Collection can now delegate to the model method, with scope

* This allows a Collection to delegate to a model's method with the
  proper level of scope.  This should also allow chaining of model
  methods that return Collection objects, as well as using model
  methods that return a Resource with the correct scope.

lib/dm-core/collection.rb

@@ -477,12 +477,26 @@ def default_attributes
       default_attributes
     end
 
+    ##
+    # check to see if collection can respond to the method
+    #
+    # @param method [Symbol] method to check in the object
+    # @param include_private [FalseClass, TrueClass] if set to true,
+    #   collection will check private methods
+    #
+    # @return [TrueClass, FalseClass]
+    #   TrueClass indicates the method can be responded to by the collection
+    #   FalseClass indicates the method can not be responded to by the collection
+    #
+    # @api public
+    def respond_to?(method, include_private = false)
+      super || model.respond_to?(method, include_private) || relationships.has_key?(method)
+    end
+
     protected
 
     ##
     # @api private
-    #
-    # @api public
     def model
       query.model
     end
@@ -594,7 +608,11 @@ def set_relative_position(query)
     ##
     # @api private
     def method_missing(method, *args, &block)
-      if relationship = relationships[method]
+      if model.respond_to?(method)
+        model.send(:with_scope, query) do
+          model.send(method, *args, &block)
+        end
+      elsif relationship = relationships[method]
         klass = model == relationship.child_model ? relationship.parent_model : relationship.child_model
 
         # TODO: when self.query includes an offset/limit use it as a
@@ -610,10 +628,10 @@ def method_missing(method, *args, &block)
           :links  => self.query.links + [ relationship ]
         )
 
-        return klass.all(query, &block)
+        klass.all(query, &block)
+      else
+        super
       end
-
-      super
     end
   end # class Collection
 end # module DataMapper

spec/integration/collection_spec.rb

@@ -29,6 +29,10 @@ def self.default_repository_name
     property :zebra_id, Integer
 
     belongs_to :zebra
+
+    def self.sort_by_name
+      all(:order => [ :name ])
+    end
   end
 
   class CollectionSpecParty
@@ -71,46 +75,6 @@ def setup
     end
   end
 
-  describe 'association proxying' do
-    include CollectionSpecHelper
-
-    before do
-      setup
-    end
-
-    it "should provide a Query" do
-      repository(ADAPTER) do
-        zebras = Zebra.all(:order => [ :name ])
-        zebras.query.order.should == [DataMapper::Query::Direction.new(Zebra.properties(ADAPTER)[:name])]
-      end
-    end
-
-    it "should proxy the relationships of the model" do
-      repository(ADAPTER) do
-        zebras = Zebra.all
-        zebras.should have(3).entries
-        zebras.find { |zebra| zebra.name == 'Nancy' }.stripes.should have(2).entries
-        zebras.stripes.should == [@babe, @snowball]
-      end
-    end
-
-    it "should preserve it's order on reload" do
-      repository(ADAPTER) do |r|
-        zebras = Zebra.all(:order => [ :name ])
-
-        order = %w{ Bessie Nancy Steve }
-
-        zebras.map { |z| z.name }.should == order
-
-        # Force a lazy-load call:
-        zebras.first.notes
-
-        # The order should be unaffected.
-        zebras.map { |z| z.name }.should == order
-      end
-    end
-  end
-
   describe DataMapper::Collection do
     include CollectionSpecHelper
 
@@ -163,6 +127,49 @@ def setup
       results.first.should == bob
     end
 
+    describe 'model proxying' do
+      it 'should delegate to a model method' do
+        stripes = @model.first.stripes
+        stripes.should respond_to(:sort_by_name)
+        stripes.sort_by_name.should == [ @babe, @snowball ]
+      end
+    end
+
+    describe 'association proxying' do
+      it "should provide a Query" do
+        repository(ADAPTER) do
+          zebras = Zebra.all(:order => [ :name ])
+          zebras.query.order.should == [DataMapper::Query::Direction.new(Zebra.properties(ADAPTER)[:name])]
+        end
+      end
+
+      it "should proxy the relationships of the model" do
+        repository(ADAPTER) do
+          zebras = Zebra.all
+          zebras.should have(3).entries
+          zebras.find { |zebra| zebra.name == 'Nancy' }.stripes.should have(2).entries
+          zebras.should respond_to(:stripes)
+          zebras.stripes.should == [@babe, @snowball]
+        end
+      end
+
+      it "should preserve it's order on reload" do
+        repository(ADAPTER) do |r|
+          zebras = Zebra.all(:order => [ :name ])
+
+          order = %w{ Bessie Nancy Steve }
+
+          zebras.map { |z| z.name }.should == order
+
+          # Force a lazy-load call:
+          zebras.first.notes
+
+          # The order should be unaffected.
+          zebras.map { |z| z.name }.should == order
+        end
+      end
+    end
+
     describe '.new' do
       describe 'with non-index keys' do
         it 'should instantiate read-only resources' do