Refs #28025 nullify *_type column on polymorphic associations on :nu… (#28078)

This PR addresses the issue described in #28025. On `dependent: :nullify` strategy only the foreign key of the relation is nullified. However on polymorphic associations the  `*_type` column is not nullified leaving the record with a NULL `*_id` but the `*_type` column is present.

2 files changed, 11 insertions, 0 deletions

diff --git a/activerecord/test/models/drink_designer.rb b/activerecord/test/models/drink_designer.rb
index eb6701b84e..8258408f35 100644
--- a/activerecord/test/models/drink_designer.rb
+++ b/activerecord/test/models/drink_designer.rb
@@ -4,5 +4,11 @@ class DrinkDesigner < ActiveRecord::Base
   has_one :chef, as: :employable
 end
 
+class DrinkDesignerWithPolymorphicDependentNullifyChef < ActiveRecord::Base
+  self.table_name = "drink_designers"
+
+  has_one :chef, as: :employable, dependent: :nullify
+end
+
 class MocktailDesigner < DrinkDesigner
 end
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index 5cba1e440e..c3d15a571a 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -62,6 +62,11 @@ class PersonWithDependentNullifyJobs < ActiveRecord::Base
   has_many :jobs, source: :job, through: :references, dependent: :nullify
 end
 
+class PersonWithPolymorphicDependentNullifyComments < ActiveRecord::Base
+  self.table_name = "people"
+  has_many :comments, as: :author, dependent: :nullify
+end
+
 class LoosePerson < ActiveRecord::Base
   self.table_name = "people"
   self.abstract_class = true