scopes can take an object that responds to call

activerecord/lib/active_record/named_scope.rb

@@ -104,7 +104,7 @@ module ActiveRecord
         extension = Module.new(&Proc.new) if block_given?
 
         scopes[name] = lambda do |*args|
-          options = scope_options.is_a?(Proc) ? scope_options.call(*args) : scope_options
+          options = scope_options.respond_to?(:call) ? scope_options.call(*args) : scope_options
 
           relation = if options.is_a?(Hash)
             scoped.apply_finder_options(options)

activerecord/test/cases/named_scope_test.rb

@@ -125,6 +125,12 @@ class NamedScopeTest < ActiveRecord::TestCase
     assert_equal posts_with_authors_at_address_titles, Post.with_authors_at_address(address).find(:all, :select => 'title')
   end
 
+  def test_scope_with_object
+    objects = Topic.with_object
+    assert_operator objects.length, :>, 0
+    assert objects.all?(&:approved?), 'all objects should be approved'
+  end
+
   def test_extensions
     assert_equal 1, Topic.anonymous_extension.one
     assert_equal 2, Topic.named_extension.two

activerecord/test/models/topic.rb

@@ -18,6 +18,13 @@ class Topic < ActiveRecord::Base
       1
     end
   end
+
+  scope :with_object, Class.new(Struct.new(:klass)) {
+    def call
+      klass.where(:approved => true)
+    end
+  }.new(self)
+
   module NamedExtension
     def two
       2