fix: correct isEmpty method

Author: dukeluo

lib/utils/utility.js

@@ -41,7 +41,7 @@ const isNil = (x) => x === undefined || x === null;
  */
 const isEmpty = (x) =>
   x === '' ||
-  (isArray(x) && x.length) === 0 ||
+  (isArray(x) && x.length === 0) ||
   (isObject(x) && Object.keys(x).length === 0);
 
 /**