📚 Library Management Server

The Library Management API is a backend system built with Express, TypeScript, and MongoDB (Mongoose). It manages books with schema validation, supports CRUD operations, enforces valid genres and unique ISBNs, and handles borrowing through Mongoose methods. Aggregation is used to summarize borrow data, providing an efficient, schema-driven solution for library systems.

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API: Link
Explanation: Video

🚀 Features

• Automatic copy deduction & availability status update
• Borrowed book summary via aggregation
• Filtering, sorting for books

📦 Technologies Used

• Node.js + Express
• TypeScript
• MongoDB + Mongoose
• Zod (for schema validation)
• dotenv
• ESLint + Prettier (for code quality)

🛠️ Project Setup

# 1. Clone the repository
git clone https://github.com/md-afsar-dev/Library-management-server
cd Library-management-server

# 2. Install dependencies
bun install

# 3. Set up environment variables
touch .env

.env Example:

PORT = 4000
DB_NAME = ******
DB_PASSWORD = *****

📂 Folder Structure

LIBRARY-MANAGEMENT-SERVER/
├── .vercel/                     # Vercel deployment configuration
├── dist/                        # Compiled TypeScript files
├── node_modules/                # Node.js dependencies
├── src/                         # Source code
│   ├── config/                  # Environment and DB config
│   ├── controllers/             # Request handlers
│   ├── middlewares/             # Custom Express middlewares (e.g., error handling)
│   ├── models/                  # Mongoose schemas and methods
│   ├── routes/                  # API route definitions
│   ├── services/                # Business logic layer
│   ├── tests/                   # Unit and integration tests
│   ├── types/                   # TypeScript custom types and interfaces
│   ├── validations/             # Zod schemas for request validation
│   ├── app.ts                   # Express app setup
│   └── server.ts                # Server entry point
├── .env                         # Environment variables
├── .gitignore                   # Git ignore rules
├── .prettierignore              # Prettier ignore rules
├── .prettierrc.json             # Prettier config
├── erdiagram.png                # ER diagram image
├── eslint.config.mjs            # ESLint configuration
├── bun.lock                     # bun lockfile
├── package.json                 # Project metadata and scripts
├── README.md                    # Project documentation
├── tsconfig.json                # TypeScript compiler config
└── vercel.json                  # Vercel project settings

📘 API Endpoints

Base URL

http://localhost:5000/api

1. Create a Book

POST /api/create-book

{
  "title": "The Theory of Everything",
  "image": "https://res.cloudinary.com/dz1fy2tof/image/upload/v1751522624/download_n8dmde.jpg",
  "author": "Stephen Hawking",
  "genre": "SCIENCE",
  "isbn": "9780553380163",
  "description": "An overview of cosmology and black holes.",
  "copies": 5,
  "available": true
}

2. Get All Books

GET /api/books?filter=SCIENCE&sortBy=createdAt&sort=desc&limit=5

Supports:

• filter (genre)
• sortBy (e.g., createdAt)
• sort (asc|desc)
• limit (number of items)

3. Get Book by ID

GET /api/books/:id

4. Update Book

PUT /api/edit-book/:id

{
  "copies": 50
}

5. Delete Book

DELETE /api/delete-book/:id

6. Borrow a Book

POST /api/borrow/:bookId

{
  "bookId": "64ab3f9e2a4b5c6d7e8f9012",
  "quantity": 2,
  "dueDate": "2025-07-18T00:00:00.000Z"
}

📌 Business Logic:

• Quantity must be less than or equal to available copies
• Deduct copies automatically
• If copies become 0, set available = false

7. Borrowed Books Summary

GET /api/borrow-summary

📌 Uses MongoDB Aggregation to return:

[
  {
    "book": {
      "title": "The Theory of Everything",
      "isbn": "9780553380163"
    },
    "totalQuantity": 5
  }
]

🔍 Validations

Book Schema

Field	Type	Required	Validation
image	string	Yes	Must be a valid URL string
title	string	Yes	—
author	string	Yes	—
genre	enum	Yes	One of: FICTION, NON_FICTION, SCIENCE, HISTORY, BIOGRAPHY, FANTASY
isbn	string	Yes	Must be a valid string (unique enforced in DB)
description	string	No	Optional field
copies	number	Yes	Must be an integer ≥ 0
available	boolean	No	Optional field, defaults to true if not provided

Borrow Schema

Field	Type	Required	Validation
bookId	ObjectId	Yes	Must be a valid book
quantity	number	Yes	Must be positive
dueDate	Date	Yes	Future date required

Author

Md Afsar Mahmud
Full Stack Developer
HackerRank • LinkedIn