Added counter optimization for AssociationCollection#any? so...

Added counter optimization for AssociationCollection#any? so person.friends.any? won't actually load the full association if we have the count in a cheaper form [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5676 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Added counter optimization for AssociationCollection#any? so person.friends.any? won't actually load the full association if we have the count in a cheaper form [DHH]
+
 * Subclasses of an abstract class work with single-table inheritance.  #5704 [nick+rails@ag.arizona.edu, Ryan Davis, Jeremy Kemper]
 
 * Change fixture_path to a class inheritable accessor allowing test cases to have their own custom set of fixtures. #6672 [zdennis]

activerecord/lib/active_record/associations/association_collection.rb

@@ -119,6 +119,10 @@ def length
       def empty?
         size.zero?
       end
+      
+      def any?
+        !empty?
+      end
 
       def uniq(collection = self)
         seen = Set.new

activerecord/test/associations_test.rb

@@ -508,7 +508,9 @@ def test_finding_using_sql
 
   def test_counting_using_sql
     assert_equal 1, Firm.find(:first).clients_using_counter_sql.size
+    assert Firm.find(:first).clients_using_counter_sql.any?
     assert_equal 0, Firm.find(:first).clients_using_zero_counter_sql.size
+    assert !Firm.find(:first).clients_using_zero_counter_sql.any?
   end
 
   def test_counting_non_existant_items_using_sql