after_spec.rb

describe Topic, "newest ordered by creation" do
  factory :first_topic,  :topic, :created_at => 3.days.ago
  factory :second_topic, :topic, :created_at => 2.days.ago
  factory :third_topic,  :topic, :created_at => 1.day.ago
  factory :fourth_topic, :topic, :created_at => 1.day.ago

  it "should be able to find the newest topics" do
    Topic.newest.map.should == [fourth_topic,
                                third_topic,
                                second_topic,
                                first_topic]
  end
end

before_spec.rb

describe Topic, "newest ordered by creation" do
  before do
    @first_topic  = Factory(:topic, :created_at => 3.days.ago)
    @second_topic = Factory(:topic, :created_at => 2.days.ago)
    @third_topic  = Factory(:topic, :created_at => 1.day.ago)
    @fourth_topic = Factory(:topic, :created_at => 1.day.ago)
  end

  it "should be able to find the newest topics" do
    Topic.newest.map.should == [@fourth_topic,
                                @third_topic,
                                @second_topic,
                                @first_topic]
  end
end

other_spec.rb

describe Topic do
  factory :project
  factory :account, :name => "My Account"
  factory(:user) { Factory(:user, :account => account) }
end