arrow function syntax (=>)' is only available in ES6 (use 'esversion: 6')

Sol 1:- 

/* jshint esnext : true */

https://community.servicenow.com/community?id=community_question&sys_id=7f290fe1db5cdbc01dcaf3231f961990

Sol 2:-

I was able to resolve this issue by adding this block of code at the top of each file.js that accused the error

/*jshint esversion: 6 */

https://stackoverflow.com/questions/42866159/arrow-function-syntax-is-only-available-in-es6-use-esversion-6