1 files changed, 51 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/attribute/user_provided_default.rb b/activemodel/lib/active_model/attribute/user_provided_default.rb
new file mode 100644
index 0000000000..9dc16e882d
--- /dev/null
+++ b/activemodel/lib/active_model/attribute/user_provided_default.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require "active_model/attribute"
+
+module ActiveModel
+  class Attribute # :nodoc:
+    class UserProvidedDefault < FromUser # :nodoc:
+      def initialize(name, value, type, database_default)
+        @user_provided_value = value
+        super(name, value, type, database_default)
+      end
+
+      def value_before_type_cast
+        if user_provided_value.is_a?(Proc)
+          @memoized_value_before_type_cast ||= user_provided_value.call
+        else
+          @user_provided_value
+        end
+      end
+
+      def with_type(type)
+        self.class.new(name, user_provided_value, type, original_attribute)
+      end
+
+      def marshal_dump
+        result = [
+          name,
+          value_before_type_cast,
+          type,
+          original_attribute,
+        ]
+        result << value if defined?(@value)
+        result
+      end
+
+      def marshal_load(values)
+        name, user_provided_value, type, original_attribute, value = values
+        @name = name
+        @user_provided_value = user_provided_value
+        @type = type
+        @original_attribute = original_attribute
+        if values.length == 5
+          @value = value
+        end
+      end
+
+      private
+        attr_reader :user_provided_value
+    end
+  end
+end