What's coming in Rails 5.2, and sneak peek into Rails 6

The next minor version of Ruby on Rails is right around the corner! Let's look at those new features that are coming in the next few weeks to Rails 5.2, and sneak peek into those new features that will come in Rails 6.0, the next major release of Rails.

Presented at Great Western Rails #3 in Bristol, UK on March 21, 2018 and Tokyo Rubyist Meetup on Apr 4, 2018.

Transcript

1. What's coming in
   Rails 5.2
   and sneak peek into Rails 6
   #rails52
   

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2. Prem Sichanugrist
   @sikachu
   
   /sikachu
   #rails52
   

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4. Pull Request Link
   https://github.com/rails/rails/pull/25992
   #rails52
   

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5. #tag
   #rails52
   https://github.com/rails/rails/pull/25992
   

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6. 5.2
   #rails52
   

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7. New Features
   Custom Mailer Delivery Job
   H2 Early Hints
   Headless Chrome and Headless Firefox Support
   DSL for Configuring CSP Header
   Verbose Query Log
   One-Way Migration in change block
   Active Storage
   Built-in Redis Cache Store
   ActiveSupport::CurrentAttributes
   #rails52
   

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8. Improvements
   Recycle Cache Keys
   AEAD Encrypted Cookies
   Support pg 1.0
   Safer Raw SQL handling
   New Threshold for Cache Compression
   freeze_time
   Bootsnap in Default Gemfile
   #rails52
   

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9. Active Storage
   #rails52
   

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10. NEW
    Active Storage
    #rails52
    

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11. NEW
    Active Storage
    #rails52
    class User < ApplicationRecord
    # Associates an attachment and a blob. When the user
    # is destroyed they are purged by default (models
    # destroyed, and resource files deleted).
    has_one_attached :avatar
    end
    class AvatarsController < ApplicationController
    def update
    # params[:avatar] contains a
    # ActionDispatch::Http::UploadedFile object
    Current.user.avatar.attach(params.require(:avatar))
    redirect_to Current.user
    end
    end
    

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12. NEW
    Active Storage
    #rails52
    Direct Uploads
    

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13. NEW
    Active Storage
    #rails52
    # Sprockets (Asset Pipeline)
    //= require activestorage
    # Yarn/Webpacker
    import * as ActiveStorage from "activestorage"
    ActiveStorage.start()
    # View file
    <%= form.file_field :attachments, multiple: true,
    direct_upload: true %>
    

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14. NEW
    Active Storage
    Q: Should I switch to Active Storage from [___________]?
    #rails52
    

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15. NEW
    Active Storage
    Q: Should I switch to Active Storage from [___________]?
    A: Sure!*
    #rails52
    

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16. NEW
    Active Storage
    Q: Should I use Active Storage for my new project?
    #rails52
    

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17. NEW
    Active Storage
    Q: Should I use Active Storage for my new project?
    A: Yes.
    #rails52
    

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18. Recycle Cache Keys
    #rails52
    https://github.com/rails/rails/pull/29092
    

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19. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    

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20. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190013"
    

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21. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190013"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190025"
    

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22. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190013"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190025"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190102"
    

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23. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190013"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190025"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190102"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190130"
    

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24. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1-20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190013"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190025"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190102"
    post.update!({ ... })
    post.cache_key #=> "post/1-20180320190130"
    

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25. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/3-20180319190000"
    "post/5-20180317014200"
    Redis
    

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26. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/1-20180320190013"
    "post/3-20180319190000"
    "post/5-20180317014200"
    Redis
    

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27. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/1-20180320190025"
    "post/1-20180320190013"
    "post/3-20180319190000"
    "post/5-20180317014200"
    Redis
    

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28. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/1-20180320190102"
    "post/1-20180320190025"
    "post/1-20180320190013"
    "post/3-20180319190000"
    "post/5-20180317014200"
    Redis
    

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29. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/1-20180320190130"
    "post/1-20180320190102"
    "post/1-20180320190025"
    "post/1-20180320190013"
    "post/3-20180319190000"
    "post/5-20180317014200"
    Redis
    

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30. ♻
    #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    

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31. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190000"
    

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32. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190013"
    

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33. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190000"
    post.update!({ ... })
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190013"
    post.update!({ ... })
    post.cache_key #=> "post/1"
    post.cache_version #=> "20180320190025"
    

