fix: handle array values in stringify

Author: anonrig

lib/stringify.js

@@ -21,9 +21,9 @@ function getAsPrimitive(value) {
 }
 
 /**
- * @callback
- * @param {any} input
- * @return {string}
+ * @param {Record<string, string | number | boolean
+ * | ReadonlyArray<string | number | boolean> | null>} input
+ * @returns {string}
  */
 function stringify(input) {
   let result = "";
@@ -32,9 +32,9 @@ function stringify(input) {
     return result;
   }
 
-  const keys = Object.getOwnPropertyNames(input);
-  const keyLength = keys.length;
   const separator = "&";
+  const keys = Object.keys(input);
+  const keyLength = keys.length;
   let valueLength = 0;
 
   for (let i = 0; i < keyLength; i++) {