cube-js/cube · error · Error

List of references and a function are expected in form…

Error message

List of references and a function are expected in form: dynRef('ref', (r) => (...))

What it means

The dynRef extension helper creates a DynamicReference and requires at least two arguments: one or more reference names plus a generating function. It throws when fewer than two arguments are supplied, because there would be no function to evaluate the reference with.

Solutions

1. Call dynRef with at least one reference string followed by a function: dynRef('ref', (r) => ...)
2. If args are built dynamically, append the generator function as the last element before spreading
3. Check for accidental typos like dynRef('ref') missing the callback

Example fix

// before
dynRef((r) => r('users.count'));
// after
dynRef('users', (r) => r('users.count'));

const canCallDynRef = (...args) => args.length >= 2;

const canCallDynRef = (...args) => args.length >= 2 && args.length - 1 >= 1;

try {
  const ref = reflection.dynRef(...dynRefArgs);
} catch (e) {
  if (e.message.includes('dynRef')) {
    console.error("Call dynRef('ref', (r) => (...)) with at least one reference and a function");
  }
  throw e;
}

When it happens

Trigger: Calling dynRef() with no arguments, a single argument, or spreading an empty/one-element array into dynRef.

Common situations: Building dynRef calls programmatically and spreading an array without the function; misreading the signature as dynRef(fn) instead of dynRef('ref', fn); refactors that dropped the reference name argument.

Understand the failure class

Background: "must be a positive integer", "cannot be empty", "invalid argument": how invalid-argument errors work across open-source libraries — this error's family across 33 libraries.

Related errors

• Last argument should be a function
• resultIndex is required
• steps are not defined
• time.sql is not defined
• userId.sql is not defined

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/441debde84d56ea6. Report an issue: GitHub.

Appendix: source

Thrown at packages/cubejs-schema-compiler/src/extensions/Reflection.ts:8

import R from 'ramda';
import { DynamicReference } from '../compiler/DynamicReference';
import { AbstractExtension } from './extension.abstract';

export class Reflection extends AbstractExtension {
  public dynRef = (...args) => {
    if (args.length < 2) {
      throw new Error('List of references and a function are expected in form: dynRef(\'ref\', (r) => (...))');
    }

    const references = R.dropLast(1, args);
    const fn = args[args.length - 1];

    if (typeof fn !== 'function') {
      throw new Error('Last argument should be a function');
    }

    return new DynamicReference(references, fn);
  };
}

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