1 files changed, 39 insertions, 0 deletions
diff --git a/activerecord/test/models/eye.rb b/activerecord/test/models/eye.rb
new file mode 100644
index 0000000000..f3608b62ef
--- /dev/null
+++ b/activerecord/test/models/eye.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class Eye < ActiveRecord::Base
+  attr_reader :after_create_callbacks_stack
+  attr_reader :after_update_callbacks_stack
+  attr_reader :after_save_callbacks_stack
+
+  # Callbacks configured before the ones has_one sets up.
+  after_create :trace_after_create
+  after_update :trace_after_update
+  after_save   :trace_after_save
+
+  has_one :iris
+  accepts_nested_attributes_for :iris
+
+  # Callbacks configured after the ones has_one sets up.
+  after_create :trace_after_create2
+  after_update :trace_after_update2
+  after_save   :trace_after_save2
+
+  def trace_after_create
+    (@after_create_callbacks_stack ||= []) << !iris.persisted?
+  end
+  alias trace_after_create2 trace_after_create
+
+  def trace_after_update
+    (@after_update_callbacks_stack ||= []) << iris.has_changes_to_save?
+  end
+  alias trace_after_update2 trace_after_update
+
+  def trace_after_save
+    (@after_save_callbacks_stack ||= []) << iris.has_changes_to_save?
+  end
+  alias trace_after_save2 trace_after_save
+end
+
+class Iris < ActiveRecord::Base
+  belongs_to :eye
+end