thoughtbot--shoulda-matchers/spec/support/helpers/confirmation_matcher_helpers.rb

module Helpers
  module ConfirmationMatcherHelpers
    def builder_for_record_validating_confirmation(options = {})
      RecordValidatingConfirmationBuilder.new(options)
    end

    class RecordValidatingConfirmationBuilder
      include ModelBuilder

      def initialize(options)
        @options = options
      end

      def model
        @_model ||= create_model
      end

      def model_name
        'Example'
      end

      def record
        model.new
      end

      def attribute_to_confirm
        :attribute_to_confirm
      end

      def confirmation_attribute
        :"#{attribute_to_confirm}_confirmation"
      end

      protected

      attr_reader :options

      private

      def create_model
        _attribute = attribute_to_confirm
        _options = options

        define_model(model_name, _attribute => :string) do
          validates_confirmation_of(_attribute, _options)
        end
      end
    end
  end
end