Fix compatible issues with trashable and counter_cache

app/models/comment.rb

@@ -11,21 +11,7 @@ class Comment < ActiveRecord::Base
   validates :commentable, :user, presence: true
   validates :body, presence: true
 
-  after_trash :decrement_counter_cache, :delete_all_notifications
-  after_restore :increment_counter_cache
-  after_destroy :increment_counter_cache, if: :trashed?
-
-  def increment_counter_cache
-    if commentable.has_attribute? :comments_count
-      commentable.class.update_counters commentable.id, comments_count: 1
-    end
-  end
-
-  def decrement_counter_cache
-    if commentable.has_attribute? :comments_count
-      commentable.class.update_counters commentable.id, comments_count: -1
-    end
-  end
+  after_trash :delete_all_notifications
 
   def delete_all_notifications
     notifications.delete_all

app/models/concerns/trashable.rb

@@ -7,6 +7,47 @@ module Trashable
     scope :with_trashed, -> { unscope(where: :trashed) }
 
     define_model_callbacks :trash, :restore
+
+    class << self
+      alias_method_chain :belongs_to, :trashable
+    end
+  end
+
+  module ClassMethods
+    def belongs_to_with_trashable(name, scope = nil, options = {})
+      belongs_to_without_trashable(name, scope, options)
+
+      reflection = reflections[name]
+
+      if reflection.options[:counter_cache]
+        after_restore lambda { |record|
+          record.belongs_to_counter_cache_after_create(reflection)
+        }
+
+        before_trash lambda { |record|
+          record.belongs_to_counter_cache_before_destroy(reflection)
+        }
+      end
+
+      return if method_defined? :belongs_to_counter_cache_before_destroy_with_trashable
+
+      class_eval do
+        def belongs_to_counter_cache_before_destroy_with_trashable(reflection)
+          unless trashed?
+            belongs_to_counter_cache_before_destroy_without_trashable(reflection)
+          end
+        end
+
+        def belongs_to_counter_cache_after_update_with_trashable(reflection)
+          unless trashed?
+            belongs_to_counter_cache_after_update_without_trashable(reflection)
+          end
+        end
+      end
+
+      alias_method_chain :belongs_to_counter_cache_before_destroy, :trashable
+      alias_method_chain :belongs_to_counter_cache_after_update, :trashable
+    end
   end
 
   def trash

app/models/topic.rb

@@ -14,23 +14,6 @@ class Topic < ActiveRecord::Base
   after_create :update_hot, :owner_subscribe
   after_touch :update_hot
 
-  after_trash :decrement_counter_cache
-  after_restore :increment_counter_cache
-  # Fix double desc counter
-  after_destroy :increment_counter_cache, if: :trashed?
-
-  def increment_counter_cache
-    if category
-      Category.update_counters category.id, topics_count: 1
-    end
-  end
-
-  def decrement_counter_cache
-    if category
-      Category.update_counters category.id, topics_count: -1
-    end
-  end
-
   def calculate_hot
     order = Math.log10([comments_count, 1].max)
     order + created_at.to_f / 45000