code: function isSrcSubdir (src, dest) {
    try {
      return fs.statSync(src).isDirectory() &&
             src !== dest &&
             dest.indexOf(src) > -1 &&
             dest.split(path.dirname(src) + path.sep)[1].split(path.sep)[0] === path.basename(src)
    } catch (e) {
      return false
    }
  }
docs: return true if dest is a subdir of src, otherwise false. extract dest base dir and check if that is the same as src basename