source: frontend/node_modules/postcss-browser-comments/index.mjs

import browserslist from 'browserslist';

const plugin = opts => {
  return {
    postcssPlugin: 'postcss-browser-comments',

    Once(root) {
      // client browserslist
      const clientBrowserList = browserslist(Object(opts).browsers || null, {
        path: root.source && root.source.input && root.source.input.file
      }); // root children references

      const references = root.nodes.slice(0); // for each child node of the root children references

      for (const node of references) {
        // if the node is a comment browser comment node
        if (isBrowserCommentNode(node)) {
          // rule following the browser comment
          const rule = node.next(); // browser data

          const browserdata = getBrowserData(node.text);

          if (browserdata.isNumbered) {
            rule.nodes.filter(isBrowserReferenceCommentNode).map(comment => {
              const browserdataIndex = parseFloat(comment.text) - 1;
              const browserslistPart = browserdata.browserslist[browserdataIndex]; // whether to remove the rule if the comment browserslist does not match the client browserslist

              const removeRule = !clientBrowserList.some(clientBrowser => browserslist(browserslistPart).some(commentBrowser => commentBrowser === clientBrowser)); // conditionally remove the declaration and reference comment

              if (removeRule) {
                comment.prev().remove();
                comment.remove();
              }
            }); // conditionally remove the empty rule and comment

            if (!rule.nodes.length) {
              rule.remove();
              node.remove();
            }
          } else {
            // whether to remove the rule if the comment browserslist does not match the client browserslist
            const removeRule = !clientBrowserList.some(clientBrowser => browserslist(browserdata.browserslist).some(commentBrowser => commentBrowser === clientBrowser)); // conditionally remove the rule and comment

            if (removeRule) {
              rule.remove();
              node.remove();
            }
          }
        }
      }
    }

  };
};

plugin.postcss = true;

const isBrowserCommentNode = node => node.type === 'comment' && isBrowserCommentNodeRegExp.test(node.text) && node.next().type === 'rule';

const isBrowserCommentNodeRegExp = /^\*\n * /; // returns whether a node is a browser reference comment

const isBrowserReferenceCommentNode = node => node.type === 'comment' && isBrowserReferenceCommentNodeRegExp.test(node.text);

const isBrowserReferenceCommentNodeRegExp = /^\d+$/; // returns browser data from comment text

const getBrowserData = text => {
  const browserDataNumbered = text.match(browserDataMutliRegExp);
  const isNumbered = Boolean(browserDataNumbered);
  return {
    browserslist: isNumbered ? browserDataNumbered.map(browserslistPart => getBrowsersList(browserslistPart.replace(browserDataNumberedNewlineRegExp, '$1'))) : getBrowsersList(text.replace(browserDataNewlineRegExp, '')),
    isNumbered
  };
};

const browserDataMutliRegExp = /(\n \* \d+\. (?:[^\n]+|\n \* {4,})+)/g;
const browserDataNewlineRegExp = /^\*\n \* ?|\n \*/g;
const browserDataNumberedNewlineRegExp = /\n \* (?:( )\s*)?/g; // returns a browserlist from comment text

const getBrowsersList = text => text.split(getBrowsersListInSplitRegExp).slice(1).map(part => part.split(getBrowsersListAndSplitRegExp).filter(part2 => part2)).reduce((acc, val) => acc.concat(val), []).map(part => part.replace(getBrowsersListQueryRegExp, ($0, browser, query) => browser === 'all' ? '> 0%' : `${browser}${query ? /^((?:\d*\.)?\d+)-$/.test(query) ? ` <= ${query.slice(0, -1)}` : ` ${query}` : ' > 0'}`).toLowerCase());

const getBrowsersListInSplitRegExp = /\s+in\s+/;
const getBrowsersListAndSplitRegExp = /(?: and|, and|,)/;
const getBrowsersListQueryRegExp = /^\s*(\w+)(?: ((?:(?:\d*\.)?\d+-)?(?:\d*\.)?\d+[+-]?))?.*$/;

export default plugin;
//# sourceMappingURL=index.mjs.map