Android code scalability

Transcript

1. Code Scalability
2. @diolor bit.ly/cd-scalability
3. Goal: Be ready for the next 20 people in your team
5. TEAM SIZE Android devs 0 3 6 9 Q1 2015 Q1 2016 Q1 2017 Q1 2018
6. What do we get paid to do?
7. Build new features, fast & with quality Iterate existing features, fast & with quality Build new features, fast & with quality Iterate existing features, fast & with quality
8. Increase development speed Reduce bugs FAST & WITH QUALITY
9. Unit test coverage 2% …BACK IN JANUARY 2016 Lints 700+ 2% -> 20% 700+ -> <20
10. HOW TO REDUCE LINTS? Build Passed Build Failed Build Skipped d Passed Build Failed Build Skipped Build Passed Build Failed Build Skipped Build Skipped Build Passed Strict CI Lint rules
11. How to reach 20% Unit test coverage?
12. MVC MODEL VIEW CHAOS
13. UI DOMAIN DATA BUSINESS RULES & LOGIC REMOTE & LOCAL DATA
14. DATA LAYER Get or set data to the backend (e.g. Api clients) Get or set data to our local storage (e.g. Databases)
15. API CLIENT VEHICLE REPOSITORY VEHICLE A VEHICLE B DATA LAYER
16. API CLIENT VEHICLE A VEHICLE B VEHICLE REPOSITORY DATA LAYER
17. VEHICLE A VEHICLE B API CLIENT VEHICLE REPOSITORY VEHICLES DATA LAYER
18. API CLIENT VEHICLE REPOSITORY DATABASE SHARED PREFS DATA LAYER
19. Business logic: Combine the data from the data layers No Android classes DOMAIN LAYER
20. LOGGED IN? FAVORITES FAVORITES INTERACTOR VEHICLES GAS STATIONS DOMAIN LAYER
21. FAVORITES INTERACTOR STATE OR ACTION DOMAIN LAYER FAVORITES
22. UI LAYER (MVP) VIEW (e.g. Activity)
23. PRESENTER VIEW (e.g. Activity) UI LAYER (MVP)
24. PRESENTER STATES ACTIONS VIEW (e.g. Activity) UI LAYER (MVP)
25. PRESENTER VIEW STATE VIEW (e.g. Activity) UI LAYER (MVP)
26. PRESENTER CALLBACKS VIEW (e.g. Activity) UI LAYER (MVP)
27. PRESENTER VIEW (e.g. Activity) ANDROID CODE PURE JAVA CODE UI LAYER (MVP)
28. UI DOMAIN DATA PRESENTERS VIEWS API CLIENTS REPOSITORIES INTERACTORS DATABASE PURE JAVA UNIT TESTABLE CODE
29. UI DOMAIN DATA PRESENTERS VIEWS API CLIENTS REPOSITORIES INTERACTORS DATABASE Interface between layers: RxJava 1 RxJava 2 Callbacks Different language
30. 20% unit test coverage
31. 2017: How about 40%?
34. PRESENTER INTERACTOR API A Activity API B
35. PRESENTER PRESENTER INTERACTOR INTERACTOR API A API B Activity
36. Activity onStart() onStop() onStart() onStop() onStart() onStop() PRESENTER PRESENTER INTERACTOR INTERACTOR API A API B
37. interface ! { fun onStart() fun onStop() } Hint: The compiler doesn’t like !. Will not compile.
38. class MyActivity : Activity() { }
39. class MyActivity : Activity() { val !s = ArrayList<!>() }
40. class MyActivity : Activity() { val !s = ArrayList<!>() override fun onStart() { !s.forEach { it.onStart() } } }
41. class MyActivity : Activity() { val !s = ArrayList<!>() override fun onStart() { !s.forEach { it.onStart() } } override fun onStop() { !s.forEach { it.onStop() } } }
42. class CustomView: FrameLayout( ) { }
43. class CustomView: FrameLayout( ) { } interface ! { fun onStart() fun onStop() }
44. class CustomView: FrameLayout( ), ! { override fun onStart() { } override fun onStop() { } }
45. class CustomView: FrameLayout( ), ! { override fun onStart() { "# call presenter start } override fun onStop() { "# call presenter stop } }
46. class CustomView: FrameLayout( ), ! { init { (context as MyActivity). !s.add(this) } override fun onStart() { "# call presenter start } override fun onStop() { "# call presenter stop } }
47. class CustomView: FrameLayout( ), ! { init { (context as MyActivity) . ! s.add(this) } override fun onStart() { "# call presenter start } override fun onStop() { "# call presenter stop } } class MyActivity : Activity() { val !s = ArrayList<!>() override fun onStart() { !s.forEach { it.onStart() } } override fun onStop() { !s.forEach { it.onStop() } } }
49. 100% tested business logic
50. What if they were submodules?
51. GRADLE BUILD TASKS
52. GRADLE BUILD TASKS
53. 20+ Submodules
54. 20+ Submodules
55. Centralize dependencies /buildSrc/
56. Centralize dependencies /buildSrc/src/main/java object versions { val kotlin ="1.2.30" }
57. Centralize dependencies /buildSrc/src/main/java object versions { val kotlin ="1.2.30" } object libraries { object kotlin { val reflect = "org.jetbrains.kotlin:kotlin-reflect:${versions.kotlin}" val stdlib = "org.jetbrains.kotlin:kotlin-stdlib:${versions.kotlin}" } }
58. Centralize dependencies dependencies { implementation libraries.kotlin.stdlib }
59. Scalable code?
60. REDUCE BUGS Reduce bugs Increase speed
61. Reduce bugs 40+% tested code | 100% business logic 99,99% crash free rate Isolated code which reduces domino bugfixes REDUCE BUGS
62. Low overlap between features Legacy code easier migrated If we had suddenly 20 devs, the code is completely isolated INCREASED SPEED
63. Thank you! @diolor