A discussion about unit testing strategies and test-driven development on the Android platform including: * Unit Testing & TDD Overview * Android Testing Framework * JUnit 4 + POJO Library * Robolectric

1. Android TDD
January 25, 2012
Chuck Greb
@ecgreb

2. Why Test?

3. Validate Requirements

4. Ensure Quality

5. Reduce Cost

6. Why Unit Test?

7. Test smallest possible units of code
(in isolation)

8. Makes refactoring easier
(regression suite)

9. Self-documenting code

10. Fakes
Mocks
Stubs

11. Why TDD?
(Test-Driven Development)

12. Improves Architecture

13. Reduced debugging time

14. Red -> Green -> Refactor

15. Tests must be fast!

16. Other kinds of tests?

17. Inverted Testing Pyramid

18. (Un-Inverted) Testing Pyramid

19. QA Job Security

20. Unit
Testing is
Awesome!!

21. Testing Approaches
● F@#% It!
● Manual
● Monkey Testing
● Android Testing Framework
● JUnit 4 + POJOs
● Robolectric
● Custom

22. Testing Approaches
● F@#% It!
● Manual
● Monkey Testing
● Android Testing Framework
● JUnit 4 + POJOs
● Robolectric
● Custom

23. Android Testing
Framework

24. JUnit 3 + Instrumentation

25. Android Testing Framework

26. Test Case Classes
● TestCase
● AndroidTestCase
● ActivityTestCase
● ActivityUnitTestCase
● ServiceTestCase
● ProviderTestCase2
● ActivityInstrumentationTestCase2

27. Android Mocks

28. HelloAndroidActivity

29. main.xml

30. StringBling

32. HelloAndroidActivityTest

33. Success!!!

34. Compile, dex, package, and install
two APKs on emulator or device

35. Additional Challenges
● Classes and methods declared final
● Lack of interfaces
● Non-public constructors
● Static methods

36. JUnit 4 + POJOs

37. HelloAndroidActivityJUnitTest

39. StringBling

40. StringBlingTest

41. Success!!!

42. But we want to test
ALL our code

43. Robolectric

44. Robolectric
Test-Drive Your Android Code

45. Shadow ObjectsShadow Objects

46. Shadow Objects in Action

47. View and Resource Loading

48. HelloAndroidActivityRobolectricTest

49. Success!!!

50. More fun with Shadows

51. Using ShadowImageView

52. Using ShadowActivity

53. Write your own
custom shadows

54. Contribute to Robolectric

55. Resources
● developer.android.com/guide/topics/testing
● junit.org
● pivotal.github.com/robolectric

56. Reading
● Robert C. Martin (Uncle Bob)
● Michael Feathers
● Kent Beck

57. Find your testing Zen

58. Chuck Greb
@ecgreb
http://ecgreb.com/blog
https://github.com/ecgreb/StringBling