1 files changed, 29 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/type/immutable_string.rb b/activemodel/lib/active_model/type/immutable_string.rb
new file mode 100644
index 0000000000..20b8ca0cc4
--- /dev/null
+++ b/activemodel/lib/active_model/type/immutable_string.rb
@@ -0,0 +1,29 @@
+module ActiveModel
+  module Type
+    class ImmutableString < Value # :nodoc:
+      def type
+        :string
+      end
+
+      def serialize(value)
+        case value
+        when ::Numeric, ActiveSupport::Duration then value.to_s
+        when true then "t"
+        when false then "f"
+        else super
+        end
+      end
+
+      private
+
+      def cast_value(value)
+        result = case value
+                 when true then "t"
+                 when false then "f"
+                 else value.to_s
+                 end
+        result.freeze
+      end
+    end
+  end
+end