article_spec.rb

require 'factory_girl'

class Article < Struct.new :headline
end

FactoryGirl.define do
  factory :article do
    headline "my headline"
  end
end

describe Article do
  it do
    article = FactoryGirl.build :article
    article.headline.upcase!
    article.headline.should == 'MY HEADLINE'
  end

  it do
    article = FactoryGirl.build :article
    article.headline.should == 'my headline'
  end
end