rspec testing for associations.rb

  it "should have comments" do
    stock = Stock.create(:symbol => 'GOOG')
    stock.comments << Comment.new(:body => "First comment")
    stock.comments << Comment.new(:body => "Second comment")
    stock.should have(2).comments
  end

or

  it "should have comments" do
    stock = Stock.create(:symbol => 'GOOG')
    stock.should respond_to(:comments)
  end