Cast a value to a list if it's a string

code/backend/beacon/beacon.py

@@ -56,8 +56,10 @@ class Beacon(object):
                 response['datasetAlleleResponses'].append(allele_response)
 
     def dispatch_query(self, query: dict, user_groups: List[str]):
-        dataset_ids = query.get('datasetIds', [])
         beacon_id = self.settings.get_beacon_information().get('id')
+        dataset_ids = query.get('datasetIds', [])
+        if not isinstance(dataset_ids, list):
+            dataset_ids = [dataset_ids]
 
         try:
             validate_input(**query)