Refactor serialized types to be partially defined as custom properties

Many of the methods defined in `AttributeMethods::Serialization` can be
refactored onto this type as well, but this is a reasonable small step.
Removes the `Type` class, and the need for `decorate_columns` to handle
serialized types.

1 files changed, 6 insertions, 20 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 47c6f94ba7..e8c27cb8b8 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -58,32 +58,18 @@ module ActiveRecord
                     Coders::YAMLColumn.new(class_name_or_coder)
                   end
 
+          type = columns_hash[attr_name.to_s].cast_type
+          if type.serialized?
+            type = type.subtype
+          end
+          property attr_name, ActiveRecord::Type::Serialized.new(type)
+
           # merge new serialized attribute and create new hash to ensure that each class in inheritance hierarchy
           # has its own hash of own serialized attributes
           self.serialized_attributes = serialized_attributes.merge(attr_name.to_s => coder)
         end
       end
 
-      class Type # :nodoc:
-        delegate :type, :type_cast_for_database, to: :@column
-
-        def initialize(column)
-          @column = column
-        end
-
-        def type_cast(value)
-          if value.state == :serialized
-            value.unserialized_value @column.type_cast value.value
-          else
-            value.unserialized_value
-          end
-        end
-
-        def accessor
-          ActiveRecord::Store::IndifferentHashAccessor
-        end
-      end
-
       class Attribute < Struct.new(:coder, :value, :state) # :nodoc:
         def unserialized_value(v = value)
           state == :serialized ? unserialize(v) : value