If a counter_cache is defined, then using update_attributes and changing

the primary key on an association will make sure that the corresponding
counter on the association is changed properly. Fixes #9722.

1 files changed, 31 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 1ddd380f23..781b87741d 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -789,6 +789,37 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_calling_update_attributes_on_id_changes_the_counter_cache
+    topic = Topic.order("id ASC").first
+    original_count = topic.replies.to_a.size
+    assert_equal original_count, topic.replies_count
+
+    first_reply = topic.replies.first
+    first_reply.update_attributes(:parent_id => nil)
+    assert_equal original_count - 1, topic.reload.replies_count
+
+    first_reply.update_attributes(:parent_id => topic.id)
+    assert_equal original_count, topic.reload.replies_count
+  end
+
+  def test_calling_update_attributes_changing_ids_doesnt_change_counter_cache
+    topic1 = Topic.find(1)
+    topic2 = Topic.find(3)
+    original_count1 = topic1.replies.to_a.size
+    original_count2 = topic2.replies.to_a.size
+
+    reply1 = topic1.replies.first
+    reply2 = topic2.replies.first
+
+    reply1.update_attributes(:parent_id => topic2.id)
+    assert_equal original_count1 - 1, topic1.reload.replies_count
+    assert_equal original_count2 + 1, topic2.reload.replies_count
+
+    reply2.update_attributes(:parent_id => topic1.id)
+    assert_equal original_count1, topic1.reload.replies_count
+    assert_equal original_count2, topic2.reload.replies_count
+  end
+
   def test_deleting_a_collection
     force_signal37_to_load_all_clients_of_firm
     companies(:first_firm).clients_of_firm.create("name" => "Another Client")