dsl.rb

require "minitest/autorun"

class Proxy
  module DSL
    module ClassMethods
      def option(name)
        define_method(name) do |value|
          tap do
            options[name] = value
          end
        end
      end
    end

    def self.included(base)
      base.extend(ClassMethods)
    end

    def options
      @__options ||= {}
    end
  end

  include DSL

  option :per_page
  option :page
end

describe Proxy::DSL do
  before do
    @proxy = Proxy.new
  end

  it "#page" do
    @proxy.page(2).options.must_equal(page: 2)
    @proxy.page(2).per_page(25).options.must_equal(page: 2, per_page: 25)
  end
end