Get list of files in directory matching mask, excluding directories, with Bluebird

gistfile1.js

return Promise.promisify(fs.readdir)(config.path).filter(function (fileName) {
    return config.mask.test(fileName);
}).map(function (fileName) {
    var fullPath = path.join(config.path, fileName);
    return Promise.promisify(fs.stat)(fullPath).tap(function (stat) {
        stat.fullPath = fullPath;
        stat.fileName = fileName;
    });
}).filter(function (stat) {
    return stat.isFile();
}).map(function (stat) {
    return stat.fullPath;
});

fs.readdir(function (err, res) {
  if (err) { throw err; }
  res = res.filter(function (fileName) {
    return config.mask.test(fileName);
  });
  var stats = [], count = res.length;
  res.forEach(function (fileName, idx) {
    var fullPath = path.join(config.path, fileName);
    fs.stat(fullPath, function (err, res) {
      if (err) { throw err; }
      stats[idx] = res;
      count--;
      if (count === 0) {
        res = res.filter(function (fileName, idx) {
          return stats[idx].isFile();
        });
      }
    });
  });
});