No need to define methods on descendants.

Addresses feedback from https://github.com/rails/rails/pull/31913#issuecomment-365983580

1 files changed, 18 insertions, 18 deletions

diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb
index cece3eb19f..de42a075e1 100644
--- a/activesupport/lib/active_support/callbacks.rb
+++ b/activesupport/lib/active_support/callbacks.rb
@@ -806,30 +806,30 @@ module ActiveSupport
         def define_callbacks(*names)
           options = names.extract_options!
 
-          ([self] + ActiveSupport::DescendantsTracker.descendants(self)).each do |target|
-            names.each do |name|
-              name = name.to_sym
+          names.each do |name|
+            name = name.to_sym
 
+            ([self] + ActiveSupport::DescendantsTracker.descendants(self)).each do |target|
               target.set_callbacks name, CallbackChain.new(name, options)
+            end
 
-              target.module_eval <<-RUBY, __FILE__, __LINE__ + 1
-                def _run_#{name}_callbacks(&block)
-                  run_callbacks #{name.inspect}, &block
-                end
+            module_eval <<-RUBY, __FILE__, __LINE__ + 1
+              def _run_#{name}_callbacks(&block)
+                run_callbacks #{name.inspect}, &block
+              end
 
-                def self._#{name}_callbacks
-                  get_callbacks(#{name.inspect})
-                end
+              def self._#{name}_callbacks
+                get_callbacks(#{name.inspect})
+              end
 
-                def self._#{name}_callbacks=(value)
-                  set_callbacks(#{name.inspect}, value)
-                end
+              def self._#{name}_callbacks=(value)
+                set_callbacks(#{name.inspect}, value)
+              end
 
-                def _#{name}_callbacks
-                  __callbacks[#{name.inspect}]
-                end
-              RUBY
-            end
+              def _#{name}_callbacks
+                __callbacks[#{name.inspect}]
+              end
+            RUBY
           end
         end