added parent validation for #89

app/models/feed.rb

@@ -12,17 +12,24 @@ class Feed < ActiveRecord::Base
   #Validations
   validates :name, :presence => true, :uniqueness => true
   validates :group, :presence => true, :associated => true
-
+  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 Hierachy
   belongs_to :parent, :class_name => "Feed"
   has_many :children, :class_name => "Feed", :foreign_key => "parent_id"
   scope :roots, where(:parent_id => nil)
-  
+
   # Test if this feed is a root feed or not
   def is_root?
     parent_id.nil?
   end
-  
+
   # Collect a list of parent feeds.
   # Each feed the monkey stops as he climbs
   # up the tree.
@@ -31,8 +38,8 @@ def ancestors
     node, nodes = self, []
     nodes << node = node.parent while node.parent
     nodes
-  end  
-  
+  end
+
   # Collect recursive list of child feeds.
   # Every feed the monkey could stop by as he
   # climbs down a tree.
@@ -47,13 +54,13 @@ def descendants
     } unless node.children.empty?
     nodes
   end
-  
+
   # Figure out how deep in the tree
   # the current feed is.  0 = root
   def depth
     ancestors.count
   end
-  
+
   # The group of feeds who share a common parent.
   def self_and_siblings
     parent ? parent.children : Feed.roots
@@ -66,5 +73,5 @@ def self.subscribable(screen, field)
     subscriptions = Subscription.where(:screen_id => screen, :field_id => field)
     current_feeds = subscriptions.collect{ |s| s.feed }
     Feed.all - current_feeds
-  end  
+  end
 end

test/unit/feed_test.rb

@@ -13,83 +13,91 @@ def setup
     assert feed.errors[:name].any?
     assert feed.errors[:group].any?
   end
-  
+
   # The feed name must be unique
   test "feed is now valid without a unique name" do
     feed = Feed.new(:name => feeds(:service).name,
                     :description => "Another feed.",
                     :group => groups(:rpitv))
-                    
+
     assert feed.invalid?
     assert feed.errors[:name].any?
   end
 
 
   # Feed Hierachy Tests
-  
+
   # Verify the root scope returns all root feeds.
   test "feed root scope" do
     roots = Feed.roots
     roots.each do |feed|
       assert feed.is_root?
     end
   end
-  
+
   # A child feed should have a parent
   test "feed parent relationship" do
     assert_nil feeds(:announcements).parent
     assert_equal feeds(:boring_announcements).parent, feeds(:announcements)
   end
-  
+
   # A feed should have children
   test "feed child relationship" do
     assert feeds(:service).children.empty?
-    
+
     assert feeds(:announcements).children.include?(feeds(:boring_announcements))
     assert feeds(:announcements).children.include?(feeds(:important_announcements))
-    
+
     assert_equal feeds(:boring_announcements).children, [feeds(:sleepy_announcements)]
   end
-  
+
   # A root feed is_root?
   test "feed is_root?" do
     assert feeds(:service).is_root?
     assert !feeds(:boring_announcements).is_root?
   end
-
+
+  # A feed cannot be it's own parent
+  test "that a feed cannot be it's own parent" do
+    feed = feeds(:boring_announcements)
+    feed.update_attribute(:parent_id, feed.id)
+    assert feed.invalid?
+    assert feed.errors[:parent_id].any?
+  end
+
   # The ancestor tree is built and in order
   test "feed ancestors" do
     assert feeds(:service).ancestors.empty?
-    
+
     assert feeds(:announcements).ancestors.empty?
-    
+
     assert_equal feeds(:boring_announcements).ancestors, [feeds(:announcements)]
     assert_equal feeds(:sleepy_announcements).ancestors, [feeds(:boring_announcements), feeds(:announcements)]
   end
-  
+
   # Descendants are built and in order
   test "feed descendants" do
     assert feeds(:service).descendants.empty?
-    
+
     assert_equal feeds(:announcements).descendants.size, 3
     assert feeds(:announcements).descendants.include?(feeds(:boring_announcements))
     assert feeds(:announcements).descendants.include?(feeds(:sleepy_announcements))
     assert feeds(:announcements).descendants.include?(feeds(:important_announcements))
-    
+
     feed_list = [feeds(:boring_announcements), feeds(:sleepy_announcements), feeds(:important_announcements)]
     assert_equal feeds(:announcements).descendants, feed_list
-    
+
     assert_equal feeds(:boring_announcements).descendants, [feeds(:sleepy_announcements)]
   end
-  
+
   # Test feed depth
   test "feed depth" do
     assert_equal feeds(:service).depth, 0
     assert_equal feeds(:announcements).depth, 0
-    
+
     assert_equal feeds(:sleepy_announcements).depth, 2
   end
-  
+
   # Self and siblings works for children and roots
   test "self and siblings" do
     roots = Feed.roots
@@ -98,11 +106,11 @@ def setup
         assert root.self_and_siblings.include?(sibling)
       end
     end
-    
+
     assert_equal feeds(:boring_announcements).self_and_siblings.size, 2
     assert feeds(:boring_announcements).self_and_siblings.include?(feeds(:boring_announcements))
     assert feeds(:boring_announcements).self_and_siblings.include?(feeds(:important_announcements))
-    
+
     assert_equal feeds(:sleepy_announcements).self_and_siblings.size, 1
     assert feeds(:sleepy_announcements).self_and_siblings.include?(feeds(:sleepy_announcements))
   end