unit testing

http://haacked.com/archive/2009/07/14/law-of-demeter-dot-counting.aspx/
http://devblog.avdi.org/2011/07/05/demeter-its-not-just-a-good-idea-its-the-law/

> http://www.slideshare.net/jeresig/understanding-javascript-testing
>
>> http://www.slideshare.net/DragonBe/unit-testing-php-apps-with-php-unit
>> http://www.slideshare.net/nickokiss/unit-testing-best-practices
>> http://www.slideshare.net/RobertoCasadei/effective-unit-testing

http://martinfowler.com/articles/mocksArentStubs.html
http://java.dzone.com/articles/unit-testing-checklist

Story

1. I need an emergency light which turns on automatically as power goes off.
2. I need an emergency light which turns off automatically as power is restored.
3. The emergency light must be able to power a 40W bulb for 3 hours.

Components

- Light (40W)
- Battery (???)
- Mains power detector

Unit Testcases

## Light
    - With 40W input the bulb must work
    - With 50W inut the bulb must fail
## Battery
    - With a 40W load on the battery, it must power for 3 hours
    - With a 120W load on the battery, it must power for 1 hour
## Mains Power Detector
    - With primary (120v) and secondary power (40v) provided, the output must be 120v
    - With no primary and secondary power (40v) provided, the output must be 40v