For version one: https://github.com/hanfak/shopping-cart-oo-calisthenics-java For version two: https://github.com/hanfak/shopping-cart-oo-calisthenics-java/tree/version2

Rules

See

http://codekata.com/kata/kata09-back-to-the-checkout/

Item | Unit Price | Special Price

A   |   50  |       3 for 130
B   |  30   |      2 for 45
C   |  20   |
D   |     15 |

Interface

co = CheckOut.new(pricing_rules)
co.scan(item)
co.scan(item)
    :    :
price = co.total

Code rules

The app must be created using the "Object Calisthenics" methodology by Jeff Bay

One level of indentation per method
Don’t use the ELSE keyword
Wrap all primitives and Strings
First class collections
One dot per line
Don’t abbreviate
Keep all entities small (50 lines)
No classes with more than two instance variables
No getters/setters/properties

Process

Apply TDD

1 - Write test
2 - Make it compile
3 - Watch it fail
4 - Make all test pass with minimum amount of code
5 - Refactor
    a - Use above code rules