function fixMarkup(html) {
    if (!(options.tabReplace || options.useBR)) {
      return html;
    }

    return html.replace(fixMarkupRe, match => {
      if (match === '\n') {
        return options.useBR ? '<br>' : match;
      } else if (options.tabReplace) {
        return match.replace(/\t/g, options.tabReplace);
      }
      return match;
    });
  }
Post-processing of the highlighted markup:

  - replace TABs with something more useful
  - replace real line-breaks with '<br>' for non-pre containers

    @param {string} html
    @returns {string}