/library-rest-api

Primary LanguageJavaScript

A RESTful API server for a library

This server is created with Node.js, Express and MongoDB. It could be implemented with a relational DB (as mentioned below), but for the sake of fast development and due to no data relationships - MongoDB has been chosen.

Assumptions

  • Each book is unique. No multiple books with the same name exist in the system.
  • When reserving a book, a person's name must be provided.
  • When checking out a book, a person's name must be provided.
  • A book can be checked out only if it was not reserved OR if it was reserved by that same person (look up by name)

Potential improvements

  • Have users registered in the system, so reserving/checking out actions can be tied to real user ids, instead of plain text names
  • Use an RDBMS, thus all relationships between users and books they reserved/checked out can be stored as separate entities (in separate tables, related to books/users tables via foreign keys)
  • Add logging
  • Add unit/integration tests

System Requirements

  • Node.js version 6.* or higher
  • MongoDB version 3.* or higher

Usage

Installing dependencies:

npm install

Before starting the server, make sure you seed the database with some books:

cd utils
node seed-db

Note: DB seed script will not cleanup the DB prior to seeding. So if you run it multiple times, it will duplicate the books which are already in DB.

Starting the server:

# make sure you are in the root project directory
npm start

API

There are 4 API endpoints, defined below. Using POST for checking in/out and reserving is not really a RESTful approach in this current implementation. POST requests are supposed to be creating a new entity, whereas we are updating the book document in DB (thus a PATCH request would be more appropriate in this case). However, eventually, I would slightly re-design the backend, so each checkin/reservation are actual entities (relationships between users and books). In that case POST would be a legitimate method for checkin/checkout/reserve operations, since it would be creating those relationships.

GET /search/:bookTitle

Searches all books, which match the bookTitle. Expects a book title to be passed as GET param.

example request

$ curl http://localhost:3000/search/house

response

{
  "status":200,
  "books":[
    {
       "_id":"5a065dc8b15c0666543c0df4",
       "name":"Thanks, Obama: My Hopey, Changey White House Years",
       "author":"David Litt"
    },
    {
       "_id":"5a065dc8b15c0666543c0df8",
       "name":"The Golden House",
       "author":"Salman Rushdie"
    },
    {
       "_id":"5a065dc8b15c0666543c0e15",
       "name":"Who Thought This Was a Good Idea?: And Other Questions You Should Have Answers to When You Work in the White House",
       "author":"Alyssa Mastromonaco"
    }
  ]
}

POST /book/:bookId/checkOut

Checks out a book. Expects a book id to be passed as GET param, and a userName as body.

example request

$ curl http://localhost:3000/book/<book_mongo_id>/checkout -X POST --data 'userName=John Doe'

response

{
  "status": 200,
  "message": "The book was checked out"
}

POST /book/:bookId/checkIn

Checks in a book. Expects a book id to be passed as GET param.

example request

$ curl http://localhost:3000/book/<book_mongo_id>/checkin -X POST

response

{
  "status": 200,
  "message": "The book was checked in"
}

POST /book/:bookId/reserve

Reserves a book. Expects a book id to be passed as GET param, and a userName as body.

example request

$ curl http://localhost:3000/book/<book_mongo_id>/reserve -X POST --data 'userName=John Doe'

response

{
  "status": 200,
  "message": "The book was checked out"
}