Cleanup

node_modules/mongoose/lib/helpers/projection/isExclusive.js

@@ -7,6 +7,10 @@ const isDefiningProjection = require('./isDefiningProjection');
  */
 
 module.exports = function isExclusive(projection) {
+  if (projection == null) {
+    return null;
+  }
+
   const keys = Object.keys(projection);
   let ki = keys.length;
   let exclude = null;