postcss-discard-empty/src/index.js

'use strict';
const plugin = 'postcss-discard-empty';

function discardAndReport(css, result) {
  function discardEmpty(node) {
    const { type, nodes: sub, params } = node;

    if (sub) {
      node.each(discardEmpty);
    }

    if (
      (type === 'decl' && !node.value) ||
      (type === 'rule' && !node.selector) ||
      (sub && !sub.length) ||
      (type === 'atrule' && ((!sub && !params) || (!params && !sub.length)))
    ) {
      node.remove();

      result.messages.push({
        type: 'removal',
        plugin,
        node,
      });
    }
  }

  css.each(discardEmpty);
}

function pluginCreator() {
  return {
    postcssPlugin: plugin,
    OnceExit(css, { result }) {
      discardAndReport(css, result);
    },
  };
}

pluginCreator.postcss = true;
module.exports = pluginCreator;