Merge pull request #12450 from iantropov/master

Fix bug, when ':dependent => :destroy' violates foreign key constraints

Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/associations/builder/association.rb
	activerecord/lib/active_record/associations/builder/has_one.rb

activerecord/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   Move 'dependent: :destroy' handling for 'belongs_to'
+    from 'before_destroy' to 'after_destroy' callback chain
+
+    Fix #12380.
+
+    *Ivan Antropov*
+
 *   Detect in-place modifications on String attributes.
 
     Before this change user have to mark the attribute as changed to it be persisted

activerecord/lib/active_record/associations/builder/association.rb

@@ -85,7 +85,11 @@ module ActiveRecord::Associations::Builder
     end
 
     def self.define_callbacks(model, reflection)
-      add_before_destroy_callbacks(model, reflection) if reflection.options[:dependent]
+      if dependent = reflection.options[:dependent]
+        check_dependent_options(dependent)
+        add_destroy_callbacks(model, reflection)
+      end
+
       Association.extensions.each do |extension|
         extension.build model, reflection
       end
@@ -126,11 +130,13 @@ module ActiveRecord::Associations::Builder
 
     private
 
-    def self.add_before_destroy_callbacks(model, reflection)
-      unless valid_dependent_options.include? reflection.options[:dependent]
-        raise ArgumentError, "The :dependent option must be one of #{valid_dependent_options}, but is :#{reflection.options[:dependent]}"
+    def self.check_dependent_options(dependent)
+      unless valid_dependent_options.include? dependent
+        raise ArgumentError, "The :dependent option must be one of #{valid_dependent_options}, but is :#{dependent}"
       end
+    end
 
+    def self.add_destroy_callbacks(model, reflection)
       name = reflection.name
       model.before_destroy lambda { |o| o.association(name).handle_dependency }
     end

activerecord/lib/active_record/associations/builder/belongs_to.rb

@@ -107,5 +107,10 @@ module ActiveRecord::Associations::Builder
       model.after_touch   callback
       model.after_destroy callback
     end
+
+    def self.add_destroy_callbacks(model, reflection)
+      name = reflection.name
+      model.after_destroy lambda { |o| o.association(name).handle_dependency }
+    end
   end
 end

activerecord/lib/active_record/associations/builder/has_one.rb

@@ -16,7 +16,7 @@ module ActiveRecord::Associations::Builder
 
     private
 
-    def self.add_before_destroy_callbacks(model, reflection)
+    def self.add_destroy_callbacks(model, reflection)
       super unless reflection.options[:through]
     end
   end

activerecord/test/cases/associations/belongs_to_associations_test.rb

@@ -935,3 +935,39 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, Column.count
   end
 end
+
+class BelongsToWithForeignKeyTest < ActiveRecord::TestCase
+  def setup
+    ActiveRecord::Schema.define do
+      drop_table :authors, if_exists: true
+      drop_table :author_addresses, if_exists: true
+
+      create_table :author_addresses do |t|
+      end
+
+      exec_query  <<-eos
+        create table authors(
+          id int,
+          author_address_id int,
+          name varchar(255),
+          PRIMARY KEY (id),
+          FOREIGN KEY (author_address_id) REFERENCES author_addresses(id)
+        );
+      eos
+    end
+  end
+
+  def teardown
+    ActiveRecord::Schema.define do
+      drop_table :authors, if_exists: true
+      drop_table :author_addresses, if_exists: true
+    end
+  end
+
+  def test_destroy_linked_models
+    address = AuthorAddress.create!
+    author = Author.create! id: 1, name: "Author", author_address_id: address.id
+
+    author.destroy!
+  end
+end