Merge pull request holidayextras#22 from holidayextras/fix-index-creation

Fix index creation

Author: pmcnr-hx

lib/mongoHandler.js

@@ -147,16 +147,20 @@ MongoStore._unknownError = function(err) {
   };
 };
 
-
 MongoStore.prototype._createIndexesForRelationships = function(collection, relationshipAttributeNames) {
+  if (!Array.isArray(relationshipAttributeNames) || !relationshipAttributeNames.length) return;
+
   var index = relationshipAttributeNames.reduce(function(partialIndex, name) {
-    partialIndex[name + ".id"] = 1;
+    if (name) {
+      partialIndex[name + ".id"] = 1;
+    }
     return partialIndex;
   }, {});
-  collection.createIndex(index);
+  if (Object.keys(index).length) {
+    collection.createIndex(index);
+  }
 };
 
-
 MongoStore.prototype._applySort = function(request, cursor) {
   if (!request.params.sort) return cursor;