move Rails 4.2 counter cached associations destroy inside callbacks

This will allow to detect counter cached columns changes in callbacks
like `after_destroy` or `after_commit on: :destroy`.

lib/paranoia.rb

@@ -66,12 +66,8 @@ module Paranoia
   def destroy
   def destroy
     transaction do
     transaction do
       run_callbacks(:destroy) do
       run_callbacks(:destroy) do
-        touch_paranoia_column
-      end
-    end
-
-    if callbacks_result
-      if ActiveRecord::VERSION::STRING >= '4.2'
+        result = touch_paranoia_column
+        if result && ActiveRecord::VERSION::STRING >= '4.2'
           each_counter_cached_associations do |association|
           each_counter_cached_associations do |association|
             foreign_key = association.reflection.foreign_key.to_sym
             foreign_key = association.reflection.foreign_key.to_sym
             unless destroyed_by_association && destroyed_by_association.foreign_key.to_sym == foreign_key
             unless destroyed_by_association && destroyed_by_association.foreign_key.to_sym == foreign_key
@@ -81,9 +77,8 @@ module Paranoia
             end
             end
           end
           end
         end
         end
-      self
-    else
-      false
+        result
+      end
     end
     end
   end
   end
 
 

test/paranoia_test.rb

@@ -776,6 +776,19 @@ class ParanoiaTest < test_framework
     # assert_equal 0, parent_model_with_counter_cache_column.reload.related_models_count
     # assert_equal 0, parent_model_with_counter_cache_column.reload.related_models_count
   end
   end
 
 
+  def test_callbacks_for_counter_cache_column_update_on_destroy
+    parent_model_with_counter_cache_column = ParentModelWithCounterCacheColumn.create
+    related_model = parent_model_with_counter_cache_column.related_models.create
+
+    assert_equal nil, related_model.instance_variable_get(:@after_destroy_callback_called)
+    assert_equal nil, related_model.instance_variable_get(:@after_commit_on_destroy_callback_called)
+
+    related_model.destroy
+
+    assert related_model.instance_variable_get(:@after_destroy_callback_called)
+    assert related_model.instance_variable_get(:@after_commit_on_destroy_callback_called)
+  end
+
   # TODO: find a fix for Rails 4.1
   # TODO: find a fix for Rails 4.1
   if ActiveRecord::VERSION::STRING !~ /\A4\.1/
   if ActiveRecord::VERSION::STRING !~ /\A4\.1/
     def test_counter_cache_column_update_on_really_destroy
     def test_counter_cache_column_update_on_really_destroy
@@ -788,6 +801,22 @@ class ParanoiaTest < test_framework
     end
     end
   end
   end
 
 
+  # TODO: find a fix for Rails 4.0 and 4.1
+  if ActiveRecord::VERSION::STRING >= '4.2'
+    def test_callbacks_for_counter_cache_column_update_on_really_destroy!
+      parent_model_with_counter_cache_column = ParentModelWithCounterCacheColumn.create
+      related_model = parent_model_with_counter_cache_column.related_models.create
+
+      assert_equal nil, related_model.instance_variable_get(:@after_destroy_callback_called)
+      assert_equal nil, related_model.instance_variable_get(:@after_commit_on_destroy_callback_called)
+
+      related_model.really_destroy!
+
+      assert related_model.instance_variable_get(:@after_destroy_callback_called)
+      assert related_model.instance_variable_get(:@after_commit_on_destroy_callback_called)
+    end
+  end
+
   private
   private
   def get_featureful_model
   def get_featureful_model
     FeaturefulModel.new(:name => "not empty")
     FeaturefulModel.new(:name => "not empty")
@@ -852,6 +881,19 @@ class RelatedModel < ActiveRecord::Base
   acts_as_paranoid
   acts_as_paranoid
   belongs_to :parent_model
   belongs_to :parent_model
   belongs_to :parent_model_with_counter_cache_column, counter_cache: true
   belongs_to :parent_model_with_counter_cache_column, counter_cache: true
+
+  after_destroy do |model|
+    if parent_model_with_counter_cache_column && parent_model_with_counter_cache_column.reload.related_models_count == 0
+      model.instance_variable_set :@after_destroy_callback_called, true
+    end
+  end
+  after_commit :set_after_commit_on_destroy_callback_called, on: :destroy
+
+  def set_after_commit_on_destroy_callback_called
+    if parent_model_with_counter_cache_column && parent_model_with_counter_cache_column.reload.related_models_count == 0
+      self.instance_variable_set :@after_commit_on_destroy_callback_called, true
+    end
+  end
 end
 end
 
 
 class Employer < ActiveRecord::Base
 class Employer < ActiveRecord::Base