Many relations need to implement #scoped. Fixes #1028.

lib/mongoid/relations/many.rb

@@ -83,6 +83,18 @@ def respond_to?(name, include_private = false)
         [].respond_to?(name, include_private) || super
       end
 
+      # This is public access to the relation's criteria.
+      #
+      # @example Get the scoped relation.
+      #   relation.scoped
+      #
+      # @return [ Criteria ] The scoped criteria.
+      #
+      # @since 2.1.0
+      def scoped
+        criteria
+      end
+
       # Gets the document as a serializable hash, used by ActiveModel's JSON and
       # XML serializers. This override is just to be able to pass the :include
       # and :except options to get associations in the hash.

spec/functional/mongoid/relations/embedded/many_spec.rb

@@ -1673,6 +1673,25 @@
     end
   end
 
+  describe "#scoped" do
+
+    let(:person) do
+      Person.new
+    end
+
+    let(:scoped) do
+      person.addresses.scoped
+    end
+
+    it "returns the relation criteria" do
+      scoped.should be_a(Mongoid::Criteria)
+    end
+
+    it "returns with an empty selector" do
+      scoped.selector.should be_empty
+    end
+  end
+
   [ :size, :length ].each do |method|
 
     describe "##{method}" do

spec/functional/mongoid/relations/referenced/many_spec.rb

@@ -2158,6 +2158,25 @@
     end
   end
 
+  describe "#scoped" do
+
+    let(:person) do
+      Person.new
+    end
+
+    let(:scoped) do
+      person.posts.scoped
+    end
+
+    it "returns the relation criteria" do
+      scoped.should be_a(Mongoid::Criteria)
+    end
+
+    it "returns with an empty selector" do
+      scoped.selector.should eq({ "person_id" => person.id })
+    end
+  end
+
   [ :size, :length ].each do |method|
 
     describe "##{method}" do

spec/functional/mongoid/relations/referenced/many_to_many_spec.rb

@@ -1736,6 +1736,25 @@
     end
   end
 
+  describe "#scoped" do
+
+    let(:person) do
+      Person.new
+    end
+
+    let(:scoped) do
+      person.preferences.scoped
+    end
+
+    it "returns the relation criteria" do
+      scoped.should be_a(Mongoid::Criteria)
+    end
+
+    it "returns with an empty selector" do
+      scoped.selector.should eq({ :_id => { "$in" => [] }})
+    end
+  end
+
   [ :size, :length ].each do |method|
 
     describe "##{method}" do