Not the Rails Way. Again!

Ruby on Rails architectural practices.

Ruby Russia 2019, September 28, 2019.

Transcript

1. Not the Rails Way. Again! Igor Alexandrov, JetRockets Co-Founder
2. Igor Alexandrov github.com/igor-alexandrov twitter.com/igor_alexandrov instagram.com/igor_alexandrov
3. Tver.IO 11 meetups in 2019 > 80 people on each meetup Speakers from Evrone, Evil Martians, RAWG.io, Yandex, Mail.RU Audience > 2000 people • • • •
4. About since 2008 >= Rails 2.1 SmallTalk => Ruby => Crystal JetRockets CTO • • • •
5. JetRockets
6. The Rails Way?
7. The Rails Way
8. The Rails Way (Components) the champion of the startup hustle; ecosystem; community; • • •
9. Ecosystem acts_as_taggable •
10. Ecosystem acts_as_taggable acts_as_tree • •
11. Ecosystem acts_as_taggable acts_as_tree acts_as_commentable • • •
12. Ecosystem acts_as_taggable acts_as_tree acts_as_commentable acts_as_shopping_cart • • • •
13. Ecosystem acts_as_taggable acts_as_tree acts_as_commentable acts_as_shopping_cart … • • • • •
14. Community. How it was born? (2007) everyone came from somewhere (SmallTalk, Java, PHP); •
15. Community. How it was born? (2007) everyone came from somewhere (SmallTalk, Java, PHP); no developers who “were born with Rails”; • •
16. Community. How it was born? (2007) everyone came from somewhere (SmallTalk, Java, PHP); no developers who “were born with Rails”; we needed to be unique and have something to unite us; • • •
17. Community. How it was born? (2007) everyone came from somewhere (SmallTalk, Java, PHP); no developers who “were born with Rails”; we needed to be unique and have something to unite us; say “no” to “the architecture astronauts Java way” or the “PHP spaghetti way”; • • • •
18. Community. How it was born? (2007) “no” to everything Java-like; •
19. Community. How it was born? (2007) “no” to everything Java-like; XML → YAML; • •
20. Community. How it was born? (2007) “no” to everything Java-like; XML → YAML; patterns → ; • • •
21. Community. How it was born? (2007) “no” to everything Java-like; XML → YAML; patterns → ; DDD movement → ; • • • •
22. We’ve got ActiveRecord. We take the object from the database row and use it in all the three layers. Fat models or fat controllers? Whatever, let’s just not create new layers. » «
23. Success!
24. What we had in The Rails Way? ActiveRecord objects everywhere, including the views; •
25. What we had in The Rails Way? ActiveRecord objects everywhere, including the views; external gems used for most of the features; • •
26. What we had in The Rails Way? ActiveRecord objects everywhere, including the views; external gems used for most of the features; non-trivial logic with the combination of filters, callbacks, conditional validations and tons of ; • • •
27. What we had in The Rails Way? ActiveRecord objects everywhere, including the views; external gems used for most of the features; non-trivial logic with the combination of filters, callbacks, conditional validations and tons of ; metaprogramming; • • • •
28. What we had in The Rails Way? ActiveRecord objects everywhere, including the views; external gems used for most of the features; non-trivial logic with the combination of filters, callbacks, conditional validations and tons of ; metaprogramming; only 3 layers - Models, Views, Controllers. • • • • •
34. Let's dive deeper
35. 619 729 Fat Models # app/models/document.rb # Callbacks 621 622 before_validation :on => :create do 623 self.scorer = applicant 624 self.closing_status ||= 'likely' # … 728 # Class Methods
36. Logic in Views # app/views/shared/header.html.erb <% if current_user %> <%= current_user.name %> <% else %> Guest <% end %>
37. Gemfile Hell $ wc -l Gemfile 390 Gemfile
38. users_comments comments.select == params[:username] Controllers Hell class CommentsController < ApplicationController def posts = Post.all comments = posts.map(&:comments).flatten @user_comments = do |comment| comment.author.username end end end
39. Rails Helpers Retrieve data from the DB visible_comments_for(@article) ; •
40. Rails Helpers Retrieve data from the DB visible_comments_for(@article) ; no dependency tracking; • •
41. Rails Helpers Retrieve data from the DB visible_comments_for(@article) ; no dependency tracking; no inheritance; • • •
42. Rails Helpers Retrieve data from the DB visible_comments_for(@article) ; no dependency tracking; no inheritance; html tags generation. • • • •
43. Everything is so bad?
44. How do we live with this?
46. Standartization
47. Standartization Architecture •
48. Standartization Architecture Code Style • •
49. Standartization Architecture Code Style Libraries & workflow • • •
50. Architecture
51. TrailBlazer
52. TrailBlazer
53. Dry-rb
54. Query Objects Scope that interacts with more than one column and/or joins in other tables; •
55. Query Objects Scope that interacts with more than one column and/or joins in other tables; have single interface #call(relation) ; • •
56. Query Objects Scope that interacts with more than one column and/or joins in other tables; have single interface #call(relation) ; return ActiveRecord::Relation ; • • •
57. Query Objects Scope that interacts with more than one column and/or joins in other tables; have single interface #call(relation) ; return ActiveRecord::Relation ; accept query params as constructor arguments. • • • •
