allow subclasses of ActiveModel::Serializer to override reflections

Author: markus

lib/active_model/serializer/associations.rb

@@ -97,11 +97,15 @@ def associations
         return unless object
 
         Enumerator.new do |y|
-          self.class._reflections.each do |reflection|
+          reflections.each do |reflection|
             y.yield reflection.build_association(self, options)
           end
         end
       end
+
+      def reflections
+        self.class._reflections
+      end
     end
   end
 end

test/fixtures/poro.rb

@@ -102,6 +102,13 @@ def custom_options
   end
 end
 
+CustomizablePostSerializer = Class.new(PostSerializer) do
+  def reflections
+    excludes = @options[:excludes] || []
+    super.select{ |r| excludes.exclude?(r.name) }
+  end
+end
+
 SpammyPostSerializer = Class.new(ActiveModel::Serializer) do
   attributes :id
   has_many :related

test/serializers/associations_test.rb

@@ -145,6 +145,14 @@ def test_associations_custom_keys
         assert expected_association_keys.include? :writer
         assert expected_association_keys.include? :site
       end
+
+      def test_overriding_associations
+        serializer = CustomizablePostSerializer.new(@post, excludes: [:comments])
+
+        association_keys = serializer.associations.map(&:key)
+
+        assert association_keys.exclude? :comments
+      end
     end
   end
 end