From 28fbb62ec4ae5a2967c25a5f7c6f138241d03d59 Mon Sep 17 00:00:00 2001
From: Adrian Mugnolo and Santiago Pastorino <adrian+santiago@wyeworks.com>
Date: Tue, 17 Dec 2013 13:14:34 -0200
Subject: [PATCH] Avoid unneeded logic

---
 lib/active_model/array_serializer.rb | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/active_model/array_serializer.rb b/lib/active_model/array_serializer.rb
index 5ab4cdb2..1fce09e3 100644
--- a/lib/active_model/array_serializer.rb
+++ b/lib/active_model/array_serializer.rb
@@ -45,8 +45,11 @@ module ActiveModel
     def embedded_in_root_associations
       @object.each_with_object({}) do |item, hash|
         serializer_for(item).embedded_in_root_associations.each_pair do |type, objects|
-          hash[type] = hash.fetch(type, []).concat(objects)
-          hash[type].uniq!
+          if hash.has_key?(type)
+            hash[type].concat(objects).uniq!
+          else
+            hash[type] = objects
+          end
         end
       end
     end