babel postcss literal plugin

postcss.js

const deasync = require('deasync-promise');
const postcss = require('postcss');
const postcssrc = require('postcss-load-config');

module.exports = ({ ctx }) => {
  return {
    visitor: {
      TaggedTemplateExpression({ node }, { file }) {
        if (node.tag.name !== 'css') return;

        for ({ value } of node.quasi.quasis) {
          const { plugins, options } = deasync(postcssrc(ctx));
          const { css } = deasync(
            postcss(plugins).process(value.raw, { ...options, from: file.opts.filename }),
          );

          value.raw = css;
        }
      },
    },
  };
};