mongodb/node-mongodb-native · error · MongoParseError

can only be a positive int value, got

Error message

${name} can only be a positive int value, got: ${value}

What it means

Unsigned-int options (srvMaxHosts and similar) accept any integer but reject negatives. getUIntFromOptions calls getIntFromOptions then checks for <0 and throws, including the original value in the message.

Solutions

1. Use 0 (or omit the option) to disable srvMaxHosts.
2. Pass a positive integer to cap the number of hosts.

Example fix

// before
new MongoClient('mongodb+srv://h/db?srvMaxHosts=-1');
// after
new MongoClient('mongodb+srv://h/db?srvMaxHosts=0');

function assertUIntOption(name: string, value: unknown) {
  assertIntOption(name, value);
  if (Number(value) < 0) throw new Error(`${name} must be >= 0, got: ${value}`);
}

When it happens

Trigger: Passing a negative integer to an unsigned option, e.g. 'srvMaxHosts=-1' in the URI or srvMaxHosts: -1 in options.

Common situations: Using -1 as a 'disable' sentinel the way some other libraries do, or arithmetic that underflows.

Related errors

• Expected to be stringified int value, got
• All values of tls/ssl must be the same.
• Auth mechanism property ALLOWED_HOSTS is not allowed in the…
• authMechanism requires an authSource of '$external
• Cannot combine replicaSet option with srvMaxHosts

AI-assisted analysis of mongodb/node-mongodb-native@dce7939f86 (2026-08-11). Data as JSON: /api/errors/2217379d9eff4670. Report an issue: GitHub.

Appendix: source

Thrown at src/connection_string.ts:199

    case 'false':
      return false;
    default:
      throw new MongoParseError(`${name} must be either "true" or "false"`);
  }
}

function getIntFromOptions(name: string, value: unknown): number {
  const parsedInt = parseInteger(value);
  if (parsedInt != null) {
    return parsedInt;
  }
  throw new MongoParseError(`Expected ${name} to be stringified int value, got: ${value}`);
}

function getUIntFromOptions(name: string, value: unknown): number {
  const parsedValue = getIntFromOptions(name, value);
  if (parsedValue < 0) {
    throw new MongoParseError(`${name} can only be a positive int value, got: ${value}`);
  }
  return parsedValue;
}

function* entriesFromString(value: string): Generator<[string, string]> {
  if (value === '') {
    return;
  }
  const keyValuePairs = value.split(',');
  for (const keyValue of keyValuePairs) {
    const [key, value] = keyValue.split(/:(.*)/);
    if (value == null) {
      throw new MongoParseError('Cannot have undefined values in key value pairs');
    }

    yield [key, value];
  }
}

View on GitHub (pinned to dce7939f86)