1 files changed, 21 insertions, 57 deletions

diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index 2a97d0ed31..a9f6aaafef 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -6,6 +6,7 @@ module ActiveRecord
     # If the association has a <tt>:through</tt> option further specialization
     # is provided by its child HasManyThroughAssociation.
     class HasManyAssociation < CollectionAssociation #:nodoc:
+      include ForeignAssociation
 
       def handle_dependency
         case options[:dependent]
@@ -14,9 +15,16 @@ module ActiveRecord
 
         when :restrict_with_error
           unless empty?
-            record = klass.human_attribute_name(reflection.name).downcase
-            owner.errors.add(:base, :"restrict_dependent_destroy.many", record: record)
-            false
+            record = owner.class.human_attribute_name(reflection.name).downcase
+            message = owner.errors.generate_message(:base, :'restrict_dependent_destroy.many', record: record, raise: true) rescue nil
+            if message
+              ActiveSupport::Deprecation.warn(<<-MESSAGE.squish)
+                The error key `:'restrict_dependent_destroy.many'` has been deprecated and will be removed in Rails 5.1.
+                Please use `:'restrict_dependent_destroy.has_many'` instead.
+              MESSAGE
+            end
+            owner.errors.add(:base, message || :'restrict_dependent_destroy.has_many', record: record)
+            throw(:abort)
           end
 
         else
@@ -42,7 +50,7 @@ module ActiveRecord
       end
 
       def empty?
-        if has_cached_counter?
+        if reflection.has_cached_counter?
           size.zero?
         else
           super
@@ -65,8 +73,8 @@ module ActiveRecord
         # If the collection is empty the target is set to an empty array and
         # the loaded flag is set to true as well.
         def count_records
-          count = if has_cached_counter?
-            owner.read_attribute cached_counter_attribute_name
+          count = if reflection.has_cached_counter?
+            owner._read_attribute reflection.counter_cache_column
           else
             scope.count
           end
@@ -79,56 +87,20 @@ module ActiveRecord
           [association_scope.limit_value, count].compact.min
         end
 
-        def has_cached_counter?(reflection = reflection())
-          owner.attribute_present?(cached_counter_attribute_name(reflection))
-        end
-
-        def cached_counter_attribute_name(reflection = reflection())
-          options[:counter_cache] || "#{reflection.name}_count"
-        end
-
         def update_counter(difference, reflection = reflection())
-          update_counter_in_database(difference, reflection)
-          update_counter_in_memory(difference, reflection)
-        end
-
-        def update_counter_in_database(difference, reflection = reflection())
-          if has_cached_counter?(reflection)
-            counter = cached_counter_attribute_name(reflection)
-            owner.class.update_counters(owner.id, counter => difference)
+          if reflection.has_cached_counter?
+            owner.increment!(reflection.counter_cache_column, difference)
           end
         end
 
         def update_counter_in_memory(difference, reflection = reflection())
-          if has_cached_counter?(reflection)
-            counter = cached_counter_attribute_name(reflection)
-            owner[counter] += difference
-            owner.changed_attributes.delete(counter) # eww
+          if reflection.counter_must_be_updated_by_has_many?
+            counter = reflection.counter_cache_column
+            owner.increment(counter, difference)
+            owner.send(:clear_attribute_change, counter) # eww
           end
         end
 
-        # This shit is nasty. We need to avoid the following situation:
-        #
-        #   * An associated record is deleted via record.destroy
-        #   * Hence the callbacks run, and they find a belongs_to on the record with a
-        #     :counter_cache options which points back at our owner. So they update the
-        #     counter cache.
-        #   * In which case, we must make sure to *not* update the counter cache, or else
-        #     it will be decremented twice.
-        #
-        # Hence this method.
-        def inverse_updates_counter_cache?(reflection = reflection())
-          counter_name = cached_counter_attribute_name(reflection)
-          inverse_updates_counter_named?(counter_name, reflection)
-        end
-
-        def inverse_updates_counter_named?(counter_name, reflection = reflection())
-          reflection.klass._reflections.values.any? { |inverse_reflection|
-            :belongs_to == inverse_reflection.macro &&
-            inverse_reflection.counter_cache_column == counter_name
-          }
-        end
-
         def delete_count(method, scope)
           if method == :delete_all
             scope.delete_all
@@ -146,21 +118,13 @@ module ActiveRecord
         def delete_records(records, method)
           if method == :destroy
             records.each(&:destroy!)
-            update_counter(-records.length) unless inverse_updates_counter_cache?
+            update_counter(-records.length) unless reflection.inverse_updates_counter_cache?
           else
             scope = self.scope.where(reflection.klass.primary_key => records)
             update_counter(-delete_count(method, scope))
           end
         end
 
-        def foreign_key_present?
-          if reflection.klass.primary_key
-            owner.attribute_present?(reflection.association_primary_key)
-          else
-            false
-          end
-        end
-
         def concat_records(records, *)
           update_counter_if_success(super, records.length)
         end