parent test

gistfile1.txt

## feed.rb
  validate :parent_id_cannot_be_this_feed

  def parent_id_cannot_be_this_feed
    if !parent_id.blank? and parent_id == id
      errors.add(:parent_id, "can't be this feed")
    end
  end

## feed_test.rb
  test "that a feed cannot be it's own parent" do
    feed = Feed.new(:name => "New",
                    :description => "A new feed.",
                    :group => groups(:rpitv),
                    :parent_id => :id)
    #assert feed.invalid?
    assert_not_equal feed.id, feed.parent_id
    assert feed.errors[:parent_id].any?
  end