Added an unfollowed class method

acts_as_follower.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |s|
   s.require_paths = ["lib"]
 
   s.add_development_dependency "sqlite3"
-  s.add_development_dependency "shoulda"
-  s.add_development_dependency "factory_girl"
+  s.add_development_dependency "shoulda", "2.11.3"
+  s.add_development_dependency "factory_girl", "2.0.5"
   s.add_development_dependency "rails", "~>3.0.10"
 end

lib/acts_as_follower/followable.rb

@@ -10,6 +10,13 @@ def acts_as_followable
         has_many :followings, :as => :followable, :dependent => :destroy, :class_name => 'Follow'
         include ActsAsFollower::Followable::InstanceMethods
         include ActsAsFollower::FollowerLib
+        extend ActsAsFollower::Followable::SingletonMethods
+      end
+    end
+
+    module SingletonMethods
+      def unfollowed
+        self.where("NOT EXISTS (SELECT 1 FROM follows WHERE followable_id = #{self.table_name}.id AND followable_type = '#{self.model_name}')")
       end
     end
 
@@ -25,8 +32,8 @@ def followers_by_type(follower_type, options={})
         follows = follower_type.constantize.
           joins(:follows).
           where('follows.blocked'         => false,
-                'follows.followable_id'   => self.id, 
-                'follows.followable_type' => parent_class_name(self), 
+                'follows.followable_id'   => self.id,
+                'follows.followable_type' => parent_class_name(self),
                 'follows.follower_type'   => follower_type)
         if options.has_key?(:limit)
           follows = follows.limit(options[:limit])

test/acts_as_followable_test.rb

@@ -2,6 +2,21 @@
 
 class ActsAsFollowableTest < ActiveSupport::TestCase
 
+  context "class methods" do
+    context "unfollowed" do
+      setup do
+        @sam = Factory(:sam)
+        @oasis = Factory(:oasis)
+        @metallica = Factory(:metallica)
+        @sam.follow(@oasis)
+      end
+
+      should "return unfollowed bands" do
+        assert_equal 1, Band.unfollowed.count
+      end
+    end
+  end
+
   context "instance methods" do
     setup do
       @sam = Factory(:sam)