Linearly dependant tests in rspec

behavior.rb

module BehaviorDSL
  def behavior(name, &block)
    metadata[:description_args].push(name)
    refresh_description
    yield
    metadata[:description_args].pop
    refresh_description
  end

  private

  def refresh_description
    metadata[:description] = metadata[:description_args].join(" ")
    metadata[:full_description] = [metadata[:example_group][:full_description]].concat(metadata[:description_args]).join(" ")
  end

  def metadata
    RSpec.current_example.metadata
  end
end

RSpec.configure do |config|
  config.include BehaviorDSL
end

new_way_example_spec.rb

describe Hash do
  specify do
    @hash = Hash.new
    
    behavior "should set new keys properly" do
      @hash[:foo] = 'bar'
      @hash[:foo].should == 'bar'
    end
 
    behavior "overwrite old values with the same key" do
      @hash[:foo] = 'baz'
      @hash[:foo].should == 'baz'
    end
  end
end

old_way_example_spec.rb

describe Hash do
  before do
    @hash = Hash.new
  end
  
  it "should set new keys properly" do
    @hash[:foo] = 'bar'
    @hash[:foo].should == 'bar'
  end
 
  it "overwrite old values with the same key" do
    @hash[:foo] = 'bar'
    @hash[:foo].should == 'bar'
    @hash[:foo] = 'baz'
    @hash[:foo].should == 'baz'
  end
end