This document discusses refactoring code and managing technical debt. It provides tips on when to refactor such as when code duplication, large classes or methods are detected. It also discusses balancing refactoring with timing in the development process. Code metrics are presented on various code bases to identify areas for refactoring such as files that are frequently changed or have high complexity. The importance of communication when refactoring and getting outside opinions is emphasized. Refactoring is described as improving code design without changing external behavior.

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. Ask for opinions from outside
(external or other teams)

40. “If you point of me, remember you have 3 fingers pointing at
you”
Pedro Vicente Gómez

41. 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.

42. Find meI am very social!
jorge@karumi.com
@flipper83
+JorgeJBarroso
Questions?