Ensure NamedScope#any? uses COUNT query wherever possible. [#680 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

activerecord/lib/active_record/named_scope.rb

@@ -103,7 +103,7 @@ module ActiveRecord
       attr_reader :proxy_scope, :proxy_options
 
       [].methods.each do |m|
-        unless m =~ /(^__|^nil\?|^send|^object_id$|class|extend|find|count|sum|average|maximum|minimum|paginate|first|last|empty?)/
+        unless m =~ /(^__|^nil\?|^send|^object_id$|class|extend|find|count|sum|average|maximum|minimum|paginate|first|last|empty?|any?)/
           delegate m, :to => :proxy_found
         end
       end
@@ -140,6 +140,14 @@ module ActiveRecord
         @found ? @found.empty? : count.zero?
       end
 
+      def any?
+        if block_given?
+          proxy_found.any? { |*block_args| yield(*block_args) }
+        else
+          !empty?
+        end
+      end
+
       protected
       def proxy_found
         @found || load_found

activerecord/test/cases/named_scope_test.rb

@@ -184,6 +184,28 @@ class NamedScopeTest < ActiveRecord::TestCase
     end
   end
 
+  def test_any_should_not_load_results
+    topics = Topic.base
+    assert_queries(1) do
+      topics.expects(:empty?).returns(true)
+      assert !topics.any?
+    end
+  end
+
+  def test_any_should_call_proxy_found_if_using_a_block
+    topics = Topic.base
+    assert_queries(1) do
+      topics.expects(:empty?).never
+      topics.any? { true }
+    end
+  end
+
+  def test_any_should_not_fire_query_if_named_scope_loaded
+    topics = Topic.base
+    topics.collect # force load
+    assert_no_queries { assert topics.any? }
+  end
+
   def test_should_build_with_proxy_options
     topic = Topic.approved.build({})
     assert topic.approved