Add constant time PropertyCollection#count

lib/smart_properties/property_collection.rb

@@ -1,6 +1,9 @@
+require 'forwardable'
+
 module SmartProperties
   class PropertyCollection
     include Enumerable
+    extend Forwardable
 
     attr_reader :parent
 
@@ -45,17 +48,17 @@ def keys
       collection_with_parent_collection.keys.map(&:to_sym)
     end
 
-    def values
-      collection_with_parent_collection.values
-    end
-
     def each(&block)
       return to_enum(:each) if block.nil?
       collection_with_parent_collection.each { |name, value| block.call([name.to_sym, value]) }
     end
 
+    def to_h
+      each.to_h
+    end
+
     def to_hash
-      Hash[each.to_a]
+      to_h
     end
 
     def register(child)
@@ -64,6 +67,8 @@ def register(child)
       nil
     end
 
+    def_delegators :collection_with_parent_collection, :count, :size, :length, :values
+
     protected
 
     attr_accessor :children

spec/property_collection_caching_spec.rb → spec/property_collection_spec.rb

@@ -36,4 +36,14 @@
       expect(base_class.new).to have_smart_property(:title)
     end.not_to raise_error(SystemStackError)
   end
+
+  specify "PropertyCollection has O(1) #count" do
+    property_collection = Class.new(SmartProperties::PropertyCollection) do
+      def collection_with_parent_collection
+        mock('collection').expects(:count).once.returns(42)
+      end
+    end
+
+    expect(property_collection.new.count).to eq(42)
+  end
 end