gistfile1.rb

class Application
  def fact s
  end
end

module RFact
  def fact fact_as_string
    Application.new.fact fact_as_string
  end
end

describe RFact do
  let(:application) { stub }

  describe "#fact" do
    it "should call fact on a new Application object" do
      cls = Class.new
      cls.send(:include,Rfact)
      obj = cls.new

      Application.should_receive(:new).and_return application
      application.should_receive(:fact).with("x")
      obj.fact "x"
    end
    
    it "calling it twice should use the same application object" do
      cls = Class.new
      cls.send(:include, RFact)
      obj = cls.new

      Application.should_receive(:new).once
      cls.fact "x"
      cls.fact "y"
    end
  end
end