ancaleuca / supermarket-kata

Implementation of supermarket kata found here

Prerequisites

• Java 8
• Maven

Running the tests

mvn clean test

Approach

Please note this is just part of the model of a real supermarket. My application assumes there are Products (with infinite stock) and several types of Promotions. I've also added a stubbed Basket that only calculates its total and discounted prices.

This kata is based on Uncle Bob's clean architecture. I've implemented inputs to the system as simple Transactions that emulate use cases.

The real challenge has been implementing flexible promotions. At the moment, the system supports:

• single-buy promotions, e.g. "Buy one and pay £4 less"
• multi-buy promotions where the discount is calculated over a set of products - e.g., "Buy 3 get 20% off"

I've used the strategy pattern to make the promotions flexible in terms of:

• applicability - i.e. how many products are needed for the promotion to apply
• discount - i.e. different types of discounts (like percent or value)

REST endpoints

For example for products:

Add a product: POST /supermarket/products

Remove a product: DELETE /supermarket/products/{sku}

Update a product: PUT /supermarket/products

Get a product: GET /supermarket/products/{sku}