postcssContentHashPlugin.js

// https://github.com/postcss/postcss-plugin-boilerplate/

const CryptoJS = require('crypto-js');

module.exports = (_opts = {}) => {
  return {
    postcssPlugin: 'content-hash',
    Root(root, _postcss) {
      const contentHash = CryptoJS.MD5(root.source.input.css);
      root.prepend({ text: `content-hash:${contentHash}` });
    },
  };
};

module.exports.postcss = true;