Fix user_badges n+1 query.

app/controllers/user_badges_controller.rb

@@ -6,8 +6,9 @@ class UserBadgesController < ApplicationController
       user_badges = user.user_badges
     else
       badge = fetch_badge_from_params
-      user_badges = badge.user_badges.order('granted_at DESC').limit(200).to_a
+      user_badges = badge.user_badges.order('granted_at DESC').limit(200)
     end
+    user_badges = user_badges.includes(:user, :granted_by, badge: :badge_type)
     render_serialized(user_badges, UserBadgeSerializer, root: "user_badges")
   end
 

app/models/user.rb

@@ -497,7 +497,7 @@ class User < ActiveRecord::Base
   end
 
   def featured_user_badges
-    user_badges.joins(:badge).order('badges.badge_type_id ASC, badges.grant_count ASC').includes(:granted_by, badge: :badge_type).limit(3)
+    user_badges.joins(:badge).order('badges.badge_type_id ASC, badges.grant_count ASC').includes(:user, :granted_by, badge: :badge_type).limit(3)
   end
 
   def self.count_by_signup_date(sinceDaysAgo=30)

app/serializers/user_badge_serializer.rb

@@ -1,7 +1,7 @@
 class UserBadgeSerializer < ApplicationSerializer
   attributes :id, :granted_at
 
-  has_one :user
   has_one :badge
+  has_one :user, serializer: BasicUserSerializer, root: :users
   has_one :granted_by, serializer: BasicUserSerializer, root: :users
 end