code: func fileExt(path string) string {
  	if strings.HasSuffix(path, ".tf") {
  		return ".tf"
  	} else if strings.HasSuffix(path, ".tf.json") {
  		return ".tf.json"
  	} else {
  		return ""
  	}
  }
docs: // fileExt returns the Terraform configuration extension of the given
  // path, or a blank string if it is not a recognized extension.