serialize_ids call methods on the corresponding serializer if defined

test/serializer_test.rb

@@ -454,6 +454,39 @@ class SerializerTest < ActiveModel::TestCase
     }, json)
   end
 
+  def test_methods_take_priority_over_associations_and_call_the_appropriate_id_method
+    comment_serializer = Class.new(ActiveModel::Serializer) do
+      def id
+        "OMG"
+      end
+    end
+
+    post_serializer = Class.new(ActiveModel::Serializer) do
+      attributes :title
+      has_many :comments, :serializer => comment_serializer
+      embed :ids
+
+      def comments
+        object.comments[0,1]
+      end
+    end
+
+    post = Post.new(:title => "My Post")
+    comments = [Comment.new(:title => "Comment1", :id => 1), Comment.new(:title => "Comment2", :id => 2)]
+    post.comments = comments
+
+    post.class_eval do
+      define_method :comment_ids, lambda {
+        self.comments.map { |c| c.read_attribute_for_serialization(:id) }
+      }
+    end
+    json = post_serializer.new(post).as_json
+    assert_equal({
+      :title => "My Post",
+      :comment_ids => ["OMG"]
+    }, json)
+  end
+
   def test_embed_objects
     serializer = post_serializer
 
@@ -684,6 +717,42 @@ class SerializerTest < ActiveModel::TestCase
     }, hash.as_json)
   end
 
+  def test_embed_id_for_has_one_overriding_associated_id
+    author_serializer = Class.new(ActiveModel::Serializer) do
+      def id
+        "OMG"
+      end
+    end
+
+    serializer_class = Class.new(ActiveModel::Serializer) do
+      embed :ids
+      root :post
+
+      attributes :title, :body
+      has_one :author, :serializer => author_serializer
+    end
+
+    post_class = Class.new(Model) do
+      attr_accessor :author
+    end
+
+    author_class = Class.new(Model)
+
+    post = post_class.new(:title => "New Post", :body => "It's a new post!")
+    author = author_class.new(:id => 5)
+    post.author = author
+
+    hash = serializer_class.new(post)
+
+    assert_equal({
+      :post => {
+        :title => "New Post",
+        :body => "It's a new post!",
+        :author_id => "OMG"
+      }
+    }, hash.as_json)
+  end
+
   def test_embed_objects_for_has_one
     author_serializer = Class.new(ActiveModel::Serializer) do
       attributes :id, :name