destroy_and_nil.rb

class ActiveSupport::TestCase

  protected
  
  # Use this to destroy ActiveRecord models you created and stored in instance variables.
  # Pass in the names of the instance variables:
  #
  #   teardown do
  #     destroy_and_nil(*%w(contact_details user product))
  #   end
  #
  def destroy_and_nil(*args)
    args.flatten.each do |ivar|
      unless instance_eval("@#{ivar}.nil?")
        if instance_eval("@#{ivar}").respond_to?(:destroy!)
          instance_eval("@#{ivar}.destroy!")
        else
          instance_eval("@#{ivar}.destroy")
        end
        instance_eval("@#{ivar} = nil")
      end
    end
  end

end