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34. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    "post/1"
    "post/3"
    "post/5"
    Redis
    

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35. #rails52
    https://github.com/rails/rails/pull/29092
    Recycle Cache Keys
    config.active_record.cache_versioning = true
    

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36. AEAD Encrypted Cookies
    #rails52
    https://github.com/rails/rails/pull/28132
    

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37. AEAD
    Authenticated Encryption with Associated Data
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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38. Rails 4
    AES in CBC mode with HMAC using SHA1
    
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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39. Rails 4
    AES in CBC mode with HMAC using SHA1
    
    Rails 5.2
    AES-GCM
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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40. Benefits of AES-GCM
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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41. Benefits of AES-GCM
    Faster encryption/decryption
    
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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42. Benefits of AES-GCM
    Faster encryption/decryption
    
    Shorter ciphertext
    #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    

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43. #rails52
    https://github.com/rails/rails/pull/28132
    AEAD Encrypted Cookies
    config.action_dispatch.
    use_authenticated_cookie_encryption = true
    

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44. H2 Early Hints Support
    #rails52
    https://github.com/rails/rails/pull/30744
    

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45. Rails 5.2 + Puma + h2o
    #rails52
    https://github.com/rails/rails/pull/30744
    H2 Early Hints Support
    

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46. #rails52
    https://github.com/rails/rails/pull/30744
    H2 Early Hints Support
    HTTP/1.1 103 Early Hints
    Link: ; rel=preload; as=style
    Link: ; rel=preload; as=script
    HTTP/1.1 200 OK
    Date: Tue, 20 Mar 2018 15:12:00 GMT
    Content-Length: 4200
    Content-Type: text/html; charset=utf-8
    Link: ; rel=preload; as=style
    Link: ; rel=preload; as=script
    

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47. #rails52
    https://github.com/rails/rails/pull/30744
    H2 Early Hints Support
    <%= preload_link_tag "application.css" %>
    type="text/css" />
    

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48. #rails52
    https://github.com/rails/rails/pull/30744
    H2 Early Hints Support
    http://eileencodes.com/posts/http2-early-hints/
    

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49. DSL for Configuring CSP Header
    #rails52
    https://github.com/rails/rails/pull/31162
    

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50. Content-Security-Policy
    Control access to content from a user-agent
    #rails52
    https://github.com/rails/rails/pull/31162
    DSL for Configuring CSP Header
    

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51. #rails52
    https://github.com/rails/rails/pull/31162
    DSL for Configuring CSP Header
    #config/initializers/content_security_policy.rb
    Rails.application.config.content_security_policy do |p|
    p.default_src :self, :https
    p.font_src :self, :https, :data
    p.img_src :self, :https, :data
    p.object_src :none
    p.script_src :self, :https
    p.style_src :self, :https, :unsafe_inline
    # Specify URI for violation reports
    # p.report_uri "/csp-violation-report-endpoint"
    end
    

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52. #rails52
    https://github.com/rails/rails/pull/31162
    DSL for Configuring CSP Header
    # Override policy inline
    class PostsController < ApplicationController
    content_security_policy do |p|
    p.upgrade_insecure_requests true
    end
    end
    

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53. MDN web docs
    https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
    #rails52
    https://github.com/rails/rails/pull/31162
    DSL for Configuring CSP Header
    

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54. Verbose Query Log
    #rails52
    https://github.com/rails/rails/pull/26815
    

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55. #rails52
    https://github.com/rails/rails/pull/26815
    Started GET "/news/popular" for ::1 at 2016-10-19 00:5
    Processing by NewsController#popular as HTML
    Version Load (57.3ms) SELECT "versions".* FROM "ve
    Verbose Query Log
    

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56. #rails52
    https://github.com/rails/rails/pull/26815
    Started GET "/news/popular" for ::1 at 2016-10-19 00:5
    Processing by NewsController#popular as HTML
    Version Load (57.3ms) SELECT "versions".* FROM "ve
    ↳ app/views/news/show.html.erb:9:in `_app_views_news
    Verbose Query Log
    

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57. #rails52
    https://github.com/rails/rails/pull/26815
    Started GET "/news/popular" for ::1 at 2016-10-19 00:5
    Processing by NewsController#popular as HTML
    Version Load (57.3ms) SELECT "versions".* FROM "ve
    ↳ app/views/news/show.html.erb:9:in `_app_views_news
    Verbose Query Log
    

