Passes serializer options down into associations

lib/active_model/serializer.rb

@@ -176,19 +176,20 @@ def attributes(options = {})
     end
 
     def each_association(&block)
-      self.class._associations.dup.each do |name, options|
+      self.class._associations.dup.each do |name, association_options|
         next unless object
 
         association = object.send(name)
         association_value = send(name)
-        serializer_class = ActiveModel::Serializer.serializer_for(association, options)
+        serializer_class = ActiveModel::Serializer.serializer_for(association, association_options)
+
         serializer = serializer_class.new(
           association_value,
-          serializer_from_options(options)
+          serializer_from_options(association_options).merge(options)
         ) if serializer_class
 
         if block_given?
-          block.call(name, serializer, options[:association_options])
+          block.call(name, serializer, association_options[:association_options])
         end
       end
     end

test/fixtures/poro.rb

@@ -99,6 +99,10 @@ def self.root_name
 
   belongs_to :post
   belongs_to :author
+
+  def custom_options
+    options
+  end
 end
 
 AuthorSerializer = Class.new(ActiveModel::Serializer) do

test/serializers/associations_test.rb

@@ -37,7 +37,7 @@ def setup
         @post.author = @author
         @author.posts = [@post]
 
-        @post_serializer = PostSerializer.new(@post)
+        @post_serializer = PostSerializer.new(@post, {custom_options: true})
         @author_serializer = AuthorSerializer.new(@author)
         @comment_serializer = CommentSerializer.new(@comment)
       end
@@ -65,6 +65,14 @@ def test_has_many_and_has_one
         end
       end
 
+      def test_serializer_options_are_passed_into_associations_serializers
+        @post_serializer.each_association do |name, association|
+          if name == :comments
+            assert association.first.custom_options[:custom_options]
+          end
+        end
+      end
+
       def test_belongs_to
         assert_equal(
           { post: { type: :belongs_to, association_options: {} },