A tour of dry-schema and dry-validation 1.0

The release of dry-validation 1.0 is just around the corner, so now is the perfect time to learn about its powerful approach to data validation.

If your Ruby app accepts external input (hint: yes, it does!), then this talk is for you. We’ll:

- Take a fresh look at why we validate in the first place
- Learn how it works (along with its new companion, dry-schema)
- Discover how it can improve our app architecture

You’ll leave with a couple of new (and newly API stable!) tools to use, as well as a new appreciation for the importance of data validation in any kind of application.

Transcript

1. A tour of dry-schema and dry-validation 1.0 ROROSyd, June 2019
2. @timriley
3. @timriley @icelab
7. @dry_rb
8. @dry_rb @icelab ✕
9. dry-schema dry-validation
10. dry-schema dry-validation 1.1.0 1.0.0
11. dry-schema dry-validation
12. dry-schema dry-validation Validation of data structures
13. dry-schema dry-validation Validation of data structures Validation using business rules
14. Piotr Solnica @_solnic_
15. Why validate?
18. !
19. !
20. ! "
21. dry-schema
22. dry-schema Focus on data structures & types
23. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end
24. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end
25. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end
26. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end
27. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end
28. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end Structure
29. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end Structure
30. require "dry/schema" schema = Dry::Schema.Params do required(:email).filled(:string) required(:age).filled(:integer) end Types Structure
31. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
32. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
33. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
34. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
35. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
36. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
37. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
38. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
39. result = schema.call( "email" => "jane@example.com", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"jane@example.com", :age=>35 # } errors={}>
40. result = schema.call( "email" => "", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"", :age=>35 # } # errors={ # :email=>["must be filled"] # }>
41. result = schema.call( "email" => "", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"", :age=>35 # } # errors={ # :email=>["must be filled"] # }>
42. result = schema.call( "email" => "", "age" => "35", ) # => #<Dry::Schema::Result{ # :email=>"", :age=>35 # } # errors={ # :email=>["must be filled"] # }>
43. Dry::Schema.Params do required(:email).filled(:string) required(:age).maybe(:integer) end
44. Dry::Schema.Params do required(:email).filled(:string) required(:age).maybe(:integer) end
45. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) end
46. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) end
47. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) required(:address).hash do required(:city).filled(:string) required(:postcode).filled(:string) end end
48. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) required(:address).hash(AddressSchema) end
49. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) required(:address).maybe do hash(AddressSchema) end end
50. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) required(:address).maybe do hash(AddressSchema) end required(:nicknames).array(:string) end
51. Dry::Schema.Params do required(:email).filled(:string) optional(:age).maybe(:integer) required(:address).maybe do hash(AddressSchema) end required(:nicknames).array(:hash) do required(:name).filled(:string) required(:date_granted).maybe(:date) end end
52. Dry::Schema.Params do optional(:age).filled(:integer) end
53. Dry::Schema.Params do optional(:age).filled(:integer) end
54. Dry::Schema.Params do optional(:age).filled(:integer) end Dry::Types["params.integer"]
55. Dry::Schema.Params do optional(:age).filled(:integer) end Dry::Types["params.integer"]["35"] # => 35
56. Dry::Schema.Params do optional(:age).filled(:integer) end Dry::Types["params.integer"]["35"] # => 35
57. Dry::Schema.Params do optional(:age).filled(:integer) end Dry::Types["params.integer"]["35"] # => 35
58. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
59. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
60. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
61. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
62. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
63. module Types include Dry.Types StrippedString = Types::String.constructor(&:strip) end schema = Dry::Schema.Params do optional(:name).filled(Types::StrippedString) end schema.("name" => " Clover ") # => #<Dry::Schema::Result{:name=>"Clover"} errors={}>
64. dry-types
65. dry-validation
66. dry-validation Focus on business rules
67. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end end
68. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end end
69. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end end
70. contract = EventContract.new contract.( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 22:00", ) # => #<Dry::Validation::Result{ # :name=>"ROROSyd", # :starts_at=>2019-06-11 18:00:00 +1000, # :ends_at=>2019-06-11 22:00:00 +1000 # } errors={}>
71. contract = EventContract.new contract.call( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 22:00", ) # => #<Dry::Validation::Result{ # :name=>"ROROSyd", # :starts_at=>2019-06-11 18:00:00 +1000, # :ends_at=>2019-06-11 22:00:00 +1000 # } errors={}>
72. contract = EventContract.new contract.call( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 22:00", ) # => #<Dry::Validation::Result{ # :name=>"ROROSyd", # :starts_at=>2019-06-11 18:00:00 +1000, # :ends_at=>2019-06-11 22:00:00 +1000 # } errors={}>
73. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end end
74. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
75. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
76. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
77. contract = EventContract.new contract.call( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 17:00", ).errors.to_h # => {:ends_at=>["must be after start time”]}
78. contract = EventContract.new contract.( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 17:00", ).errors.to_h # => {:ends_at=>["must be after start time”]}
79. contract = EventContract.new contract.( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "2019-06-11 17:00", ).errors.to_h # => {:ends_at=>["must be after start time"]}
80. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
81. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
82. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
83. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key(:ends_at).failure("must be…") end end end
84. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key(:ends_at).failure("must be…") end end end
85. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key(:times).failure("must be…") end end end
86. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key(:times).failure("must be…") end end end
87. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] base.failure("times must be…") end end end
88. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] base.failure("times must be…") end end end
89. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
90. class EventContract < Dry::Validation::Contract params do required(:name).filled(:string) required(:starts_at).filled(:time) required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do if value && value <= values[:starts_at] key.failure("must be after start time") end end end
91. contract = EventContract.new contract.( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "last drinks", ).errors.to_h # => {:ends_at=>["must be a time”]}
92. contract = EventContract.new contract.( "name" => "ROROSyd", "starts_at" => "2019-06-11 18:00", "ends_at" => "last drinks", ).errors.to_h # => {:ends_at=>["must be a time"]}
93. # => {:ends_at=>["must be a time"]}
94. # => {:ends_at=>["must be a time"]} class EventContract params do # … required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do # … end end
95. # => {:ends_at=>["must be a time"]} class EventContract params do # … required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do # … end end
96. # => {:ends_at=>["must be a time"]} class EventContract params do # … required(:ends_at).maybe(:time) end rule(:ends_at, :starts_at) do # … end end
97. class EventContract < Dry::Validation::Contract option :repo params do required(:slug).filled(:string) end rule(:slug) do unless repo.unique?(:slug, slug) key.failure("is already used") end end end contract = EventContract.new(repo: repo)
98. class EventContract < Dry::Validation::Contract option :event_repo params do required(:slug).filled(:string) end rule(:slug) do unless repo.unique?(:slug, slug) key.failure("is already used") end end end contract = EventContract.new(repo: repo)
99. class EventContract < Dry::Validation::Contract option :event_repo params do required(:slug).filled(:string) end rule(:slug) do unless event_repo.unique?(:slug, value) key.failure("is already used") end end end contract = EventContract.new(repo: repo)
100. class EventContract < Dry::Validation::Contract option :event_repo params do required(:slug).filled(:string) end rule(:slug) do unless event_repo.unique?(:slug, value) key.failure("is already used") end end end contract = EventContract.new(repo: repo)
101. class EventContract < Dry::Validation::Contract option :event_repo params do required(:slug).filled(:string) end rule(:slug) do unless event_repo.unique?(:slug, slug) key.failure("is already used") end end end contract = EventContract.new(event_repo: repo)
102. class EventContract < Dry::Validation::Contract params do required(:slug).filled(:string) end end
103. class BaseContract < Dry::Validation::Contract register_macro :slug_format do unless value.match?(/^[1-9a-z][1-9a-z-]+/) key.failure("must be slug formatted") end end end
104. class BaseContract < Dry::Validation::Contract register_macro :slug_format do unless value.match?(/^[1-9a-z][1-9a-z-]+/) key.failure("must be slug formatted") end end end
105. class BaseContract < Dry::Validation::Contract register_macro :slug_format do unless value.match?(SLUG_REGEXP) key.failure("must be slug formatted") end end end
106. class EventContract < BaseContract params do required(:slug).filled(:string) end rule(:slug).validate(:slug_format) end
107. class EventContract < BaseContract params do required(:slug).filled(:string) end rule(:slug).validate(:slug_format) end
108. class EventContract < BaseContract params do required(:slug).filled(:string) end rule(:slug).validate(:slug_format) end
109. class EventContract < BaseContract params do required(:slug).filled(:string) end rule(:slug).validate(:slug_format) end
110. class EventContract < BaseContract params do required(:slug).filled(:string) end rule(:slug).validate(:slug_format) end
111. dry-schema dry-validation
112. dry-schema dry-validation # #
113. Precise
114. Precise Flexible
115. Precise Flexible Fast
116. Better applications
117. Validate…
118. Validate… Controller params
119. Validate… Controller params In form objects
120. Validate… Controller params In form objects In “service” objects
121. Validate… Controller params Foreign data In form objects In “service” objects
122. Validate… Controller params Foreign data API requests/responses In form objects In “service” objects
123. @timriley / timriley.info @dry_rb / dry-rb.org @icelab / icelab.com.au Thank you!