[Sin City Ruby 2024] Seven deadly Rails anti-patterns

Developing web applications with Ruby on Rails is known to be hellishly productive. What’s the price of this deal? Let’s talk about design patterns leveraged by the framework responsible for increased productivity and at the same time often acclaimed for being anti-patterns.

Transcript

1. Callbacks core_ext Concerns Current Page refreshes Helpers @vars in views Seven deadly Rails anti-patterns Sin City Ruby 2024 Vladimir Dementyev Evil Martians ?
2. palkan_tula palkan 2 Rails anti-patterns Software design patterns and ideas employed and/or encouraged by the framework that make developers hellishly productive (but come with a risk of poor maintainability in the long term) the framework productive poor maintainability Deal with the Devil
4. palkan_tula palkan Rails Way 4
5. palkan_tula palkan 5 github.com/palkan
6. palkan_tula palkan 6 evilmartians.com
7. palkan_tula palkan 7
9. + palkan_tula palkan 9 Callbacks core_ext Concerns Current Page refreshes Helpers @vars in views
10. + palkan_tula palkan 10 Callbacks core_ext Concerns Current Page refreshes Helpers @vars in views
11. + palkan_tula palkan 11 Disclaimer: I'm actively using (almost) all seven Confession
12. Callbacks
13. + palkan_tula palkan X
15. “The deeper callbacks lie in the architecture layer hierarchy, the more dangerous they can be” –Me @ Layered Rails 15
16. palkan_tula palkan Callbacks 16 Channels Jobs Mailers Models Controllers ⚠
17. palkan_tula palkan 17 class User < ApplicationRecord end Maintainability
18. palkan_tula palkan 18 class User < ApplicationRecord before_validation :normalize_email end Maintainability
19. palkan_tula palkan 19 class User < ApplicationRecord before_validation :normalize_email after_create_commit :send_welcome_email end Maintainability
20. palkan_tula palkan 20 class User < ApplicationRecord before_validation :normalize_email after_create :generate_initial_project after_create_commit :send_welcome_email end Maintainability
21. palkan_tula palkan 21 class User < ApplicationRecord before_validation :slugify, on: :create before_validation :normalize_email after_create :generate_initial_project after_create_commit :send_welcome_email end Maintainability
22. palkan_tula palkan 22 class User < ApplicationRecord before_validation :slugify, on: :create before_validation :normalize_email after_create :generate_initial_project, after_create_commit :send_welcome_email after_create_commit :send_analytics_event after_commit :sync_with_crm end Maintainability
23. palkan_tula palkan 23 class User < ApplicationRecord before_validation :slugify, on: :create before_validation :normalize_email after_create :generate_initial_project, after_create_commit :send_welcome_email after_create_commit :send_analytics_event, if: :tracking_consent? after_commit :sync_with_crm end Maintainability
24. palkan_tula palkan class User < ApplicationRecord before_validation :slugify, on: :create before_validation :normalize_email after_create :generate_initial_project, unless: :admin? after_create_commit :send_welcome_email after_create_commit :send_analytics_event, if: :tracking_consent? after_commit :sync_with_crm end 24 Maintainability
25. + palkan_tula palkan 25 (De-)Normalization Essential side-effects (audit, etc.) Conditional Peripheral side-effects (third-party integrations, etc.) Model Callbacks
26. Concerns
27. “A concern is a module that you extract to split the implementation of a class in coherent chunks, instead of having one big class body.” –Xavier Noria 27 coherent chunks
28. palkan_tula palkan 28 class Account < ApplicationRecord include Account::Associations include Account::Validations include Account::Scopes include Account::Callbacks end Cohesion Maintainability
29. palkan_tula palkan Coherent Chunks 29 class Identity < ApplicationRecord include Accessor, Authenticable, Boxes, Clearance, Preapproval, Clipper, Creator, Eventable, Examiner, Filer, Member, PasswordReset, Poster, Reaching, Regional, TopicMerger end God-blessed concerns Maintainability
30. + palkan_tula palkan 30 No isolation (potential hidden/circular dependencies) Naming is hard (modules, methods) Complicated testing Many Modules Maintainability
31. + palkan_tula palkan Many 32 No isolation (potential hidden/circular dependencies) Naming is hard (modules, methods) Complicated testing Many callbacks Concerns Maintainability
32. Many Objects Maintainability
33. + palkan_tula palkan 34 Value objects Workflows (state machines) Associated models Store models Extracting Prefer objects over concerns... gem "active_record-associated_object" gem "store_model"
