A simple RSpec test.

hash_spec.rb

describe Hash do
  context "with no keys" do
    subject { Hash.new }
    
    its(:size) { should == 0 }
  end

  context "including :a_key => 'a value'" do
    subject { {:a_key => 'a_value'} }
    
    its(:size) { should == 1 }
    it { should have_key :a_key }
  end
end