Replaced valid? in before_save callback with simpler sanity check

Minor refactors

Gemfile

@@ -2,6 +2,10 @@ source 'http://rubygems.org'
 
 gemspec
 
+group :development, :test do
+  gem 'debugger' if RUBY_VERSION =~ /\A1.9/
+end
+
 group :development do
   gem 'rdoc'
 end

lib/ancestry.rb

@@ -2,3 +2,7 @@
 require File.join(File.expand_path(File.dirname(__FILE__)), 'ancestry/instance_methods')
 require File.join(File.expand_path(File.dirname(__FILE__)), 'ancestry/exceptions')
 require File.join(File.expand_path(File.dirname(__FILE__)), 'ancestry/has_ancestry')
+
+module Ancestry
+  ANCESTRY_PATTERN = /\A[0-9]+(\/[0-9]+)*\Z/
+end

lib/ancestry/has_ancestry.rb

@@ -27,7 +27,7 @@ def has_ancestry options = {}
     self.base_class = self
 
     # Validate format of ancestry column value
-    validates_format_of ancestry_column, :with => /\A[0-9]+(\/[0-9]+)*\Z/, :allow_nil => true
+    validates_format_of ancestry_column, :with => Ancestry::ANCESTRY_PATTERN, :allow_nil => true
 
     # Validate that the ancestor ids don't include own id
     validate :ancestry_exclude_self

lib/ancestry/instance_methods.rb

@@ -9,8 +9,8 @@ def ancestry_exclude_self
     def update_descendants_with_new_ancestry
       # Skip this if callbacks are disabled
       unless ancestry_callbacks_disabled?
-        # If node is valid, not a new record and ancestry was updated ...
-        if changed.include?(self.base_class.ancestry_column.to_s) && !new_record? && valid?
+        # If node is not a new record and ancestry was updated and the new ancestry is sane ...
+        if changed.include?(self.base_class.ancestry_column.to_s) && !new_record? && sane_ancestry?
           # ... for each descendant ...
           unscoped_descendants.each do |descendant|
             # ... replace old ancestry with new ancestry
@@ -221,9 +221,15 @@ def primary_key_type
     end
 
     def unscoped_descendants
-      self.base_class.send(:with_exclusive_scope) do 
+      self.base_class.unscoped do 
         self.base_class.all(:conditions => descendant_conditions) 
       end
     end
+
+    # basically validates the ancestry, but also applied if validation is
+    # bypassed to determine if chidren should be affected
+    def sane_ancestry?
+      ancestry.nil? || (ancestry.to_s =~ Ancestry::ANCESTRY_PATTERN && !ancestor_ids.include?(self.id))
+    end
   end
 end

test/environment.rb

@@ -9,7 +9,11 @@
 require 'active_record'
 require 'active_support/test_case'
 require 'test/unit'
-require 'ancestry'
+
+# this is to make absolutely sure we test this one, not the one
+# installed on the system.
+require File.expand_path('../../lib/ancestry', __FILE__)
+
 require 'debugger' if RUBY_VERSION =~ /\A1.9/
 
 class AncestryTestDatabase