TanStack/table · info

${message}

Error message

${message}

What it means

This is the internal `warn(message)` helper in rowAggregationFeature.utils.ts: it prefixes `console.warn` with the given message, but only when `process.env.NODE_ENV === 'development'`. It is the shared warning sink for all row-aggregation misconfigurations (unregistered/duplicate aggregation fns, missing stable ids). Seeing `${message}` means some aggregation option did not fully resolve, and the actual text comes from whichever caller invoked `warn`.

Source

Thrown at packages/table-core/src/features/row-aggregation/rowAggregationFeature.utils.ts:52

function isAggregationFnDef(value: unknown): value is AggregationFnDef {
  return !!value && typeof value === 'object' && 'aggregate' in value
}

function isAggregationFnDescriptor(
  value: unknown,
): value is AggregationFnDescriptor<any, any> {
  return (
    !!value &&
    typeof value === 'object' &&
    'id' in value &&
    'aggregationFn' in value
  )
}

function warn(message: string) {
  if (process.env.NODE_ENV === 'development') {
    console.warn(message)
  }
}

function resolveMaxAggregationDepth(maxDepth: number | undefined) {
  return maxDepth === undefined || Number.isNaN(maxDepth)
    ? 0
    : Math.max(0, Math.floor(maxDepth))
}

function collectNormalizedAggregationRow<
  TFeatures extends TableFeatures,
  TData extends RowData,
>(
  row: Row<TFeatures, TData>,
  depth: number,
  maxDepth: number,
  seen: Set<string>,
  result: Array<Row<TFeatures, TData>>,

View on GitHub (pinned to d01c01bedb)

Solutions

1. Read the full warning text — it names the column id and the specific problem (not registered, duplicated, or needs a stable id).
2. If it says 'is not registered', add the referenced key to the `aggregationFns` registry or pass the function object directly.
3. If it says 'needs a stable id', use a string ref or an object descriptor `{ id, aggregationFn }` in the array option.
4. If it says 'duplicated', give each entry in the aggregationFn array a unique id.
5. Verify NODE_ENV: this warning only appears in development, so do not rely on it in production builds.

// Validate aggregation config before creating the table
function validateAggregationOption(option: unknown, fns: Record<string, unknown>) {
  if (option == null) return
  if (Array.isArray(option)) {
    option.forEach((item, i) => {
      const id = typeof item === 'string' ? item : (item as any)?.id
      if (id === undefined) throw new Error(`aggregationFn[${i}] needs an id`)
    })
  } else if (typeof option === 'string' && option !== 'auto' && !(option in fns)) {
    throw new Error(`aggregationFn '${option}' not registered`)
  }
}

function hasStableId(
  item: unknown,
): item is { id: string; aggregationFn: unknown } {
  return (
    !!item &&
    typeof item === 'object' &&
    typeof (item as any).id === 'string'
  )
}

try {
  const entries = column.getAggregationFns()
  const broken = entries.filter((e) => e.aggregationFn === undefined)
  if (broken.length) console.warn(`${broken.length} aggregation entries unresolved`)
} catch (e) {
  console.error('aggregation resolution failed', e)
}

When it happens

Trigger: Any code path in the aggregation feature calling `warn(...)` during dev-mode rendering: resolving a column's `aggregationFn` option (string lookup failing), auto-detecting an aggregation for numeric/Date columns, or iterating an array-valued `aggregationFn` option with missing or duplicate ids. All run via `column_getAggregationFns` / `column_getAutoAggregationFn` / `resolveAggregationFn` when the aggregation row model or `getAggregationValue` is evaluated.

Common situations: Development builds only (warning stripped in production, so teams miss it until QA on staging); first render of a grouped/aggregated table; adding a new aggregated column with a hand-written descriptor missing `id`.

Related errors

• aggregationFn '${String(ref)}' for column '${column.id}' is
• aggregationFn at index ${i} for column '${column.id}' needs
• aggregationFn id '${id}' for column '${column.id}' is duplic
• globalFilterFn '${String(globalFilterFn)}' is not registered
• [table-worker] ${message}

AI-assisted analysis of TanStack/table@d01c01bedb (2026-08-28). Data as JSON: /api/errors/c934746b35aa155c. Report an issue: GitHub.