Transform part of a string in Javascript

https://stackoverflow.com/questions/45253127/transform-part-of-a-string-in-javascript/45253757

by codemeasandwich

JavaScript

const cssnew =  ` @media (max-width: 600px) {   color: red;    }`
const pattern = /(@media[^{]+{\s*)([\s\S]+?)(\s*})/g

console.log(cssnew.replace( pattern, "$1.foo{\n\t\t$2\n\t}$3" ));