@platox/postcss-replace/lib/pixel-unit-regex.js

A CSS post-processor that converts px to rem.

// excluding regex trick: http://www.rexegg.com/regex-best-trick.html

// Not anything inside double quotes
// Not anything inside single quotes
// Not anything inside url()
// Any digit followed by px
// !singlequotes|!doublequotes|!url()|pixelunit

module.exports = (unit) =>
  new RegExp(
    `"[^"]+"|'[^']+'|url\\([^)]+\\)|var\\([^)]+\\)|(\\d*\\.?\\d+)${unit}`,
    'g',
  );