Function needsRetryableWriteLabel

src/error.ts:1397–1444

(
  error: Error,
  maxWireVersion: number,
  serverType: ServerType
)

const RETRYABLE_WRITE_ERROR_CODES = RETRYABLE_READ_ERROR_CODES;

export function needsRetryableWriteLabel(
  error: Error,
  maxWireVersion: number,
  serverType: ServerType
): boolean {
  // pre-4.4 server, then the driver adds an error label for every valid case
  // execute operation will only inspect the label, code/message logic is handled here
  if (error instanceof MongoNetworkError) {
    return true;
  }

  if (error instanceof MongoError) {
    if (
      (maxWireVersion >= 9 || isRetryableWriteError(error)) &&
      !error.hasErrorLabel(MongoErrorLabel.HandshakeError)
    ) {
      // If we already have the error label no need to add it again. 4.4+ servers add the label.
      // In the case where we have a handshake error, need to fall down to the logic checking
      // the codes.
      return false;
    }
  }

  if (error instanceof MongoWriteConcernError) {
    if (serverType === 'Mongos' && maxWireVersion < 9) {
      // use original top-level code from server response
      return RETRYABLE_WRITE_ERROR_CODES.has(error.result.code ?? 0);
    }
    const code = error.result.writeConcernError.code ?? Number(error.code);
    return RETRYABLE_WRITE_ERROR_CODES.has(Number.isNaN(code) ? 0 : code);
  }

  if (error instanceof MongoError) {
    return RETRYABLE_WRITE_ERROR_CODES.has(Number(error.code));
  }

  const isNotWritablePrimaryError = LEGACY_NOT_WRITABLE_PRIMARY_ERROR_MESSAGE.test(error.message);
  if (isNotWritablePrimaryError) {
    return true;
  }

  const isNodeIsRecoveringError = NODE_IS_RECOVERING_ERROR_MESSAGE.test(error.message);
  if (isNodeIsRecoveringError) {
    return true;
  }

  return false;
}

export function isRetryableWriteError(error: MongoError): boolean {
  return (