Allow use cases to work with do notation

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    use_cases (3.0.0)
+    use_cases (3.0.1)
       activesupport (>= 6.1.7)
       dry-matcher (>= 0.8.1)
       dry-monads (>= 1.0.0)

lib/use_cases/module_optins/validated.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require "dry/validation"
 require "dry/validation/contract"
 
 module UseCases

lib/use_cases/result.rb

@@ -10,9 +10,19 @@ def initialize(step, result)
       @result = result
     end
 
+    def method_missing(method, *args, &block)
+      return result.send(method, *args, &block) if result.respond_to?(method)
+
+      super
+    end
+
+    def respond_to_missing?(method, include_private = false)
+      result.respond_to?(method, include_private) || super
+    end
+
     def value
       return result if result_not_monad?
-      return nil if result_empty?
+      return if result_empty?
 
       result.success? ? result.value! : result.failure
     end
@@ -39,7 +49,7 @@ def nil?
     end
 
     def to_result
-      self
+      result
     end
 
     def result_empty?

lib/use_cases/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module UseCases
-  VERSION = "3.0.1"
+  VERSION = "3.0.2"
 end

spec/support/test_subjects/operation_calling_use_case.rb

@@ -0,0 +1,27 @@
+class OperationCallingUseCase
+  include Dry::Monads[:result]
+  include Dry::Monads::Do.for(:call)
+
+  def call
+    result = yield call_operation
+    Success(result)
+  end
+
+  private
+
+  def call_operation
+    operation = Operation.new
+    operation.call({})
+  end
+end
+
+# Path: spec/use_cases/steps/operation.rb
+class Operation
+  include UseCase
+
+  step :step_1
+
+  def step_1
+    Success(:step_1)
+  end
+end

spec/use_cases/result_spec.rb

@@ -0,0 +1,16 @@
+require 'spec_helper'
+
+RSpec.describe UseCases::Result do
+  describe 'self' do
+    context 'when used by a service using the do notation' do
+      let(:caller) do
+        require 'support/test_subjects/operation_calling_use_case'
+        OperationCallingUseCase.new
+      end
+
+      it 'works' do
+        expect(caller.call).to be_success
+      end
+    end
+  end
+end