contracts: implement a couple of example integrations

Gemfile

@@ -10,3 +10,7 @@ gem "rake", "~> 13.0"
 gem "minitest", "~> 5.16"
 
 gem "rubocop", "~> 1.21"
+
+gem "activemodel", "~> 7.2"
+
+gem "dry-validation", "~> 1.10"

Gemfile.lock

@@ -6,9 +6,63 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
+    activemodel (7.2.0)
+      activesupport (= 7.2.0)
+    activesupport (7.2.0)
+      base64
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.3.1)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      logger (>= 1.4.2)
+      minitest (>= 5.1)
+      securerandom (>= 0.3)
+      tzinfo (~> 2.0, >= 2.0.5)
     ast (2.4.2)
+    base64 (0.2.0)
+    bigdecimal (3.1.8)
+    concurrent-ruby (1.3.4)
+    connection_pool (2.4.1)
+    drb (2.2.1)
+    dry-configurable (1.2.0)
+      dry-core (~> 1.0, < 2)
+      zeitwerk (~> 2.6)
+    dry-core (1.0.1)
+      concurrent-ruby (~> 1.0)
+      zeitwerk (~> 2.6)
+    dry-inflector (1.1.0)
+    dry-initializer (3.1.1)
+    dry-logic (1.5.0)
+      concurrent-ruby (~> 1.0)
+      dry-core (~> 1.0, < 2)
+      zeitwerk (~> 2.6)
+    dry-schema (1.13.4)
+      concurrent-ruby (~> 1.0)
+      dry-configurable (~> 1.0, >= 1.0.1)
+      dry-core (~> 1.0, < 2)
+      dry-initializer (~> 3.0)
+      dry-logic (>= 1.4, < 2)
+      dry-types (>= 1.7, < 2)
+      zeitwerk (~> 2.6)
+    dry-types (1.7.2)
+      bigdecimal (~> 3.0)
+      concurrent-ruby (~> 1.0)
+      dry-core (~> 1.0)
+      dry-inflector (~> 1.0)
+      dry-logic (~> 1.4)
+      zeitwerk (~> 2.6)
+    dry-validation (1.10.0)
+      concurrent-ruby (~> 1.0)
+      dry-core (~> 1.0, < 2)
+      dry-initializer (~> 3.0)
+      dry-schema (>= 1.12, < 2)
+      zeitwerk (~> 2.6)
+    i18n (1.14.5)
+      concurrent-ruby (~> 1.0)
     json (2.7.2)
     language_server-protocol (3.17.0.3)
+    logger (1.6.0)
     minitest (5.24.1)
     parallel (1.26.1)
     parser (3.3.4.2)
@@ -34,14 +88,20 @@ GEM
     rubocop-ast (1.32.0)
       parser (>= 3.3.1.0)
     ruby-progressbar (1.13.0)
+    securerandom (0.3.1)
     strscan (3.1.0)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
     unicode-display_width (2.5.0)
+    zeitwerk (2.6.17)
 
 PLATFORMS
   arm64-darwin-23
   ruby
 
 DEPENDENCIES
+  activemodel (~> 7.2)
+  dry-validation (~> 1.10)
   i_do_not_need_interactor!
   minitest (~> 5.16)
   rake (~> 13.0)

examples/activemodel_context.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require "bundler/inline"
+
+gemfile true do
+  source "https://rubygems.org"
+
+  gem "activemodel"
+  gem "i_do_not_need_interactor", github: "alessandro-fazzi/i_do_not_need_interactor"
+  gem "amazing_print"
+end
+
+require "active_model"
+require "amazing_print"
+
+class DoSomething # rubocop:disable Style/Documentation
+  include Interactor
+  include Interactor::Contract::ActiveModel
+
+  def call(ctx)
+    ctx[:done] = true
+  end
+
+  contract do
+    attribute :done, :boolean
+    attribute :foo, :string
+    validates :foo, presence: true
+  end
+end
+
+result = DoSomething.call
+if result.success?
+  ap result
+else
+  ap result.errors
+end

