Surviving to a Legacy Codebase - Voxxed Days Ticino Edition

Surviving a legacy codebase: tactics and tools to keep the right path

We will show you how to regain control of a legacy codebase written in Java. This codebase (https://github.com/xpepper/fifty-shades-of-legacy-goose-game/tree/master/goose-game-two) shows some classic design problems but more than that, badly expresses the domain of the problem we want to solve. During the session we will tackle the code the XP way: it will be a live refactoring in pair programming; we will show how the quality and expressiveness of the code can be progressively improved if we apply some good development practices with the help of some effective tools.

Made by Paolo D'Incau and Pietro Di Bello

Transcript

1. Surviving to a legacy codebase How we take back control of legacy codebases
2. Pietro Di Bello @pierodibello Paolo D’Incau @pdincau
3. What is legacy code?
4. “Code without tests.” Michael Feathers
5. “Valuable code that we feel afraid to change.” J.B. Rainsberger
6. Welcome to Board Games Sagl…
7. Surviving principle #1: understand the context of your software
8. Go talk with the business
9. The business of Board Game Sagl know that…
10. Users complain about a bug and we are losing customers and reputation!
11. In a few weeks one of our key gaming policies will change…
12. Let’s open the project and start gaining confidence
13. Surviving principle #2: maximize safety ⛑
14. Move carefully and take tiny steps
15. Remember to keep the focus on what matters
16. Remember the boy scout rule #1
17. Reduce the cognitive load
18. Slowly expand your sphere of control on the codebase
19. Surviving principle #3: focus on the flow of the money
20. Surviving principle #4: follow the flow of the bugs
21. To summarise…
22. “The journey of a thousand miles begins with one step.” Lao Tzu
23. Refactoring should be driven by real and emergent needs
24. www.xpeppers.com /xpepperssrl @xpeppers
25. Have fun with the Goose Game: https://github.com/xpepper/fifty-shades- of-legacy-goose-game/