pentaho/pentaho-kettle · error · KettleValueException

Script.Log.JavascriptError

Script.Log.JavascriptError

Error message

Script.Log.JavascriptError

What it means

Thrown in Script.addValues when the main transform script's evaluation throws a javax.script.ScriptException. After the scope is prepared, data.script.eval(data.scope) runs the user's JavaScript; any error raised inside the script (runtime error, thrown JS exception, undefined function call) surfaces as this KettleValueException. This is the standard failure path for buggy transform scripts.

Solutions

1. Read the wrapped ScriptException's line number/message to find the failing script line.
2. Add null/undefined checks around field access in the script.
3. Guard row-dependent logic with conditionals so rows missing fields don't crash the run.
4. Use the step's Test script feature with sample data reproducing the failing row.

Example fix

// before
var v = strField.toUpperCase();
// after
var v = (strField != null) ? strField.toUpperCase() : null;

// defensive script skeleton to run before trusting rows:
// if (typeof someField == "undefined" || someField == null) { someField = defaultValue; }

function isDefined(v) { return typeof v !== "undefined" && v !== null; }

try {
  step.processRow();
} catch (KettleValueException e) {
  if (e.getMessage().contains("JavascriptError") || e.getCause() instanceof ScriptException) {
    logError("Script runtime error: " + e.getCause().getMessage());
    putError(...); // route row to error handling instead of failing
  } else { throw e; }
}

When it happens

Trigger: addValues (called from processRow): data.script.eval(data.scope) throws a ScriptException — e.g. calling an undefined function, accessing a property of an undefined variable, or the script explicitly throwing — on any row being processed.

Common situations: Scripts referencing fields not present on some rows (null handling mistakes); calling functions that don't exist in this engine (Rhino vs Nashorn differences); division by zero or type coercion errors on dirty data; using Java imports unavailable in the sandbox.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Could not convert the given String :
• e.toString()
• Please provide a valid Char to the fillString
• Script.Log.CouldNotAddDefaultConstants
• Script.Log.CouldNotAttachAdditionalScripts

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/8a47e6a12940681b. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/script/Script.java:386

            break;
          case ERROR_TRANSFORMATION:
            if ( data.cx != null ) {
              // Context.exit(); TODO AKRETION not sure
              setErrors( 1 );
            }
            stopAll();
            bRC = false;
            break;
          default:
            break;
        }

        // TODO: kick this "ERROR handling" junk out now that we have
        // solid error handling in place.
        //
      }
    } catch ( ScriptException e ) {
      throw new KettleValueException( BaseMessages.getString( PKG, "Script.Log.JavascriptError" ), e );
    }
    return bRC;
  }

  public Object getValueFromJScript( Object result, int i ) throws KettleValueException {
    String fieldName = meta.getFieldname()[ i ];
    if ( !Utils.isEmpty( fieldName ) ) {
      // res.setName(meta.getRename()[i]);
      // res.setType(meta.getType()[i]);

      try {
        return ( result == null ) ? null
          : JavaScriptUtils.convertFromJs( result, meta.getType()[ i ], fieldName );
      } catch ( Exception e ) {
        throw new KettleValueException( BaseMessages.getString( PKG, "Script.Log.JavascriptError" ), e );
      }
    } else {
      throw new KettleValueException( "No name was specified for result value #" + ( i + 1 ) );

View on GitHub (pinned to f3058517a1)