Write ruby code to change ruby code

Transcript

1. Write ruby code to change ruby code Richard Huang Xinmin

   Labs

2. About Me Founder at Xinmin Labs Full Stack Developer Open

   Source Enthusiast @flyerhzm

3. Problem

4. Hey, let’s use rspec new syntax for project A Yes,

   sure, I love the rspec new syntax

5. Hey, let’s use rspec new syntax for project B Hmmm…ok

6. Hey, let’s use rspec new syntax for project C Oh,

   no, I don’t want to repeat it again

7. Developers love upgrading and refactoring code

8. Developers hate changing code again and again

9. Automation

10. Metric Tools

11. Metric Tools • cane - fails your build if code

    quality thresholds are not met • reek - is a tool that examines Ruby classes, modules and methods and reports any code smells it finds. • rails_best_practices - is a tool to check the quality of rails code. • ……

12. Tell you what to do, but can’t do for you

13. IDE

14. IDE • can rename class / method / variable name

    • can extract methods • can ……

15. IDE • can’t customize

16. Based on text

17. Based on text Replace FactoryGirl.create with create ! $ sed

    -i '' 's/FactoryGirl.create/create/g' spec/**/*.rb

18. Based on text Replace FactoryGirl.create with create ! !

19. Based on text Hard to be accurate ! ! !

    !

20. Based on text Hard to convert complicated cases ! !

    ! !

21. Based on AST

22. What’s AST AST is short for Abstract Syntax Tree

23. What’s AST

24. Why AST It is much more accurate to parse ruby

    code.
25. None
26. None

27. How to use AST • ripper • ParseTree - https://github.com/seattlerb/parsetree

    • ruby_parser - https://github.com/seattlerb/ruby_parser • parser - https://github.com/whitequark/parser

28. How to use AST

29. Example transpec - https://github.com/yujinakayama/ transpec

30. None

31. Based on AST Accurate, but hard to write and read

32. Synvert https://github.com/xinminlabs/synvert

33. Demo http://xinminlabs.github.io/synvert/

34. None

35. Synvert • Add useful attributes to AST nodes ! •

    Provide DSL to parse and rewrite code

36. Attributes for AST node

37. Attributes for AST node

38. Attributes for AST node

39. Attributes for AST node Check out more attributes http://xinminlabs.github.io/synvert/rules/

40. DSL • within_file / within_files • with_node / within_node •

    if_exist_node / unless_exist_node • append / insert / insert_after / replace_with / remove • ……

41. DSL Check out more DSL http://xinminlabs.github.io/synvert/dsl/

42. None

43. Playground http://synvert-tools.herokuapp.com/

44. Snippets https://github.com/xinminlabs/synvert-snippets

45. Want more? • Fork and send pull request • Open

    issues on github • Hire us to refactor your project

46. Q&A ! Thank you