[internals] check for string type else return early

lib/utils/index.js

@@ -196,6 +196,7 @@ export function noop(): void {}
  * @returns {*}
  */
 export function stripTrailingSlash(str: string): string {
+  if (!isString(str)) return str;
   return str.endsWith('/') ? str.slice(0, -1) : str;
 }