Ruby: Singelton example of wrapping child method from Parent

gistfile1.rb

module BaseService
  extend ActiveSupport::Concern

  class_methods do
    def call(*args, **keyword_args)
      service = new

      def service.result=(result)
        @result = result
      end

      def service.result
        @result
      end

      def service.success?
        @result.success?
      end

      def service.failure?
        @result.failure?
      end

      # This is the magic. We can add operations within the #tap block while
      # still retaining reference to the original instance of the object
      service.tap do |service_object|
        service_object.result = service.call(*args, **keyword_args)
      end
    end
  end
end

module Users
  class UpdatePassword
    include BaseService
    
    def call(stuff)
      # Do some stuff
      
      Success(:it_works)
    end
  end
end

# Note we use the class level `call` which utilzes the parent definition
# Allows us to utilize class level method as main caller and instance level as entrypoint for calling
# By doing this we can wrap the instance level method from the Parent and prepend/append operations around
# its result
Users::UpdatePassword.call("stuff")