📚 Simple-Library-Management-System-API-v2

A RESTful API for managing a books collection, built with Node.js, Express, and MongoDB. Includes advanced querying features and an interactive documentation UI served as a static frontend.

---

🚀 Features

• Full CRUD operations for books
• Advanced querying: filtering, sorting, field selection, and pagination
• Comparison operators: $gt, $gte, $lt, $lte, $in
• Environment-based error handling (development vs. production)
• Interactive API documentation UI (served as static HTML)
• ESLint + Prettier for consistent code style

---

🛠️ Tech Stack

Layer	Technology
Runtime	Node.js (ESM)
Framework	Express 5
Database	MongoDB via Mongoose 9
Query Parser	qs
Dev Tools	Nodemon, ESLint, Prettier
Config	dotenv

---

📁 Project Structure

├── server.js # Entry point, DB connection, process error handlers
├── app.js # Express app setup, middleware, routes
├── config.env # Environment variables (not committed)
├── package.json
├── eslint.config.js
├── .gitignore
│
├── controllers/
│ ├── bookController.js # CRUD handlers
│ └── errorController.js # Global error handler (dev/prod modes)
│
├── models/
│ └── bookModel.js # Mongoose Book schema
│
├── routes/
│ └── bookRoute.js # Book router
│
├── utils/
│ ├── apiFeatures.js # Filtering, sorting, field limiting, pagination
│ ├── appError.js # Custom operational error class
│ └── catchAsync.js # Async error wrapper
│
└── public/
├── index.html # Interactive API docs UI
├── index.js # Frontend fetch logic
└── style.css # UI styles

---

⚙️ Getting Started

Prerequisites

• Node.js v18+
• MongoDB Atlas account (or local MongoDB instance)

Installation

git clone https://github.com/your-username/books-api.git
cd books-api
npm install

Configuration

Create a config.env file in the root directory:

NODE_ENV=developmentPORT=3000DATABASE_URL=mongodb+srv://<USERNAME>:<PASSWORD>@cluster.mongodb.net/booksDATABASE_PASSWORD=your_password

Running the App

# Development
npm start
# Production
npm run start:prod

The server starts on http://localhost:3000 by default.

---

📖 API Reference

Base URL: /api/v1/books

Endpoints

Method	Endpoint	Description
GET	/api/v1/books	Get all books
GET	/api/v1/books/:id	Get a single book
POST	/api/v1/books	Create a new book
PATCH	/api/v1/books/:id	Update a book
DELETE	/api/v1/books/:id	Delete a book

---

Query Features

Filtering

GET /api/v1/books?year=1960
GET /api/v1/books?year[gt]=1950
GET /api/v1/books?year[gte]=2000
GET /api/v1/books?year[lt]=1900
GET /api/v1/books?year[lte]=2000
GET /api/v1/books?year[in]=1960,2003

Sorting

GET /api/v1/books?sort=title
GET /api/v1/books?sort=-year # descending
GET /api/v1/books?sort=author,year # multi-field

Default sort: year (ascending).

Field Selection

GET /api/v1/books?fields=title,author,year

Default fields returned: title, author, year.

Pagination

GET /api/v1/books?page=2&limit=5

• Default: page=1, limit=10
• Maximum limit: 20

---

Request Body (POST / PATCH)

{
"title": "The Great Gatsby",
"author": "F. Scott Fitzgerald",
"genre": ["fiction", "classic"],
"year": 1925,
"available": true
}

Book Schema

Field	Type	Required	Notes
title	String	✅	Trimmed, lowercased
author	String	✅	Trimmed, lowercased
genre	[String]	❌	Array of genre strings
year	Number	❌	Publication year
available	Boolean	❌	Defaults to true
createdAt	Date	auto	Mongoose timestamp
updatedAt	Date	auto	Mongoose timestamp

---

Response Format

Success

{
"status": "success",
"result": 10,
"data": {
"books": [...]
}
}

Error (development)

{
"status": "fail",
"message": "No book found with that ID",
"error": {},
"stack": "..."
}

Error (production)

{
"status": "fail",
"message": "No book found with that ID"
}

---

🧩 Error Handling

• AppError — custom error class with statusCode, status, and isOperational flag
• catchAsync — wraps async route handlers to forward errors to Express
• globalErrorsHandler — Express error middleware with two modes:
  • development: returns full error object + stack trace
  • production: returns clean message for operational errors; generic 500 for unexpected ones
• Handles CastError (invalid MongoDB ID) and duplicate key errors (code 11000)

---

🎨 Interactive Docs UI

The project serves a built-in interactive documentation page at:

http://localhost:3000

It lets you try every endpoint directly from the browser — including filtering, pagination, creating, updating, and deleting books — with live JSON responses.

---

🧹 Linting & Formatting

npm run lint # Check for ESLint issues
npm run lint:fix # Auto-fix ESLint issues
npm run format # Format with Prettier

---

📝 License

ISC