Vending Machine Coding Challenge

The challenge

Design a vending machine that will take a number of coins and return change in the smallest number of coins possible. The machine should take 6 different coin types: 50p, 20p, 10p, 5p, 2p, 1p. There are 3 products: A - 95p, B - £1.26, C - £2.33.

Write tests for your solution using a testing framework of your choice.

The solution

It is a bit over-engineered and done for fun, feel free to submit your PRs with improvements.

Implemented features:

• Accepts coins
• Returns change in the smallest number of coins possible
• Accepts 6 different coin types: 50p, 20p, 10p, 5p, 2p, 1p
• When not picked up, the coins are stacked up in the coin return
• Unsupported coins are returned in the coin return
• It is possible to buy only one product in one transaction
• It is still possible to buy products when there are no coins in the machine, it will just keep the credit for the next transaction
• If all products are out of stock and your coins are trapped inside, you can still get them back by canceling the transaction

How to run

Install php 8.2 and composer, then run:

composer install

To run the tests:

composer test