code: function findPath(path, directories) {
    var cwd = directories[0];
  
    if (!cwd) {
      return null;
    }
  
    return findup(path, {cwd: cwd}) || findPath(path, slice.call(directories, 1));
  }
docs: Find the requested path inside a list of candidate directories.
  
  @param  {String} path        Path to locate.
  @param  {Array}  directories Array of directories.
  @return {String}             Located path, or null if not found.