Structural Engineering in Ruby

Morning keynote at Birmingham on Rails in Birmingham, AL in January 31, 2020

https://birminghamonrails.com/

Transcript

1. View Slide

2. Village
   

   View Slide

3. Open landscape
   

   View Slide

4. Street
   

   View Slide

5. City
   

   View Slide

6. City
   

   View Slide

7. Crumbling street
   

   View Slide

8. Building maintenance
   

   View Slide

9. Big or Small?
   Stand up if in your codebase you…
   
   • have more than 50 models
   
   • have a class with more than a 1000 LOC
   
   • have an ActiveRecord model with more than 30 :has_many
   
   • can’t run your full test suite on your machine
   
   • can’t run your test suite on your machine in under 20
   minutes
   

   View Slide

10. Street
    

    View Slide

11. Structural Engineering
    in Ruby
    Stephan Hagemann
    

    View Slide

12. View Slide

13. The only thing that ultimately
    let’s you reign in complexity
    within one app are components
    

    View Slide

14. As a language, Ruby
    does not have
    components
    

    View Slide

15. Gems can act as
    components
    

    View Slide

16. …they work well
    

    View Slide

17. For Rails, the situation
    kinda sucks…
    

    View Slide

18. …but works ok
    

    View Slide

19. Let’s make it
    better!
    

    View Slide

20. View Slide

21. View Slide

22. View Slide

23. View Slide

24. View Slide

25. View Slide

26. View Slide

27. View Slide

28. View Slide

29. View Slide

30. View Slide

31. View Slide

32. View Slide

33. View Slide

34. View Slide

35. View Slide

36. View Slide

37. View Slide

38. View Slide

39. Just a normal Rails app

    with some extra structure…
    

    View Slide

40. View Slide

41. View Slide

42. Structural 

    Costs + Benefits
    

    View Slide

43. View Slide

44. Method
    2 LOC
    Costs
    Hide logic
    Benefits
    Allow
    
    Reuse
    

    View Slide

45. Class
    2 LOC
    Costs
    Bundle logic
    
    and data
    Benefits
    Allow
    
    Reuse
    

    View Slide

46. Namespace
    2 LOC
    Costs
    Prevent
    
    naming
    
    collisions
    
    in the global
    
    namespace
    Benefits
    Group 

    classes 

    and methods
    

    View Slide

47. Component
    

    View Slide

48. WHAT IS A
    COMPONENT?
    

    View Slide

49. Labeled Content
    +
    Explicit Dependencies
    

    View Slide

50. Labeled, Unique Content
    +
    Explicit, Directed, Acyclic
    Dependencies
    

    View Slide

51. @shageman cbra.info
    ?
    

    View Slide

52. @shageman cbra.info
    

    View Slide

53. @shageman cbra.info
    ?
    ?
    

    View Slide

54. Labeled, Unique Content
    +
    Explicit, Directed, Acyclic
    Dependencies
    

    View Slide

55. @shageman cbra.info
    

    View Slide

56. A depends on B …
    A
    B
    

    View Slide

57. thus B can not depend on A
    A
    B
    X
    

    View Slide

58. … and you can’t cheat
    A
    B
    X
    C
    

    View Slide

59. View Slide

60. View Slide

61. Structure Benefit Cost
    Method Allow reuse, 

    hide logic
    2
    Class Bundle logic and data, allow reuse 2
    Namespace Prevent naming collisions, group
    classes and methods
    2
    

    View Slide

62. Gem
    

    View Slide

63. Gem
    88 LOC
    Costs
    Create
    
    provably
    
    independent

    package of 

    code
    Benefits
    bundle gem awesome_lib
    Allow 

    Distribution
    

    View Slide

64. Gem + Engine
    528 LOC
    Costs
    Create
    
    provably
    
    independent

    package of 

    code with 

    Rails
    Benefits
    rails plugin new components/awesome_engine --full --mountable
    Allow 

    Distribution
    

    View Slide

65. Structure Benefit Cost
    Method Allow reuse, 

    hide logic
    2
    Class Bundle logic and data, allow reuse 2
    Namespace Prevent naming collisions, group
    classes and methods
    2
    Component Allow Distribution, Create provably
    independent package of code
    88
    Rails Component
    Allow Distribution, Create provably
    independent package of code with
    Rails
    528
    

    View Slide

66. View Slide

67. View Slide

68. ML
    predictor
    X
    

    View Slide

69. 1 component with 100 elements 1,267,650,600,228,230,000,000,000,000,000
    2 component with 50 elements 2,251,799,813,685,150
    4 component with 25 elements 134,217,624
    5 component with 20 elements 5,242,775
    10 component with 10 elements 10,130
    * assuming a lot of stuff, including complexity growing according to Reed’s law
    

    View Slide

70. Structure Benefit Cost
    Method Allow reuse, 

    hide logic
    2
    Class Bundle logic and data, allow reuse 2
    Namespace Prevent naming collisions, group
    classes and methods
    2
    Component Allow Distribution, Create provably
    independent package of code
    88
    Rails Component
    Allow Distribution, Create provably
    independent package of code with
    Rails
    528
    

    View Slide

71. View Slide

72. 2 LOC
    Costs
    

    View Slide

73. Structure Benefit Cost
    Method Allow reuse, 

    hide logic
    2
    Class Bundle logic and data, allow reuse 2
    Namespace Prevent naming collisions, group
    classes and methods
    2
    Component Allow Distribution, Create provably
    independent package of code
    88
    Rails Component
    Allow Distribution, Create provably
    independent package of code with
    Rails
    528
    

    View Slide

74. Let’s make it
    better!
    

    View Slide

75. Share the stories
    of your large app!
    

    View Slide

76. Reduce Rails component costs!
    

    View Slide

77. Improve CI/CD integrations
    

    View Slide

78. Fix cross-component 

    dependency versioning
    

    View Slide

79. Can we create 

    component extractors?
    

    View Slide

80. Street
    

    View Slide

81. Building maintenance
    

    View Slide

82. City
    

    View Slide

83. Futuristic skyscraper
    

    View Slide