Detect whether there is ES6 (ES2015) new syntax in the js code file.
It can also detect new syntax such as ES7, ES8, ES9, and ES10.
The new syntaxes that support detection are: ES6(2015), ES7(2016), ES8(2017), ES9(2018), ES10(2019), ES11(2020), ES12(2021), ES13(2022), ES14(2023), or "latest"
based acorn.js.
If you need to convert ES6 to ES5 online, you can use ES6 to ES5.