Fix PostgreSQL Uuid#change? to ignore uuid's value formatting

activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb

@@ -6,6 +6,7 @@ module PostgreSQL
       module OID # :nodoc:
         class Uuid < Type::Value # :nodoc:
           ACCEPTABLE_UUID = %r{\A(\{)?([a-fA-F0-9]{4}-?){8}(?(1)\}|)\z}
+          CANONICAL_UUID = %r{\A[0-9a-f]{8}-(?:[0-9a-f]{4}-){3}[0-9a-f]{12}\z}
 
           alias :serialize :deserialize
 
@@ -15,18 +16,27 @@ def type
 
           def changed?(old_value, new_value, _new_value_before_type_cast)
             old_value.class != new_value.class ||
-              new_value && old_value.casecmp(new_value) != 0
+              new_value != old_value
           end
 
           def changed_in_place?(raw_old_value, new_value)
             raw_old_value.class != new_value.class ||
-              new_value && raw_old_value.casecmp(new_value) != 0
+              new_value != raw_old_value
           end
 
           private
             def cast_value(value)
-              casted = value.to_s
-              casted if casted.match?(ACCEPTABLE_UUID)
+              value = value.to_s
+              format_uuid(value) if value.match?(ACCEPTABLE_UUID)
+            end
+
+            def format_uuid(uuid)
+              if uuid.match?(CANONICAL_UUID)
+                uuid
+              else
+                uuid = uuid.delete("{}-").downcase
+                "#{uuid[..7]}-#{uuid[8..11]}-#{uuid[12..15]}-#{uuid[16..19]}-#{uuid[20..]}"
+              end
             end
         end
       end

activerecord/test/cases/adapters/postgresql/uuid_test.rb

@@ -121,10 +121,13 @@ def test_invalid_uuid_dont_match_to_nil
     assert_empty UUIDType.where(guid: "foobar")
   end
 
-  def test_uuid_change_case_does_not_mark_dirty
+  def test_uuid_change_format_does_not_mark_dirty
     model = UUIDType.create!(guid: "abcd-0123-4567-89ef-dead-beef-0101-1010")
     model.guid = model.guid.swapcase
     assert_not_predicate model, :changed?
+
+    model.guid = "{#{model.guid}}"
+    assert_not_predicate model, :changed?
   end
 
   class DuckUUID