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58. #rails52
    https://github.com/rails/rails/pull/26815
    config.active_record.verbose_query_logs = true
    Verbose Query Log
    

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59. ActiveSupport::CurrentAttributes
    #rails52
    https://github.com/rails/rails/pull/29180
    

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60. Subdomain.current
    Account.current
    #rails52
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    

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61. #rails52
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    class Subdomain < ApplicationRecord
    cattr_accessor :current #
    end
    class Account < ApplicationRecord
    def self.current
    $current_account #
    end
    end
    

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62. #rails52
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    # app/models/current.rb
    class Current < ActiveSupport::CurrentAttributes
    attribute :subdomain
    attribute :account
    end
    

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63. Current.subdomain
    Current.account
    #rails52
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    

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64. Thread-Isolated Storage
    Thread.current[_____]
    #rails52
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    

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65. #rails52
    
    https://github.com/rails/rails/pull/29180
    ActiveSupport::CurrentAttributes
    

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66. #rails52
    
    

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67. Built-in Redis Cache Store
    config.cache_store = :redis_cache_store
    #rails52
    https://github.com/rails/rails/pull/31134
    

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68. New Threshold for Cache Compression
    Automatically compress value > 1kB
    #rails52
    https://github.com/rails/rails/pull/31147
    

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69. freeze_time
    Shorthand for travel_to Time.current
    #rails52
    https://github.com/rails/rails/pull/29681
    

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70. Bootsnap in Default Gemfile
    Add gem "bootsnap" for current projects
    #rails52
    https://github.com/rails/rails/pull/29313
    

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71. Headless Chrome
    Headless Firefox
    #rails52
    https://github.com/rails/rails/pull/30876

    https://github.com/rails/rails/pull/31365
    

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72. #rails52
    https://github.com/rails/rails/pull/30876

    https://github.com/rails/rails/pull/31365
    driven_by :selenium, using: :headless_chrome
    driven_by :selenium, using: :headless_firefox
    Headless Chrome & Firefox
    

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73. Custom Mailer Delivery Job
    #rails52
    https://github.com/rails/rails/pull/29457
    

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74. #rails52
    https://github.com/rails/rails/pull/29457
    class MyMailer < ApplicationMailer
    self.delivery_job = MyCustomDeliveryJob
    end
    Custom Mailer Delivery Job
    

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75. 5.2
    #rails52
    

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76. 6.0
    #rails6
    

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77. #rails6
    >= 2.4.1
    

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78. .create_or_find_by
    Use Unique index to mitigate possible

    race condition in find_or_create_by
    https://github.com/rails/rails/pull/31989
    #rails6
    

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79. Person.pick(:name)
    Same as Person.pluck(:name).first
    https://github.com/rails/rails/pull/31941
    #rails6
    

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80. Goodbye ‚
    utf8 attribute no longer generated in form_tag by default
    https://github.com/rails/rails/pull/32125
    #rails6
    

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81. Goodbye–✓
    utf8 attribute no longer generated in form_tag by default
    https://github.com/rails/rails/pull/32125
    #rails6
    

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82. update_attributes → update
    update_attributes! → update!
    https://github.com/rails/rails/pull/31998
    #rails6
    

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83. Parallel Testing
    http://edgeguides.rubyonrails.org/testing.html#parallel-testing
    
    https://github.com/rails/rails/pull/31900
    #rails6
    

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84. Expanded rails routes
    https://github.com/rails/rails/pull/32130
    #rails6
    

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85. https://github.com/rails/rails/pull/32130
    #rails6
    Expanded rails routes
    $ rails routes --expanded
    --[ Route 1 ]------------------------------------------------------------
    Prefix | high_scores
    Verb | GET
    URI | /high_scores(.:format)
    Controller#Action | high_scores#index
    --[ Route 2 ]------------------------------------------------------------
    Prefix | new_high_score
    Verb | GET
    URI | /high_scores/new(.:format)
    Controller#Action | high_scores#new
    --[ Route 3 ]------------------------------------------------------------
    Prefix | blog
    Verb |
    URI | /blog
    Controller#Action | Blog::Engine
    [ Routes for Blog::Engine ]
    --[ Route 1 ]------------------------------------------------------------
    Prefix | cart
    Verb | GET
    URI | /cart(.:format)
    Controller#Action | cart#show
    

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86. 5.2
    6.0
    

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