things.rb

module Things
  TYPE_ONE = 'type_one'.freeze
  TYPE_TWO = 'type_two'.freeze
  TYPE_THREE = 'type_three'.freeze

  class ThingFactory
    class << self
      def call(type, args)
        case type
        when TYPE_ONE
          TypeOne.new(args)
        when TYPE_TWO
          TypeTwo.new(args)
        when TYPE_THREE
          TypeThree.new(args)
        end
      end
    end
  end

  class TypeOne
    def initialize(args)
      @args = args
    end

    def do_work
      # do something using @args
    end
  end

  class TypeTwo
    def initialize(args)
      @args = args
    end

    def do_work
      # do something using @args
    end
  end

  class TypeThree
    def initialize(args)
      @args = args
    end

    def do_work
      # do something using @args
    end
  end
end