Dungeons & Robots Part I (Androides y Mazmorras)

In this talk we show some tools and metrics to choose what is the best approach to refactor your application. Showing different techniques to prepare yourself before to start a refactor.

Transcript

1. Androides y mazmorras. Part I (dungeons & robots) Jorge Juan Barroso Carmona jorge@karumi.com @flipper83 +JorgeJBarroso Android expert
2. We embark on every project with a commitment to create something elegant, enduring and effective. That is our heartbeat. Our approach is uniquely simple and honest, we are a small dedicated software studio, delivering outstanding work. Karumi is the Rock Solid code software development studio.
6. Why go down the stairs
7. Adam Tornhill “When you see that I committed a bunch of buggy spaghetti last week, you know it’s because I’m a bad programmer, irresponsible and perhaps even a tad stupid. When you, on the other hand, deliver scrappy code (yes, I know - it’s a hypothetical scenario) you know it’s because you were close to a deadline, had to save the project or just intended it to be a prototype.”
8. Refactor is not destroy all your code
9. Refactor is not an Arcade Fire album.
10. Refactor is change the code and works on the same way
11. Timing is part of the development process
12. Programming is problem-solving. And human problem-solving requires a certain degree of experimentation
13. Architecture decay and code entropy
14. Ignorance and bad developers
15. Pedro Ureña “La deuda técnica es como tener una tarjeta de crédito. Tienes que devolver el dinero y los intereses. Si tiras siempre de la tarjeta de crédito, no vas a poder pagar los intereses y estarás en bancarrota.”
16. Explore the dungeon
17. “I wrote that about aesthetics in discussing when you apply refactorings. To some extent, the situations I describe in the refactoring guidelines are fairly vague notions of aesthetics. But I try to provide more guidance than just saying, "Refactor when the code looks ugly." I say, for instance, that duplicated code is a bad smell. I say that long methods are a bad smell. Big classes are a bad smell. ” Martin Fowler
18. Run away from intuition
19. Run away from trendy styles
20. Run away from me
21. Take decisions based on data
22. Searching for hotspots
23. number-of-commits,79 number-of-entities,2601 number-of-entities-changed,4582 number-of-authors,27 App Google IO 2014 Code-maat
24. Class sizes. Less size ~= Less responsibilities
25. File blank comment code ./android/src/main/java/com/google/samples/apps/iosched/ui/BaseActivity.java 203 175 1185 ./android/src/main/java/com/google/samples/apps/iosched/ui/SessionDetailActivity.java 178 111 995 ./third_party/disklrucache/src/test/java/com/jakewharton/disklrucache/DiskLruCacheTest.java 113 37 881 ./android/src/main/java/com/google/samples/apps/iosched/ui/SessionsFragment.java 147 106 875 ./android/src/main/java/com/google/samples/apps/iosched/provider/ScheduleProvider.java 78 128 842 ./android/src/main/java/com/google/samples/apps/iosched/ui/SessionLivestreamActivity.java 124 125 808 ./android/src/main/java/com/google/samples/apps/iosched/ui/MapFragment.java 181 166 635 ./third_party/disklrucache/src/main/java/com/jakewharton/disklrucache/DiskLruCache.java 92 215 623 ./android/src/main/java/com/google/samples/apps/iosched/provider/ScheduleContract.java 145 277 590 ./android/src/main/assets/licenses.html 85 12 583 Cloc
26. Watch out for classes that change frequently, it might be possible that a lot of people are working on it or it has too much responsibility
27. File n-revs entity,n-revs android/build.gradle, 14 doc/BUILDING.md, 13 README.md, 9 .travis.yml 9 Wearable/build.gradle, 6 build.gradle,6 android/src/com/google/android/apps/iosched/util/ImageWorker.java, 5 gradle/wrapper/gradle-wrapper.properties, 5 android/src/main/java/com/google/samples/apps/iosched/ui/BaseActivity.java, 5 android/src/main/res/values-it/strings.xml, 5
28. Code complexity
29. File num-lines total media max BaseActivity.java 1360 3332 2.45 8 SessionDetailActivity.java 1106 2898 2.62 9 MapInfoWindowAdapter.java 142 221 1.56 5
30. Temporal coupling Search getInstances()
31. File 1 File2 % couple average-rev SocialStreamFragment.java ImageFetcher.java 100 2 SocialStreamFragment.java ImageCache.java 100 2 ImageCache.java ImageFetcher.java 100 2
32. Code paths
33. Duplicated code DRY
34. Be careful with eternal changes
35. The dungeon master
36. Listens to everybody before making decisions Echo effect
37. Adjust the team and the communication process for the refactor
38. Ask for opinions from outside (external or other teams)
39. “If you point of me, remember you have 3 fingers pointing at you” Pedro Vicente Gómez
40. Bibliography They’re the cracks! Your Code as a crime scene. Adam Tornhill Working Effectively with legacy code. Michael Feathers Refactoring: Improving the Design of Existing Code. Martin Fowler. Workflows of Refactoring. Martin Fowler. OOP2014. Refactorizar a patrones. Xavi Gost. Refactoring: Where Do I start?. J. B. Rainsberger.
41. Find me I am very social! jorge@karumi.com @flipper83 +JorgeJBarroso Questions?