src/language-html/utils/index.js/getLeadingAndTrailingHtmlWhitespace
const getLeadingAndTrailingHtmlWhitespace = (string) => {
  const [, leadingWhitespace, text, trailingWhitespace] = string.match(
    /^([\t\n\f\r ]*)(.*?)([\t\n\f\r ]*)$/s
  );
  return {
    leadingWhitespace,
    trailingWhitespace,
    text,
  };
};