code: func isPathUnder(base, path string) (bool, error) {
  	absBase, err := filepath.Abs(base)
  	if err != nil {
  		return false, err
  	}
  	absPath, err := filepath.Abs(path)
  	if err != nil {
  		return false, err
  	}
  
  	relPath, err := filepath.Rel(absBase, absPath)
  	if err != nil {
  		return false, err
  	}
  
  	// if path is below base, the relative path
  	// from base to path will not start with `../`
  	return !strings.HasPrefix(relPath, ".."), nil
  }
docs: // isPathUnder determines if path is under base