Bookstore API

Note

This is a simplified coding exercise implementation. It is not production-ready code.

A small TypeScript + Express API implementing a multi-layered architecture:

• Routes
• Controllers
• Services
• Repositories (in-memory)
• Models
• Unit tests (Jest)

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Current Features

• Create Book endpoint (POST /books)
• In-memory data storage with:
  • ID uniqueness validation
  • ISO createdAt timestamps
• Find Book by ID endpoint (GET /books/:id)
• List/Filter Books endpoint (GET /books)
  • Filter by genre (exact match, case-insensitive)
  • Filter by title (partial match, case-insensitive)
  • Filter by author (partial match, case-insensitive)
  • Multiple filters with AND logic
• Update Book by ID endpoint (PATCH /books/:id)
• Delete Book by ID endpoint (DELETE /books/:id)
• Calculate Discounted Price endpoint (GET /books/discounted-price)
  • Get total discounted price for all books of a specific genre
• Unit tests for:
  • Controller layer
  • Service layer
  • Repository layer

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How to Run

npm install
npm run dev

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How to Test

npm test

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Architecture Notes

• ID is provided by the client (per specification).
• Repository uses an in-memory store for this coding exercise.
• Layers follow clean architecture:
  • Route → Controller → Service → Repository → Store
• Code is structured to allow easy migration to a real database later.

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Manual API Testing (Examples)

Create a Book

curl -i -X POST http://localhost:3000/books \
  -H "Content-Type: application/json" \
  -d '{
    "id": 1,
    "title": "Dune",
    "author": "Frank Herbert",
    "genre": "Sci-fi",
    "price": 200
  }'

Find a Book by ID

curl -i -X GET http://localhost:3000/books/1

Update a Book by ID

curl -i -X PATCH http://localhost:3000/books/1 \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Dune (Updated Edition)",
    "price": 250
  }'

Delete a Book by ID

curl -i -X DELETE http://localhost:3000/books/1

List All Books

curl -i -X GET http://localhost:3000/books

Filter Books by Genre

curl -i -X GET "http://localhost:3000/books?genre=Sci-Fi"

Filter Books by Title (partial match)

curl -i -X GET "http://localhost:3000/books?title=dune"

Filter Books by Author (partial match)

curl -i -X GET "http://localhost:3000/books?author=herbert"

Filter Books by Multiple Criteria

curl -i -X GET "http://localhost:3000/books?genre=Sci-Fi&author=asimov"

Calculate Discounted Price for a Genre

curl -i -X GET "http://localhost:3000/books/discounted-price?genre=Sci-Fi&discount=20"

Response:

{
  "genre": "Sci-Fi",
  "discount_percentage": 20,
  "total_discounted_price": 120
}

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