thoughtbot--shoulda-matchers/lib/shoulda/matchers/independent/delegate_method_matcher/stubbed_target.rb

module Shoulda
  module Matchers
    module Independent
      class DelegateMethodMatcher
        # @private
        class StubbedTarget
          def initialize(method)
            @received_method = false
            @received_arguments = []
            stub_method(method)
          end

          def has_received_method?
            received_method
          end

          def has_received_arguments?(*args)
            args == received_arguments
          end

          protected

          def stub_method(method)
            class_eval do
              define_method method do |*args|
                @received_method = true
                @received_arguments = args
              end
            end
          end

          attr_reader :received_method, :received_arguments
        end
      end
    end
  end
end