Revert "Merge pull request #39929 from jonathanhefner/decorate-original-attribute-type"

This reverts commit 79d0c17c65, reversing
changes made to bc828f74df.

Fixes #41138.

activerecord/lib/active_record/attribute_methods/serialization.rb

@@ -128,7 +128,7 @@ module ActiveRecord
             Coders::YAMLColumn.new(attr_name, class_name_or_coder)
           end
 
-          attribute(attr_name, **options) do |cast_type|
+          decorate_attribute_type(attr_name.to_s, **options) do |cast_type|
             if type_incompatible_with_serialize?(cast_type, class_name_or_coder)
               raise ColumnNotSerializableError.new(attr_name, cast_type)
             end

activerecord/lib/active_record/attributes.rb

@@ -208,21 +208,14 @@ module ActiveRecord
       # tracking is performed. The methods +changed?+ and +changed_in_place?+
       # will be called from ActiveModel::Dirty. See the documentation for those
       # methods in ActiveModel::Type::Value for more details.
-      def attribute(name, cast_type = nil, **options, &decorator)
+      def attribute(name, cast_type = nil, **options, &block)
         name = name.to_s
         reload_schema_from_cache
 
-        prev_cast_type, prev_options, prev_decorator = attributes_to_define_after_schema_loads[name]
-
-        unless cast_type && prev_cast_type
-          cast_type ||= prev_cast_type
-          options = prev_options || options if options.empty?
-          decorator ||= prev_decorator
-        end
-
-        self.attributes_to_define_after_schema_loads = attributes_to_define_after_schema_loads.merge(
-          name => [cast_type, options, decorator]
-        )
+        self.attributes_to_define_after_schema_loads =
+          attributes_to_define_after_schema_loads.merge(
+            name => [cast_type || block, options]
+          )
       end
 
       # This is the low level API which sits beneath +attribute+. It only
@@ -255,16 +248,8 @@ module ActiveRecord
 
       def load_schema! # :nodoc:
         super
-        attributes_to_define_after_schema_loads.each do |name, (type, options, decorator)|
-          if type.is_a?(Symbol)
-            type = ActiveRecord::Type.lookup(type, **options.except(:default), adapter: ActiveRecord::Type.adapter_name_from(self))
-          elsif type.nil?
-            type = type_for_attribute(name)
-          end
-
-          type = decorator[type] if decorator
-
-          define_attribute(name, type, **options.slice(:default))
+        attributes_to_define_after_schema_loads.each do |name, (type, options)|
+          define_attribute(name, _lookup_cast_type(name, type, options), **options.slice(:default))
         end
       end
 
@@ -287,6 +272,32 @@ module ActiveRecord
           end
           _default_attributes[name] = default_attribute
         end
+
+        def decorate_attribute_type(attr_name, **default)
+          type, options = attributes_to_define_after_schema_loads[attr_name]
+
+          default.with_defaults!(default: options[:default]) if options&.key?(:default)
+
+          attribute(attr_name, **default) do |cast_type|
+            if type && !type.is_a?(Proc)
+              cast_type = _lookup_cast_type(attr_name, type, options)
+            end
+
+            yield cast_type
+          end
+        end
+
+        def _lookup_cast_type(name, type, options)
+          case type
+          when Symbol
+            adapter_name = ActiveRecord::Type.adapter_name_from(self)
+            ActiveRecord::Type.lookup(type, **options.except(:default), adapter: adapter_name)
+          when Proc
+            type[type_for_attribute(name)]
+          else
+            type || type_for_attribute(name)
+          end
+        end
     end
   end
 end

activerecord/lib/active_record/enum.rb

@@ -181,7 +181,7 @@ module ActiveRecord
 
         attr = attribute_alias?(name) ? attribute_alias(name) : name
 
-        attribute(attr, **default) do |subtype|
+        decorate_attribute_type(attr, **default) do |subtype|
           EnumType.new(attr, enum_values, subtype)
         end
 

activerecord/test/cases/attributes_test.rb

@@ -68,15 +68,6 @@ module ActiveRecord
       assert_equal "the overloaded default", klass.new.overloaded_string_with_limit
     end
 
-    test "attributes with overridden types keep their type when a default value is configured separately" do
-      child = Class.new(OverloadedType) do
-        attribute :overloaded_float, default: "123"
-      end
-
-      assert_equal OverloadedType.type_for_attribute("overloaded_float"), child.type_for_attribute("overloaded_float")
-      assert_equal 123, child.new.overloaded_float
-    end
-
     test "extra options are forwarded to the type caster constructor" do
       klass = Class.new(OverloadedType) do
         attribute :starts_at, :datetime, precision: 3, limit: 2, scale: 1, default: -> { Time.now.utc }
@@ -304,15 +295,6 @@ module ActiveRecord
       assert_equal 123, model.non_existent_decimal
     end
 
-    test "attributes not backed by database columns keep their type when a default value is configured separately" do
-      child = Class.new(OverloadedType) do
-        attribute :non_existent_decimal, default: "123"
-      end
-
-      assert_equal OverloadedType.type_for_attribute("non_existent_decimal"), child.type_for_attribute("non_existent_decimal")
-      assert_equal 123, child.new.non_existent_decimal
-    end
-
     test "attributes not backed by database columns properly interact with mutation and dirty" do
       child = Class.new(ActiveRecord::Base) do
         self.table_name = "topics"