Merge pull request #24980 from merhard/virtual-attribute-default

Define ActiveRecord::Attribute::Null#type_cast

activerecord/lib/active_record/attribute.rb

@@ -170,7 +170,7 @@ def initialize(name)
         super(name, nil, Type::Value.new)
       end
 
-      def value
+      def type_cast(*)
         nil
       end
 

activerecord/test/cases/attributes_test.rb

@@ -63,6 +63,15 @@ class CustomPropertiesTest < ActiveRecord::TestCase
       end
     end
 
+    test "model with nonexistent attribute with default value can be saved" do
+      klass = Class.new(OverloadedType) do
+        attribute :non_existent_string_with_default, :string, default: 'nonexistent'
+      end
+
+      model = klass.new
+      assert model.save
+    end
+
     test "changing defaults" do
       data = OverloadedType.new
       unoverloaded_data = UnoverloadedType.new