Merge pull request #52305 from joshuay03/fix-52304

[Fix #52304] Avoid computing `klass` if reflection is a `belongs_to` in `ActiveRecord::AutosaveAssociation#inverse_belongs_to_association_for`

activerecord/lib/active_record/autosave_association.rb

@@ -467,6 +467,7 @@ def save_has_one_association(reflection)
       end
 
       def inverse_belongs_to_association_for(reflection, record)
+        !reflection.belongs_to? &&
           reflection.inverse_of &&
           reflection.inverse_of.belongs_to? &&
           record.association(reflection.inverse_of.name)

activerecord/test/cases/autosave_association_test.rb

@@ -305,7 +305,7 @@ def test_callbacks_firing_order_on_save
   end
 
   def test_callbacks_on_child_when_parent_autosaves_child
-    eye = Eye.create(iris: Iris.new)
+    eye = Eye.create!(iris: Iris.new)
     assert_equal 1, eye.iris.before_validation_callbacks_counter
     assert_equal 1, eye.iris.before_create_callbacks_counter
     assert_equal 1, eye.iris.before_save_callbacks_counter
@@ -314,8 +314,18 @@ def test_callbacks_on_child_when_parent_autosaves_child
     assert_equal 1, eye.iris.after_save_callbacks_counter
   end
 
+  def test_callbacks_on_child_when_parent_autosaves_polymorphic_child_with_inverse_of
+    drink_designer = DrinkDesigner.create!(chef: ChefWithPolymorphicInverseOf.new)
+    assert_equal 1, drink_designer.chef.before_validation_callbacks_counter
+    assert_equal 1, drink_designer.chef.before_create_callbacks_counter
+    assert_equal 1, drink_designer.chef.before_save_callbacks_counter
+    assert_equal 1, drink_designer.chef.after_validation_callbacks_counter
+    assert_equal 1, drink_designer.chef.after_create_callbacks_counter
+    assert_equal 1, drink_designer.chef.after_save_callbacks_counter
+  end
+
   def test_callbacks_on_child_when_child_autosaves_parent
-    iris = Iris.create(eye: Eye.new)
+    iris = Iris.create!(eye: Eye.new)
     assert_equal 1, iris.before_validation_callbacks_counter
     assert_equal 1, iris.before_create_callbacks_counter
     assert_equal 1, iris.before_save_callbacks_counter
@@ -324,6 +334,16 @@ def test_callbacks_on_child_when_child_autosaves_parent
     assert_equal 1, iris.after_save_callbacks_counter
   end
 
+  def test_callbacks_on_child_when_polymorphic_child_with_inverse_of_autosaves_parent
+    chef = ChefWithPolymorphicInverseOf.create!(employable: DrinkDesigner.new)
+    assert_equal 1, chef.before_validation_callbacks_counter
+    assert_equal 1, chef.before_create_callbacks_counter
+    assert_equal 1, chef.before_save_callbacks_counter
+    assert_equal 1, chef.after_validation_callbacks_counter
+    assert_equal 1, chef.after_create_callbacks_counter
+    assert_equal 1, chef.after_save_callbacks_counter
+  end
+
   def test_foreign_key_attribute_is_not_set_unless_changed
     eye = Eye.create!(iris_with_read_only_foreign_key_attributes: { color: "honey" })
     assert_nothing_raised do

activerecord/test/models/chef.rb

@@ -8,3 +8,55 @@ class Chef < ActiveRecord::Base
 class ChefList < Chef
   belongs_to :employable_list, polymorphic: true
 end
+
+class ChefWithPolymorphicInverseOf < Chef
+  attr_reader :before_validation_callbacks_counter
+  attr_reader :before_create_callbacks_counter
+  attr_reader :before_save_callbacks_counter
+
+  attr_reader :after_validation_callbacks_counter
+  attr_reader :after_create_callbacks_counter
+  attr_reader :after_save_callbacks_counter
+
+  belongs_to :employable, polymorphic: true, inverse_of: :chef
+  accepts_nested_attributes_for :employable
+
+  before_validation :update_before_validation_counter
+  before_create :update_before_create_counter
+  before_save :update_before_save_counter
+
+  after_validation :update_after_validation_counter
+  after_create :update_after_create_counter
+  after_save :update_after_save_counter
+
+  private
+    def update_before_validation_counter
+      @before_validation_callbacks_counter ||= 0
+      @before_validation_callbacks_counter += 1
+    end
+
+    def update_before_create_counter
+      @before_create_callbacks_counter ||= 0
+      @before_create_callbacks_counter += 1
+    end
+
+    def update_before_save_counter
+      @before_save_callbacks_counter ||= 0
+      @before_save_callbacks_counter += 1
+    end
+
+    def update_after_validation_counter
+      @after_validation_callbacks_counter ||= 0
+      @after_validation_callbacks_counter += 1
+    end
+
+    def update_after_create_counter
+      @after_create_callbacks_counter ||= 0
+      @after_create_callbacks_counter += 1
+    end
+
+    def update_after_save_counter
+      @after_save_callbacks_counter ||= 0
+      @after_save_callbacks_counter += 1
+    end
+end

activerecord/test/models/drink_designer.rb

@@ -2,6 +2,7 @@
 
 class DrinkDesigner < ActiveRecord::Base
   has_one :chef, as: :employable
+  accepts_nested_attributes_for :chef
 end
 
 class DrinkDesignerWithPolymorphicDependentNullifyChef < ActiveRecord::Base