gistfile1.rb

describe Item do
  describe "total" do
    before do
      @item = Item.new
      @item.stub!(:calculate_total => 123)
    end

    it "returns the calculated total" do
      @item.total.should == 123
    end

    it "subsequent calls don't calculate the total, but still return the original result" do
      @item.total
      @item.should_not_receive(:calculate_total)
      @item.total.should == 123
    end
  end
end