stylelint-bundle-worker.js
function matcher(pattern, opts) {
  // pattern is a function
  if (typeof pattern === 'function') {
    return pattern;
  }
  // pattern is a regex
  if (pattern instanceof RegExp) {
    return function(fp) {
      return pattern.test(fp);
    };
  }

  if (typeof pattern !== 'string') {
    throw new TypeError(msg('matcher', 'pattern', 'a string, regex, or function'));
  }

  // strings, all the way down...
  pattern = utils.unixify(pattern, opts);

  // pattern is a non-glob string
  if (!utils.isGlob(pattern)) {
    return utils.matchPath(pattern, opts);
  }
  // pattern is a glob string
  var re = makeRe(pattern, opts);

  // `matchBase` is defined
  if (opts && opts.matchBase) {
    return utils.hasFilename(re, opts);
  }
  // `matchBase` is not defined
  return function(fp) {
    fp = utils.unixify(fp, opts);
    return re.test(fp);
  };
}
function matcher(pattern, opts) {
  // pattern is a function
  if (typeof pattern === 'function') {
    return pattern;
  }
  // pattern is a regex
  if (pattern instanceof RegExp) {
    return function(fp) {
      return pattern.test(fp);
    };
  }

  if (typeof pattern !== 'string') {
    throw new TypeError(msg('matcher', 'pattern', 'a string, regex, or function'));
  }

  // strings, all the way down...
  pattern = utils.unixify(pattern, opts);

  // pattern is a non-glob string
  if (!utils.isGlob(pattern)) {
    return utils.matchPath(pattern, opts);
  }
  // pattern is a glob string
  var re = makeRe(pattern, opts);

  // `matchBase` is defined
  if (opts && opts.matchBase) {
    return utils.hasFilename(re, opts);
  }
  // `matchBase` is not defined
  return function(fp) {
    fp = utils.unixify(fp, opts);
    return re.test(fp);
  };
}
Return a function for matching based on the
given `pattern` and `options`.

@param  {String} `pattern`
@param  {Object} `options`
@return {Function}