Better rspec structure with subject & let blocks

better_card_spec.rb

#improved example
require 'spec_helper'

describe Card do
  subject do
    Card.new(card_type)
  end
  
  describe "#value" do  
    context "Two of Hearts" do
      let(:card_type) { "2H" }
      its(:value) { should == 2 }
    end
  
    describe "Face Cards" do  
    
      context "King of Clubs" do
        let(:card_type) { "KC" }
        its(:value) { should == 13 }
      end
  
      context "Queen of Clubs" do
        let(:card_type) { "QC" }
        its(:value) { should == 12 }
      end

      context "Jack of Hearts" do
        let(:card_type) { "JH" }
        its(:value) { should == 11 }
      end
    end
    
    context "Bad Value" do
      it "should raise StandardError" do
        expect { card = Card.new("ZZ") }.to raise_error(StandardError)
      end
    end
  end
end

original_card_spec.rb

# original example
require 'spec_helper'

describe Card do
  describe "#new" do
    describe "Two of Hearts" do
      it "has a value of 2" do
        card = Card.new("2H")
        card.value.should equal(2)
      end
    end

    describe "King of Clubs" do
      it "has a value of 13" do
        card = Card.new("KC")
        card.value.should equal(13)
      end
    end

    describe "Queen of Clubs" do
      it "has a value of 12" do
        card = Card.new("QC")
        card.value.should equal(12)
      end
    end

    describe "Jack of Clubs" do
      it "has a value of 11" do
        card = Card.new("JC")
        card.value.should equal(11)
      end
    end

    describe "Bad Value" do
      it "should raise StandardError" do
        expect { card = Card.new("ZZ") }.to raise_error(StandardError)
      end
    end
  end
end