TDD workshop - Vending machine

Purpose

This is material for our internal TDD quickstart workshop. It comes as maven project (mvn wrapper included).

Problem to solve

• VendingMachine has a single method List<BigDecimal> calculateChange(BigDecimal price, BigDecimal cashPaid)
• Your task is to provide implementation of calculating change. Return type is sorted List<BigDecimal> (e.g. change of 3.50 will be returned as 2.00, 1.00 and 0.50).
• In case the there is not enough money, throw an IllegalArgumentException with message "Not enough money!"

Workshop steps

1. Project setup
   • Add your own implementation of VendingMachine
   • Make changes in VendingMachineFactory that will return your implementation, instead of null
2. Think about the problem and about your solution in the next 3-5 minutes, write down your general idea or pseudo code (not in too much details)
3. All the test cases are marked with @Ignore. Remove that annotation one at a time respecting the red-green-refactor cycle.
4. Compare your solution with the one from the beginning
5. Bonus step: Refactor tests