Avoid scoping update transaction when calling update! on a relation

This makes scoping consistent with ActiveRecord::Relation#update.
ActiveRecord::Relation#update was defined specifically to avoid this
unexpected scoping in Active Record callbacks triggered from the update
which otherwise get introduced by ActiveRecord::Relation#method_missing.

activerecord/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   Avoid scoping update callbacks in `ActiveRecord::Relation#update!`.
+
+    Making it consistent with how scoping is applied only to the query in `ActiveRecord::Relation#update`
+    and not also to the callbacks from the update itself.
+
+    *Dylan Thacker-Smith*
+
 *   Fix 2 cases that inferred polymorphic class from the association's `foreign_type`
     using `String#constantize` instead of the model's `polymorphic_class_for`.
 

activerecord/lib/active_record/relation.rb

@@ -498,6 +498,14 @@ module ActiveRecord
       end
     end
 
+    def update!(id = :all, attributes) # :nodoc:
+      if id == :all
+        each { |record| record.update!(attributes) }
+      else
+        klass.update!(id, attributes)
+      end
+    end
+
     # Updates the counters of the records in the current relation.
     #
     # ==== Parameters

activerecord/test/cases/relation/update_all_test.rb

@@ -173,6 +173,24 @@ class UpdateAllTest < ActiveRecord::TestCase
     end
   end
 
+  def test_update_bang_on_relation
+    topic1 = TopicWithCallbacks.create! title: "arel", author_name: nil
+    topic2 = TopicWithCallbacks.create! title: "activerecord", author_name: nil
+    topic3 = TopicWithCallbacks.create! title: "ar", author_name: nil
+    topics = TopicWithCallbacks.where(id: [topic1.id, topic2.id])
+    topics.update!(title: "adequaterecord")
+
+    assert_equal TopicWithCallbacks.count, TopicWithCallbacks.topic_count
+
+    assert_equal "adequaterecord", topic1.reload.title
+    assert_equal "adequaterecord", topic2.reload.title
+    assert_equal "ar", topic3.reload.title
+    # Testing that the before_update callbacks have run
+    assert_equal "David", topic1.reload.author_name
+    assert_equal "David", topic2.reload.author_name
+    assert_nil topic3.reload.author_name
+  end
+
   def test_update_all_cares_about_optimistic_locking
     david = people(:david)