Don't query the database schema when calling `serialize`

We need to decorate the types lazily. This is extracted to a separate
API, as there are other refactorings that will be able to make use of
it, and to allow unit testing the finer points more granularly.

1 files changed, 7 insertions, 0 deletions

diff --git a/activerecord/test/cases/serialized_attribute_test.rb b/activerecord/test/cases/serialized_attribute_test.rb
index debb227303..7d1c240638 100644
--- a/activerecord/test/cases/serialized_attribute_test.rb
+++ b/activerecord/test/cases/serialized_attribute_test.rb
@@ -14,6 +14,13 @@ class SerializedAttributeTest < ActiveRecord::TestCase
     Topic.serialize("content")
   end
 
+  def test_serialize_does_not_eagerly_load_columns
+    assert_no_queries do
+      Topic.reset_column_information
+      Topic.serialize(:content)
+    end
+  end
+
   def test_list_of_serialized_attributes
     assert_equal %w(content), Topic.serialized_attributes.keys
   end