do not ignore decode errors

lib/resque/helpers.rb

@@ -1,6 +1,8 @@
 module Resque
   # Methods used by various classes in Resque.
   module Helpers
+    class DecodeException < StandardError; end
+
     # Direct access to the Redis instance.
     def redis
       Resque.redis
@@ -23,12 +25,14 @@ def decode(object)
       if defined? Yajl
         begin
           Yajl::Parser.parse(object, :check_utf8 => false)
-        rescue Yajl::ParseError
+        rescue Yajl::ParseError => e
+          raise DecodeException, e
         end
       else
         begin
           JSON.parse(object)
-        rescue JSON::ParserError
+        rescue JSON::ParserError => e
+          raise DecodeException, e
         end
       end
     end

test/resque_test.rb

@@ -233,6 +233,8 @@
   end
 
   test "decode bad json" do
-    assert_nil Resque.decode("{\"error\":\"Module not found \\u002\"}")
+    assert_raises Resque::Helpers::DecodeException do
+      Resque.decode("{\"error\":\"Module not found \\u002\"}")
+    end
   end
 end