pentaho/pentaho-kettle · error · RuntimeException

The function call LuhnCheck requires 1 argument.

Error message

The function call LuhnCheck requires 1 argument.

What it means

Arity guard in ScriptAddedFunctions.LuhnCheck: the function was invoked from a script with an ArgList whose length is not 1, so the Luhn checksum cannot be computed. The input at fault is the script's argument list; the intended single string argument must be numeric-parsable, otherwise the function silently returns false.

Solutions

1. Call LuhnCheck with exactly one argument containing the full number
2. Pre-compute/strip any extra values in JS before the call
3. Use a JS wrapper that enforces arity

Example fix

// before
var ok = LuhnCheck(cardNum, 7);
// after
var ok = LuhnCheck(cardNum);

// JS in Script step
if (arguments.length !== 1) {
  throw new Error('LuhnCheck expects exactly one argument');
}
var ok = LuhnCheck(String(cardNum));

// JS
function isSingleArg(args) {
  return args.length === 1;
}

try {
  var ok = LuhnCheck(cardNum);
} catch (e) {
  Logger.logError('LuhnCheck failed: ' + e.message);
  ok = false;
}

When it happens

Trigger: Calling LuhnCheck() with zero args or with multiple args (e.g. LuhnCheck(num, expectedCheckDigit)) inside a Script step.

Common situations: Assuming the check digit can be passed separately; translating pseudocode that splits the number into parts.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• The function call abs requires 1 argument.
• The function call appendToFile requires arguments.
• The function call ceil requires 1 argument.
• The function call getDigitsOnly requires 1 argument.
• The function call getFiscalDate requires 2 arguments.

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/54e4faa8085f4706. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/script/ScriptAddedFunctions.java:154

            } else {
              addend = digit;
            }
            sum += addend;
            timesTwo = !timesTwo;
          }

          int modulus = sum % 10;
          if ( modulus == 0 ) {
            returnCode = true;
          }
        } catch ( Exception e ) {
          // No Need to throw exception
          // This means that input can not be parsed to Integer
        }

      }
    } else {
      throw new RuntimeException( "The function call LuhnCheck requires 1 argument." );

    }
    return returnCode;
  }

  public static int indexOf( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {

    int returnIndex = -1;

    if ( ArgList.length == 2 || ArgList.length == 3 ) {
      if ( !isNull( ArgList ) && !isUndefined( ArgList ) ) {
        String string = (String) ArgList[0];
        String subString = (String) ArgList[1];

        int fromIndex = 0;
        if ( ArgList.length == 3 ) {
          fromIndex = (int) Math.round( (Double) ArgList[2] );

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