cube-js/cube · error · Error

List of references and a function are expected in form: dynR

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.

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);
  };
}

View on GitHub (pinned to 7d981676b3)

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
• userId.sql is not defined
• time.sql is not defined
• steps are not defined

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