This document discusses test-driven development (TDD) and refactoring using the Gilded Rose kata exercise. It provides rules for TDD, such as only writing production code with a failing test and refactoring code after each test. Simple design principles are outlined, like revealing intention and avoiding duplication. Extreme object-oriented programming rules are also listed, like limiting indentation and properties. The goal is to practice TDD and refactoring skills through the Gilded Rose kata.

1. TDD, Refactoring
Using Gilded Rose Kata

3. http://blog.cleancoder.com/uncle-bob/2014/12/17/TheCyclesOfTDD.html
Focus
Confidence Progress

4. Simple Design Rules
- Passes the tests
- Reveals intention
- No duplication
- Fewest elements

5. Warm up?

6. TDD Rules
- You can’t write production code without a failing test
- You can’t have more than one failing test at a time
- You can’t write a new test until your code is properly
refactored

7. Simple Design
- Passes the tests
- Reveals intention
- No duplication
- Fewest elements

8. Gilded Rose Kata

9. bit.ly/gilded_rose_kata

10. Learnings/Feedback

11. Existing code?
Lets Start with refactoring

12. Learnings/Feedback

13. Extreme OOP

14. OOP Rules
- Use only one level of indentation per method
- Don’t use the else keyword
- Wrap all primitives and strings
- Use only one dot per line
- Don’t abbreviate

15. OOP Rules
- Keep all entities small.
- Don’t use any classes with more than two instance
variables.
- Use first-class collections.
- Don’t use any getters/setters/properties

17. Thank you!!!
@leenasn / leena@continuousdelivery.in
https://medium.com/@leenasn
https://medium.com/continuousdelivery

18. References
All the Little Things - Sandi Metz
Gilded Rose Kata - Emily Bache
Extreme OOP
Why getters and setters are evil?
I Pity The Fool Who Doesn't Write Unit Tests - Jeff Atwood
Why TDD - Naresh Jain