ResultType

result_type.rb

module ResultType
  extend ActiveSupport::Concern

  module ClassMethods
    def define_type(type)
      define_method "#{type}?" do
        true
      end
    end
  end

  def method_missing(m, *args, &block)
    m.ends_with?("?") ? false : super
  end

  def respond_to_missing?(*args)
    true
  end
end

class BusinessesController
  def create
    result = Businesses::Profile.new.create(business_params)
    if result.success?
      redirect_to business_path(result.business)
    elsif result.special_case?
      redirect_to special_path
    else
      @business = result.business
      render :new, status: :unprocessable_entity
    end
  end
end

class Businesses::Profile
  def create(options)
    business = Business.new(options)
    if business.name == "Secret Business"
      SpecialCase.new
    elsif business.save
      Success.new(business)
    else
      Failure.new(business)
    end
  end

  private

  Success = Struct.new(:business) do
    include ResultType
    define_type :success
  end

  Failure = Struct.new(:business) do
    include ResultType
    define_type :failure
  end

  class SpecialCase
    include ResultType
    define_type :special_case
  end
end