Say goodybe to bugs and anti-patterns with Error Prone - @JavaZone

Slides from my talk at JavaZone.

2. 2

3. 3
Code quality and repetitive discussions1
Introduce Error Prone2
Using Error Prone in practice!3
Error Prone @ Picnic4
Agenda
Applying Error Prone rules within Picnic5

4. 4

5. 5
Code reviews and discussions

6. 6

7. 7
Tools
Google/google-java-format
Reformats Java source code to comply
with Google Java Style.
checkstyle/checkstyle
Helps programmers write Java code
that adheres to a coding standard.
spotbugs/spotbugs
A tool for static analysis to look
for bugs in Java code.
SonarSource/sonarqube
Continuous Inspection.

8. 8
Code quality and repetitive discussions1
Introduce Error Prone2
Using Error Prone in practice!3
Error Prone @ Picnic4
Agenda
Applying Error Prone rules within Picnic5

9. 9
Open-source static analysis
Compiler plugin
Powerful
500+ Error Prone checks
Complex
Error Prone
Google/error-prone
Catch common Java mistakes
as compile-time errors

10. 10
Refaster
Examples from: http://errorprone.info/docs/refaster
Define refactorings with templates.
becomes

11. 11
Demo
Let’s demonstrate!
https://github.com/rickie/error-prone-demo

12. 12
Maven profile 1

13. 13
Maven profile 2

14. 14
Demo
Let’s demonstrate!
https://github.com/rickie/error-prone-demo

15. 15
Bug patterns
https://errorprone.info/bugpatterns

16. 16
Error Prone as superpower

17. 17

18. 18
Error Prone as superpower
Input:
Output:

19. 19
Code quality and repetitive discussions1
Introduce Error Prone2
Using Error Prone in practice!3
Error Prone @ Picnic4
Agenda
Applying Error Prone rules within Picnic5

20. 20
Roadmap to Enable Error Prone
Level 1:
Disable everything
Level 2:
Selectively enable a
few ERROR checks

Level 3:
Enable all default
ERROR checks

21. 21
Demo: introducing Error Prone in practice!
Let’s demonstrate!

22. 22

23. 23
Roadmap to Enable Error Prone
Level 1:
Disable everything

Level 2:
Selectively turn on a
few ERROR checks

Level 3:
Turn on all default
ERROR checks

24. 24
Code quality and repetitive discussions1
Introduce Error Prone2
Using Error Prone in practice!3
Error Prone @ Picnic4
Agenda
Applying Error Prone rules within Picnic5

25. 25
Error Prone @ Picnic
70+ repositories
Common configuration
./patch.sh
Continuous Integration

26. 26

27. 27
Picnic open-sourced: Error Prone Support!
900+ Refaster rules
40+ Error Prone bug checks
Picnic-opinionated set of rules
Migrations
https://error-prone.picnic.tech

28. 28
Refaster rule

29. 29
Error Prone BugPattern

30. 30
Picnic’s Error Prone Support
Run Refaster rules
Test support
Improved reporting for Refaster
Documentation website

31. 31 https://error-prone.picnic.tech

32. 32
Code quality and repetitive discussions1
Introduce Error Prone2
Using Error Prone in practice!3
Error Prone @ Picnic4
Agenda
Applying Error Prone rules within Picnic5

33. 33
Applying Error Prone Support @ Picnic
Introducing:
-all Refaster rules

-all Error Prone checks

Approach
Perspective
https://error-prone.picnic.tech

34. 34
Applying Error Prone Support @ Picnic
70+ PRs spread over 50+ Java repositories

33.665 insertions (+) 31.281 deletions (-)

35. 35

36. 36

37. 37
Current state of Error Prone Support
People contributing ideas (from reviews)

50+ contributors

Stickers

Adoption

External adoption

38. 38
Picnic x Moderne
+

39. 39
Let’s create a Refaster rule!

40. 40
Conclusion
Two perspectives:
-Happy developers!

-Platform team or configuration
maintainers.

41. 41
join.picnic.app

42. 42
Unsure about next steps?
Feel free to reach out!

- error-prone.picnic.tech


- github.com/rickie/error-prone-demo - Demo code
Jan Kothe
Special thanks to:
Stephan Schroevers
[email protected]
github.com/Stephan202

My contact details:
[email protected]
github.com/rickie
rick_ossies