Slides from the Eclipse Summit Europe talk by Chris Aniszczyk and Paul VanderLei on October 28, 2009.

1. OSGi Versioning and Testing Chris AniszczykEclipseSource http://aniszczyk.org Paul VanderLei Band XI International

2. Sample Application: Toast Telematics-On-A-STick Sample from upcoming bookequinoxosgi.org Example project in EclipseRTwiki.eclipse.org/Toast 2 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

3. Toast Dependencies 3 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 EmergencyMonitor EmergencyServlet GPS Channel Airbag Log

4. get location EmergencyMonitor notify EmergencyServlet send HTTP GPS log Channel Log Toast: Emergency Scenario 4 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Airbag

5. Versioning: Overview Versioning Evolving API Tools Issues Summary 5 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

6. Define Versioning “Software versioning is the process of assigning either unique version names or unique version numbers to unique states of computer software.” Versioning is relative though… 6 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

7. Versioning: User Perspective 7 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Versioning is a marketing thing… User’s don’t really care about versions… Users just want to know if the version of the software they are running is current… e.g., Ubuntu Feisty Fawn – 7.04 Gutsy Gibbon – 7.10 Hardy Heron – 8.04

8. Versioning: Dev Perspective 8 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Version numbers are like dog tags* Primarily used in an event of emergency… *http://www.codinghorror.com/blog/archives/000793.html

9. OSGi Versions Dependencies are defined on the module and package level Import-Package Require-Bundle Ranges allow for flexibility Import-Package: org.easymock;version=[2.4.0,3.0.0) 9 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

10. OSGi Versioning Scheme major.minor.micro.qualifier major – An incompatible update; breaking API minor – A backward compatible update; API stable micro – A bug fix; no API changes qualifier – build date; lexigraphic Versions should encode compatibility* at the bundle and package level 10 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 *http://wiki.eclipse.org/Version_Numbering

11. Bundle Versions in Eclipse 11 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Notice how the version numbers don’t necessarily match the 3.6 release?

13. Log4j… 17 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

14. Commons Collections !@#$ 18 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 “Commons collections 3.0 is binary compatible with version 2.1 and 2.0 except for certain methods on one class . As the release was a major version, this is permitted, however it was unintentional and an error… the chosen solution is to provide a work around by releasing v2.1.1 and v3.1.” http://commons.apache.org/collections/compatibility.html

15. Developer Reaction… 19 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

16. Contracts are Important Good fences make for good neighbors! Binary compatibility* is important 20 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

17. Tools Binary compatibility is important Maintaining binary compatibility is complex Eclipse puts API on an altar… Since Eclipse 3.4, Eclipse uses tools to manage and evolve API… 21 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 *http://java.sun.com/docs/books/jls/second_edition/html/binaryComp.doc.html

18. PDE API Tools Assists developers in API maintenance by reporting API defects such as binary incompatibilities, incorrect bundle version numbers and API usage. Let’s see an example… 22 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

19. GPS Example using API Tools 23 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 We need height!

22. API Usage Report 30 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 22 GPS API References

23. API Usage Report 31 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 API Reference Details

24. Issues Getting proper version ranges correct is difficult if there’s no consistent semantics e.g., log4j case Not all bundles are versioned properly in repositories Tooling doesn’t cover packages yet… 32 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

25. Summary OSGi versions encode compatibility! Don’t treat bundle versions like a marketing number Scope your version ranges properly 33 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

26. Testing: Overview Good Practices Sample Application Unit Testing System Testing Remaining Issues 34 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

27. Good Practices: Testability Write your application as POJOs(plain-old-java-objects) No Service Trackers! Whiteboard Pattern is tricky Pay attention to dependencies Unit testing depends on getting this right 35 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

28. Good Practices: Testing Use Junit Use mock objects (EasyMock, jMock...) Minimize delays No human interaction Do TDD 36 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 “…I think that developers who can’t cope with any level of TDD shouldn’t be coding at all…”

29. Unit Testing: Overview Terminology Unit under test (UUT) Test harness Test each POJO on its own (no OSGi) Mock each dependency 37 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

30. get location EmergencyMonitor notify EmergencyServlet send HTTP GPS log Channel Log Toast: Emergency Scenario 38 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Airbag

31. UUT test harness Unit Testing: Example 39 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 get location EmergencyMonitor notify EmergencyServlet send GPS MockGPS Channel MockChannel Airbag MockAirbag Log

32. Unit Testing: Test Case Project Keep the test case in a separate project But POJO is not visible Solution: 40 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 fragment bundle

33. Unit Testing: Test Case Project 41 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Dependencies Junit & EasyMock dependencyinterfaces

34. Unit Testing: Test Case Code 42 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 createUUT createmock GPS

35. Unit Testing: Test Case Code 43 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 createmock airbag

36. Unit Testing: Test Case Code 44 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 createmock channel

37. Unit Testing: Test Case Code 45 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 runthe test

38. Unit Testing: Running 46 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

39. System Testing: Overview Test as much of system as possible OSGi is present Test full system flow Test bundles coming and going 47 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

40. UUT get location EmergencyMonitor notify EmergencyServlet send HTTP GPS ? log Channel test harness Log MockLog System Testing: Example 48 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 deploy Airbag MockAirbag verify TestCase

41. System Testing: Test Case Project 49 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Normal Plug-in Project declares 3 components

42. System Testing: Test Harness 50 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 hook for testing

43. System Testing: Test Harness 51 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 hook for testing

44. System Testing:Competing Programming Models PDE Junit test infrastructure uses Equinoxextensions Declarative Services uses OSGi services 52 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 VS

45. System Testing:PDE Junit Test Infrastructure Junit instantiates the test case as usual setup() testEmergency() Problem: no way to obtain: bundle context mock airbag mock log 53 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

46. System Testing:Declarative Services Instantiates the test case as a component DS dependency injection setAirbag(<our mock airbag>) setLog(<our mock log>) startup() Problem: This instance is never used by Junit! 54 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

47. System Testing: Test Case Code 55 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 instances share these DS invokes these DS invokes these DS invokes these ready to run test case

48. System Testing: Test Case Code 56 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 wait until DS has activated normaltest stop GPS bundle start GPS bundle

49. System Testing:Launch Configuration 57 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

50. Remaining Issues Still very tricky Not well-supported by PDE tooling Validation by logging is fragile 58 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0

51. Availability Get the slides: tinyurl.com/osgiVT Get the code: wiki.eclipse.org/Toast Get the book: equinoxosgi.org 59 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 Questions?

52. Sample Application:Emergency Scenario 60 OSGi Versioning and Testing | © Copyright 2009 EclipseSource & Band XI International; made available under EPL v1.0 EmergencyMonitor EmergencyServlet GPS Channel Airbag Log