mongodb/node-mongodb-native · error · MongoParseError

Expected to be stringified int value, got

Error message

Expected ${name} to be stringified int value, got: ${value}

What it means

Integer URI options (e.g. srvMaxHosts, serverSelectionTimeoutMS, connectTimeoutMS) must parse as an integer. getIntFromOptions calls parseInteger; if it returns null (non-numeric, empty, or fractional), this error is thrown with the offending value.

Solutions

1. Provide a bare integer number of milliseconds (or the option's documented unit) with no suffix.
2. Double-check the option name's expected unit in the driver docs.

Example fix

// before
new MongoClient('mongodb://h/db?connectTimeoutMS=30s');
// after
new MongoClient('mongodb://h/db?connectTimeoutMS=30000');

function assertIntOption(name: string, value: unknown) {
  if (!/^[-+]?\d+$/.test(String(value))) {
    throw new Error(`${name} must be an integer, got: ${value}`);
  }
}

function isStringifiedInt(v: unknown): v is string | number {
  return /^[-+]?\d+$/.test(String(v));
}

When it happens

Trigger: Supplying a non-integer value to an int option in the URI, e.g. 'srvMaxHosts=three', 'connectTimeoutMS=30s', or 'serverSelectionTimeoutMS=12.5'.

Common situations: Unit suffixes ('30s', '5ms') that the driver does not parse, locale-specific formatting, or copy-pasting human-readable durations from docs.

Related errors

• Cannot have undefined values in key value pairs
• can only be a positive int value, got
• must be either "true" or "false
• All values of tls/ssl must be the same.
• Auth mechanism property ALLOWED_HOSTS is not allowed in the…

AI-assisted analysis of mongodb/node-mongodb-native@dce7939f86 (2026-08-11). Data as JSON: /api/errors/b65a76ca667f2843. Report an issue: GitHub.

Appendix: source

Thrown at src/connection_string.ts:193

}
function getBoolean(name: string, value: unknown): boolean {
  if (typeof value === 'boolean') return value;
  switch (value) {
    case 'true':
      return true;
    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) {

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