "Note created successfully"
}

Get All Notes

curl http://localhost:3000/notes

Response (200 OK):

{
  "success": true,
  "data": [
    {
      "id": "123e4567-e89b-12d3-a456-426614174000",
      "title": "Meeting Notes",
      "content": "Discuss project timeline and deliverables",
      "createdAt": "2024-01-15T10:30:00.000Z",
      "updatedAt": "2024-01-15T10:30:00.000Z"
    }
  ],
  "count": 1,
  "message": "Notes retrieved successfully"
}

Get Specific Note

curl http://localhost:3000/notes/123e4567-e89b-12d3-a456-426614174000

Update a Note

curl -X PUT http://localhost:3000/notes/123e4567-e89b-12d3-a456-426614174000 \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Updated Meeting Notes",
    "content": "Discuss project timeline, deliverables, and budget"
  }'

Delete a Note

curl -X DELETE http://localhost:3000/notes/123e4567-e89b-12d3-a456-426614174000

Error Responses

Validation Error (400)

{
  "success": false,
  "error": "Validation Error",
  "message": "Title is required and must be a non-empty string"
}

Not Found (404)

{
  "success": false,
  "error": "Not Found",
  "message": "Note not found"
}

🧪 Testing & Quality

Test Coverage

The project maintains 95%+ code coverage with comprehensive test scenarios:

• 46 test cases covering all CRUD operations
• Validation testing for all input scenarios
• Error handling for edge cases and failures
• Integration testing for middleware and server functionality
• Boundary testing for limits and constraints

# Run all tests
npm test

# Run with coverage report
npm run test:coverage

# Run tests in watch mode
npm run test:watch

Code Quality

# Check code quality
npm run lint

# Auto-fix issues
npm run lint:fix

See TESTING.md for detailed testing documentation and philosophy.

🎬 Demo Script

A complete demo script is provided to showcase all API functionality:

# Make the script executable
chmod +x demo.sh

# Run the complete demo (requires server to be running)
./demo.sh

The demo script demonstrates:

1. Health check
2. Creating multiple notes
3. Retrieving all notes
4. Getting a specific note
5. Updating a note
6. Deleting a note
7. Error handling scenarios

🏗️ Architecture

Project Structure

notes-crud-api/
├── src/
│   ├── app.js              # Express application setup
│   ├── server.js           # Server startup and configuration
│   ├── middleware/         # Custom middleware
│   │   ├── errorHandler.js # Global error handling
│   │   └── validateNote.js # Input validation
│   ├── models/             # Data models
│   │   └── Note.js         # Note entity
│   ├── routes/             # API route definitions
│   │   └── notes.js        # Notes CRUD endpoints
│   └── services/           # Business logic
│       └── notesService.js # Notes service layer
├── tests/                  # Test suites
│   ├── notes.test.js       # API endpoint tests
│   ├── server.test.js      # Server integration tests
│   └── setup.js            # Test configuration
├── demo.sh                 # Complete API demo script
├── TESTING.md              # Testing documentation
└── README.md               # This file

Design Principles

• Layered Architecture - Clear separation between routes, services, and models
• Error-First Design - Comprehensive error handling at every layer
• Validation-First - Input validation before processing
• Test-Driven Quality - High test coverage with meaningful assertions
• Professional Standards - ESLint, consistent naming, proper HTTP codes

🎯 Interview-Ready Highlights

This project demonstrates:

Technical Excellence

• ✅ RESTful API design with proper HTTP methods and status codes
• ✅ Comprehensive input validation and error handling
• ✅ Professional project structure and code organization
• ✅ High test coverage (95%+) with meaningful test cases
• ✅ Code quality enforcement with ESLint
• ✅ Modern Node.js and Express.js best practices

Senior-Level Patterns

• ✅ Layered architecture with separation of concerns
• ✅ Middleware pattern for cross-cutting concerns
• ✅ Service layer abstraction for business logic
• ✅ Comprehensive error handling strategy
• ✅ Professional testing methodology
• ✅ Clean, maintainable, and scalable code

Production Readiness

• ✅ Environment-based configuration
• ✅ Proper logging and monitoring (health check)
• ✅ CORS support for frontend integration
• ✅ Input sanitization and validation
• ✅ Graceful error responses
• ✅ Documentation and demo scripts

🛠️ Technology Stack

• Runtime: Node.js 18+
• Framework: Express.js 4.18+
• Testing: Jest 29+ with Supertest
• Code Quality: ESLint 8+
• UUID Generation: uuid 9+
• CORS: cors 2.8+

📄 License

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

🤝 Contributing

This is a portfolio/interview demonstration project. For suggestions or improvements, please open an issue or submit a pull request.

---

Built with ❤️ for demonstrating senior backend engineering skills