examples/dry_validation_context.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require "bundler/inline"
+
+gemfile true do
+  source "https://rubygems.org"
+
+  gem "dry-validation"
+  gem "i_do_not_need_interactor", github: "alessandro-fazzi/i_do_not_need_interactor"
+  gem "amazing_print"
+end
+
+require "dry-validation"
+require "amazing_print"
+
+class DoSomething # rubocop:disable Style/Documentation
+  include Interactor
+  include Interactor::Contract::DryValidation
+
+  def call(ctx)
+    ctx[:done] = true
+  end
+
+  contract do
+    params do
+      optional(:done).value(:bool)
+      required(:foo).value(:string)
+    end
+  end
+end
+
+result = DoSomething.call(done: false)
+if result.success?
+  ap result
+else
+  ap result.errors
+end

lib/i_do_not_need_interactor.rb

@@ -12,6 +12,7 @@ def pipe
       end
 
       def call(ctx = Context.new)
+        ctx = Context.new(**ctx) unless ctx.is_a?(Context)
         new.maybe_call(ctx)
         ctx
       end
@@ -21,6 +22,11 @@ def call(ctx = Context.new)
   def maybe_call(ctx = Context.new)
     return ctx if ctx.failure?
 
+    if respond_to?(:validate)
+      validate(ctx)
+      return ctx if ctx.failure?
+    end
+
     call(ctx)
     ctx.register(self)
 
@@ -49,6 +55,49 @@ def success? = errors.empty?
 
     def failure? = !success?
   end
+
+  module Contract
+    module ActiveModel # rubocop:disable Style/Documentation
+      def self.included(descendant) # rubocop:disable Metrics/MethodLength
+        class << descendant
+          def contract(&block)
+            @contract = Class.new do
+              include ::ActiveModel::API
+              include ::ActiveModel::Attributes
+              include ::ActiveModel::Validations
+
+              def self.model_name
+                ::ActiveModel::Name.new(self, nil, "temp")
+              end
+            end
+            @contract.class_exec(&block)
+          end
+        end
+      end
+
+      def validate(ctx)
+        self.class.instance_variable_get(:@contract).new(**ctx).validate!
+      rescue ::ActiveModel::ValidationError => e
+        ctx.errors << e.message
+      end
+    end
+
+    module DryValidation # rubocop:disable Style/Documentation
+      def self.included(descendant)
+        class << descendant
+          def contract(&block)
+            @contract = Class.new(::Dry::Validation::Contract)
+            @contract.class_exec(&block)
+          end
+        end
+      end
+
+      def validate(ctx)
+        validation_result = self.class.instance_variable_get(:@contract).new.call(ctx)
+        ctx.errors << validation_result.errors.to_h if validation_result.errors.any?
+      end
+    end
+  end
 end
 
 Interactor = IDoNotNeedInteractor unless Module.const_defined?("Interactor")

test/test_helper.rb

@@ -4,3 +4,7 @@
 require "i_do_not_need_interactor"
 
 require "minitest/autorun"
+
+require "active_model"
+
+require "dry-validation"

test/test_i_do_not_need_interactor.rb

@@ -60,6 +60,31 @@ def call(ctx)
     end
   end
 
+  class InteractorWithActiveModelContract
+    include Interactor
+    include IDoNotNeedInteractor::Contract::ActiveModel
+
+    def call(ctx); end
+
+    contract do
+      attribute :test
+      validates :test, presence: true
+    end
+  end
+
+  class InteractorWithDryValidationContract
+    include Interactor
+    include IDoNotNeedInteractor::Contract::DryValidation
+
+    def call(ctx); end
+
+    contract do
+      params do
+        required(:test)
+      end
+    end
+  end
+
   def test_that_it_has_a_version_number
     refute_nil ::IDoNotNeedInteractor::VERSION
   end
@@ -166,4 +191,16 @@ def test_with_proc_is_possible_to_simulate_an_around_hook_also_in_composition #
     assert_equal [7, 2, nil], outcome[:before_around]
     assert_equal [7, 2, 9], outcome[:after_around]
   end
+
+  def test_contract_active_model_integration
+    outcome = InteractorWithActiveModelContract.call
+
+    assert_equal ["Validation failed: Test can't be blank"], outcome.errors
+  end
+
+  def test_contract_dry_validation_integration
+    outcome = InteractorWithDryValidationContract.call
+
+    assert_equal [{ test: ["is missing"] }], outcome.errors
+  end
 end