58. reduce_loan_officer_id if loan_officer_id Query Objects require 'dry-initializer' class Crm::ApplicationsSearch extend Dry::Initializer option :loan_officer_id, optional: true option # ... def call(application_relation) @query = application_relation @query = # ... @query end end
59. Service Objects
60. Web application — chain of services Request [*] [*] [*] [*] Response • • • • • •
61. Web application — chain of services Request Nginx Application Server (Unicorn/Puma) Rails Application DB Response • • • • • •
62. Web application — chain of services Request Nginx Application Server (Unicorn/Puma) Rails Application DB Response • • • • • •
63. Rails application — chain of services
64. Service Objects responsibilities Place to define complex actions; processes multiple steps and interactions; remove callbacks from ActiveRecord models; place to define validations. • • • •
65. Validator.check(contact).bind do |contact| Service Objects (AR validators) class Contacts::CreateContactFromDeal < BaseService def call(deal) contact = something_that_creates_contact(deal) contact.save! Success(contact) end end class Validator < ::ApplicationValidator validates :email, presence: true end end
66. Service Objects (dry-rb) class Leads::CreateLead # … def call(lead, params) params = yield validate(lead, params) lead = yield persist(lead, params) yield notify(lead) Success(lead) end # … end
67. yield Success(lead) Service Objects (dry-monads) class Leads::CreateLead # … def call(lead, params) params = validate(lead, params) lead = yield persist(lead, params) yield notify(lead) end # … end
68. Service Objects (dry-validation)
69. dry-validation Dry-schema to define reusable schemas; input sanitization, coercion and type-check; macros (beta); custom rules that don't break your head. • • • •
70. detect_contract(params[:source]).call(params) Service Objects (dry-validation) class Leads::CreateLead def call(lead, params) # … end def validate(lead, params) result = if result.success? Success(result.to_h) else Failure(…) end end end
71. ContactsContract HireUsContract Service Objects (dry-validation) class Leads::CreateLead # … class < Dry::Validation::Contract # … end class < Dry::Validation::Contract # … end end
72. case result Service Objects (controllers) class LeadsController < ApplicationController def create command = Lead::CreateLead.new result = command.(resource_lead, params[:lead]) when Dry::Monads::Success render #… when Dry::Monads.Failure(JetRockets::ValidationError) render #… when Dry::Monads.Failure render #… end end end
73. Service Objects (RSpec)
74. HireUsContract PostsContract Service Objects (RSpec) RSpec.describe Leads::CreateLead:: do subject(:command) do Leads::CreateLead::::HireUsContract.new end # operations end RSpec.describe Leads::CreateLead:: do # … end
75. Service Objects conventions Avoid NounServices (e.g. UsersService, ProductService ); •
76. Service Objects conventions Avoid NounServices (e.g. UsersService, ProductService ); be specific (e.g. Users::ForgotPassword ); • •
77. Service Objects conventions Avoid NounServices (e.g. UsersService, ProductService ); be specific (e.g. Users::ForgotPassword ); use namespaces based on domain concepts (e.g. /crm/documents/category/update_category ); • • •
78. Service Objects conventions Avoid NounServices (e.g. UsersService, ProductService ); be specific (e.g. Users::ForgotPassword ); use namespaces based on domain concepts (e.g. /crm/documents/category/update_category ); focus on readability of your call method; • • • •
79. Service Objects conventions Avoid NounServices (e.g. UsersService, ProductService ); be specific (e.g. Users::ForgotPassword ); use namespaces based on domain concepts (e.g. /crm/documents/category/update_category ); focus on readability of your call method; return results with state. • • • • •
80. Schema
81. Code Style
82. Code Style
83. Code Style
85. github.com/testdouble/standard
86. standard inherit_gem: standard: config/base.yml AllCops: Exclude: - 'bin/*' - 'tmp/**/*' …
87. standard Wrapper on top of RuboCop; can be used separately; can included into Rubocop configuration; includes only rubocop and rubocop-performance Cops configuration. • • • •
88. What to do with other Cops? rubocop-rails; rubocop-rspec; rubocop-i18n; • • •
89. Create your own gem with configuration
90. jetrockets-standard https:/ /github.com/jetrockets/jetrockets-standard https:/ /rubygems.org/gems/jetrockets-standard Also created similar packages for JS (ESLint, prettier) • • •
91. Company-wide "whitelist" of gems
92. Company-wide "whitelist" of gems AuthLogic Devise ActiveAdmin • • •
93. TrailBlazer?
94. No, it is still Rails With modular approach; •
95. No, it is still Rails With modular approach; with composition of services; • •
96. No, it is still Rails With modular approach; with composition of services; mature and stable; • • •
97. No, it is still Rails With modular approach; with composition of services; mature and stable; maintainable. • • • •
98. What to do right now? implement company/project-wide standard; •
99. What to do right now? implement company/project-wide standard; follow these standards; • •
100. What to do right now? implement company/project-wide standard; follow these standards; don't be afraid to experiment; • • •
101. What to do right now? implement company/project-wide standard; follow these standards; don't be afraid to experiment; start new project with Rails! • • • •
102. Books
103. Books
104. Links jetrockets.pro github.com/jetrockets github.com/igor-alexandrov