lib/jsonapi/resource_serializer.rb in jsonapi-resources-0.3.0.pre2 vs lib/jsonapi/resource_serializer.rb in jsonapi-resources-0.3.0

@@ -248,9 +248,11 @@
       linkage = {}
       linkage_id = foreign_key_value(source, association)
       if linkage_id
         linkage[:type] = format_route(association.type)
         linkage[:id] = linkage_id
+      else
+        linkage = nil
       end
       linkage
     end
 
     def has_many_linkage(source, association)