Library Catalog Backend

A backend system for managing a library catalog built with NestJS and PostgreSQL. The application includes functionality for managing books, students, and borrowed records, with robust error handling, validation, and health checks.

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Features

• Book Management: Add, update, view, and delete books with key attributes like title, author, ISBN, and availability.
• Student Management: Manage student records, including creating, updating, viewing, and deleting student information.
• Borrowed Books Management: Borrow and return books, ensuring that the library tracks book availability and borrowed records.
• Health Checks: Monitor the application's health, uptime, and database connectivity.
• Error Handling: Unified error responses with meaningful messages and proper HTTP status codes.
• Validation: Comprehensive request validation using DTOs and class-validator.

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Technologies Used

• Framework: NestJS
• Database: PostgreSQL
• ORM: Prisma
• Validation: class-validator
• API Documentation: Swagger (optional setup)

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Getting Started

Prerequisites

• Node.js (v16 or higher)
• PostgreSQL
• npm or yarn

Installation

1. Clone the repository:

   git clone https://github.com/ricky-ultimate/bunkolink-backend
   cd bunkolink-backend

2. Install dependencies:

   npm install

3. Configure the environment:
   • Create a .env file in the project root with the following variables:

     DATABASE_URL=postgresql://<username>:<password>@<host>:<port>/<database>
     

4. Apply Prisma migrations:

   npx prisma migrate dev

5. Start the development server:

   npm run start:dev

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Endpoints

Endpoint	Method	Description
/v1/books	POST	Add a new book to the library.
/v1/books	GET	Retrieve a list of all books in the library.
/v1/books/:id	GET	Retrieve details of a specific book by its ID.
/v1/books/:id	PATCH	Update the details of a specific book by its ID.
/v1/books/:id	DELETE	Delete a specific book by its ID.
/v1/students	POST	Add a new student to the library system.
/v1/students	GET	Retrieve a list of all students.
/v1/students/:id	GET	Retrieve details of a specific student by their ID.
/v1/students/:id	PATCH	Update the details of a specific student by their ID.
/v1/students/:id	DELETE	Delete a specific student by their ID.
/v1/borrowed-books/borrow	POST	Borrow a book by providing the book ID and student ID.
/v1/borrowed-books/return/:id	POST	Return a borrowed book by providing the borrowed book ID.
/v1/borrowed-books	GET	Retrieve a list of all borrowed books, including student and book details.
/v1/health	GET	Retrieve the application health status, including uptime and database connectivity information.

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Error Handling

The application provides meaningful error messages with proper HTTP status codes:

• 404 Not Found: For non-existent records (e.g., trying to retrieve or delete a book that doesn’t exist).
• 400 Bad Request: For invalid input or operations (e.g., borrowing a book when no copies are available).
• 409 Conflict: For duplicate entries (e.g., adding a book or student with an existing unique attribute).

Example error response format:

{
  "statusCode": 404,
  "message": "Book with ID 42 not found.",
  "timestamp": "2024-12-18T12:00:00.000Z",
  "path": "/v1/books/42"
}

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Development

Running the Application

• Start the application in development mode:

  npm run start:dev

Running Tests

• Run unit tests:

  npm run test

• Run end-to-end tests:

  npm run test:e2e

Building the Application

• Build the application for production:

  npm run build