X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/07e4083ea451913b988d77e8e4c926da8ad844a4..267c1a22e4b9e04ed29d1360f4e7ea6519845d12:/services/api/lib/serializers.rb

diff --git a/services/api/lib/serializers.rb b/services/api/lib/serializers.rb
index 41379f308f..37734e0bb4 100644
--- a/services/api/lib/serializers.rb
+++ b/services/api/lib/serializers.rb
@@ -1,7 +1,17 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
 require 'safe_json'
 
 class Serializer
+  class TypeMismatch < ArgumentError
+  end
+
   def self.dump(val)
+    if !val.is_a?(object_class)
+      raise TypeMismatch.new("cannot serialize #{val.class} as #{object_class}")
+    end
     SafeJSON.dump(val)
   end
 
@@ -22,7 +32,10 @@ class Serializer
   end
 
   def self.load(s)
-    if s.nil?
+    if s.is_a?(object_class)
+      # Rails already deserialized for us
+      s
+    elsif s.nil?
       object_class.new()
     elsif s[0] == first_json_char
       SafeJSON.load(s)