Merge pull request feathersjs-ecosystem#428 from bertho-zero/patch-3

Update alter-items.js

Author: eddyystop

lib/services/alter-items.js

@@ -17,7 +17,9 @@ module.exports = function (func) {
 
     const results = (isArray ? items : [items]).map(item => func(item, context));
 
-    const hasPromises = results.some(result => typeof result === 'object' && typeof result.then === 'function');
+    const hasPromises = results.some(result =>
+      typeof result === 'object' && result !== null && typeof result.then === 'function'
+    );
 
     const setItem = (value, index) => {
       if (typeof value === 'object' && value !== null) {