34. 35 codewithjason.com
35. + palkan_tula palkan 36 Associations Active Record extensions (e.g., soft deletion) Gluing associated objects and host models the Rails Way Concerning ...but remember to stay productive
36. palkan_tula palkan 37 module Account::Terminable def terminate purge_or_incinerate if terminable? end private def purge_or_incinerate purgeable? ? purge : incinerate end # def purge # def incinerate # ... end
37. palkan_tula palkan 38 class Account::Terminator def initialize(account) = @account = account def perform purge_or_incinerate if terminable? end private def purge_or_incinerate purgeable? ? purge : incinerate end # def purge # def incinerate # ... end
38. palkan_tula palkan 39 account.terminate #=> Rails-ish! Account::Terminator.new(account) .perform #=> Boooring...
39. palkan_tula palkan 40 class Account::Terminator def initialize(account) = @account = account def perform purge_or_incinerate if terminable? end private def purge_or_incinerate purgeable? ? purge : incinerate end # def purge # def incinerate # ... end
40. palkan_tula palkan 41 class Account class Terminator # ... end module Terminable def terminate = Terminator.new(self).perform end end
41. + palkan_tula palkan 42 Concerns to sweep complexity under the rug Concerns to provide Rails-ish interface and to integrate with Active Record Objects to truly isolate functionality Concerns
42. Helpers
43. + palkan_tula palkan 44 Bags of random methods Form a single module shared by all views Helpers # Did you know? config.action_controller.include_all_helpers = false
44. Current
45. 46 thevaluable.dev
46. + palkan_tula palkan 47 Keep the number of current attributes small Always use Current.set(..., &) Write as upper on the abstraction stack as possible Current Don't let currents take you under
47. @vars in views
48. 49 thevaluable.dev
49. + palkan_tula palkan 50 Instance variables in controller action templates are fine (show.html, etc.) Instance variables in partials Strict locals in partials Become friends with erb-lint @vars in views Be strict with them (but not too strict)
50. core_ext
52. + palkan_tula palkan X
53. + palkan_tula palkan 54 Learn them, not fight Adding your own lib/core_ext!* core_ext * Or start using refinements
54. Page refreshes
55. palkan_tula palkan Page refreshes 56 <%# locals: (conversations:, total_count:) -%> <%= turbo_stream.update "counter" do %> <%= render partial: "counter", locals: {total_count:} %> <% end %> <%= turbo_stream.append "items" do %> <%= render partial: "items", locals: {current_conversation: Current.conversation, conversations:} %> <% end %> <%= turbo_stream.update "scroll" do %> <%= render partial: "scroll", locals: {id: :conversations, scroll_url: conversation_action_path(operation: :scroll, page: next_page)} %> <% end %> <%= turbo_stream.update "list" do %> <%= render partial: "list", locals: {conversations:, total_count:, current_conversation: Current.conversation} %> <% end %>
56. palkan_tula palkan Page refreshes 57 broadcast_refresh_to(conversation)
57. + palkan_tula palkan Rails 58 <turbo-stream-source> <turbo-stream action="refresh"/> GEt /converstation/2024
58. + palkan_tula palkan Rails 62 <turbo-stream-source> <turbo-stream-source> <turbo-stream-source> <turbo-stream-source>
59. + palkan_tula palkan 65 class Conversation < ApplicationRecord # Triggers page refresh on EVERY # record update broadcasts_refreshes end Deadly Combo Callbacks meet page refreshes
60. + palkan_tula palkan 66 class Conversation < ApplicationRecord after_commit :broadcast_refresh_later, if: :should_broadcast? private def should_broadcast? # check changed attributes, # throttle, etc. end end Deadly Combo Be specific, ship Union Pacific selective updates
62. + palkan_tula palkan 68 <%= cable_ready_updates_for conversation, only: %w[topic members_count], debounce: 200 do %> <% # ... %> <% end %> Cable Ready? Is Hotwire really that hot?
63. + palkan_tula palkan 69 Beware of multi-user updates Beware of frequent updates SolidCache is not an accident Page refreshes
64. + palkan_tula palkan 70 Callbacks Concerns Helpers Core extensions The Seven Caution! Sharp knives, use responsibly Current @vars in views Page refreshes
65. 71 dev.37signals.com/series/code-i-like/
66. –Me @ Sin City Ruby 2024 “Hell is full of Rails applications trying to go against the Rails Way.” 72
67. Slides: evilmartians.com/events Twitter: @palkan_tula, @evilmartians Sin City Ruby 2024 Don't go to Hell