This is a simple and small exercise on how to use TDD on Ruby.
- Use Ruby (no RoR).
- Develop using TDD methodology (Test Driven Development).
- Use Git as SCM:
- After each test do a commit.
- Although there is no need to use Github it would be better. Local repository sent by email is an option too.
- No need to use a DB.
| Product code | Name | Price |
|---|---|---|
| GR1 | Green tea | £3.11 |
| SR1 | Strawberries | £5.00 |
| CF1 | Coffee | £11.23 |
The CEO is a big fan of buy-one-get-one-free offers and of green tea. He wants us to add a rule to do this.
The COO, though, likes low prices and wants people buying strawberries to get a price discount for bulk purchases. If you buy 3 or more strawberries, the price should drop to £4.50.
Our check-out can scan items in any order, and because the CEO and COO change their minds often, it needs to be flexible regarding our pricing rules.
The interface to our checkout looks like this (shown in ruby):
co = Checkout.new(pricing_rules)
co.scan(item)
co.scan(item)
price = co.totalImplement a checkout system that fulfills these requirements.
Basket: GR1,SR1,GR1,GR1,CF1
Total price expected: £22.45
Basket: GR1,GR1
Total price expected: £3.11
Basket: SR1,SR1,GR1,SR1
Total price expected: £16.61
Two classes have been defined: Checkout and PricingRule.