Prevent double firing the before save callback of new object when the parent association saved in the callback

Related #18155, #26661, 268a5bb, #27434, #27442, and #28599.

Originally #18155 was introduced for preventing double insertion caused
by the after save callback. But it was caused the before save issue
(#26661). 268a5bb fixed #26661, but it was caused the performance
regression (#27434). #27442 added new record to `target` before calling
callbacks for fixing #27434. But it was caused double firing before save
callback (#28599). We cannot add new object to `target` before saving
the object.

This is improving #18155 to only track callbacks after `save`.

Fixes #28599.

1 files changed, 32 insertions, 35 deletions

diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 77282e6463..62c944fce3 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -280,35 +280,6 @@ module ActiveRecord
         replace_on_target(record, index, skip_callbacks, &block)
       end
 
-      def replace_on_target(record, index, skip_callbacks)
-        callback(:before_add, record) unless skip_callbacks
-
-        begin
-          if index
-            record_was = target[index]
-            target[index] = record
-          else
-            target << record
-          end
-
-          set_inverse_instance(record)
-
-          yield(record) if block_given?
-        rescue
-          if index
-            target[index] = record_was
-          else
-            target.delete(record)
-          end
-
-          raise
-        end
-
-        callback(:after_add, record) unless skip_callbacks
-
-        record
-      end
-
       def scope
         scope = super
         scope.none! if null_scope?
@@ -385,15 +356,19 @@ module ActiveRecord
             transaction do
               add_to_target(build_record(attributes)) do |record|
                 yield(record) if block_given?
-                insert_record(record, true, raise)
+                insert_record(record, true, raise) { @_was_loaded = loaded? }
               end
             end
           end
         end
 
         # Do the relevant stuff to insert the given record into the association collection.
-        def insert_record(record, validate = true, raise = false)
-          raise NotImplementedError
+        def insert_record(record, validate = true, raise = false, &block)
+          if raise
+            record.save!(validate: validate, &block)
+          else
+            record.save(validate: validate, &block)
+          end
         end
 
         def create_scope
@@ -448,19 +423,41 @@ module ActiveRecord
           end
         end
 
-        def concat_records(records, should_raise = false)
+        def concat_records(records, raise = false)
           result = true
 
           records.each do |record|
             raise_on_type_mismatch!(record)
-            add_to_target(record) do |rec|
-              result &&= insert_record(rec, true, should_raise) unless owner.new_record?
+            add_to_target(record) do
+              result &&= insert_record(record, true, raise) { @_was_loaded = loaded? } unless owner.new_record?
             end
           end
 
           result && records
         end
 
+        def replace_on_target(record, index, skip_callbacks)
+          callback(:before_add, record) unless skip_callbacks
+
+          set_inverse_instance(record)
+
+          @_was_loaded = true
+
+          yield(record) if block_given?
+
+          if index
+            target[index] = record
+          elsif @_was_loaded || !loaded?
+            target << record
+          end
+
+          callback(:after_add, record) unless skip_callbacks
+
+          record
+        ensure
+          @_was_loaded = nil
+        end
+
         def callback(method, record)
           callbacks_for(method).each do |callback|
             callback.call(method, owner, record)