```typescript
/** The text, cut to limit characters with an ellipsis when it is longer. */
export function truncate(text: string, limit: number): string {
  if (typeof limit !== 'number' || limit < 3) {
    throw new Error('Limit must be an integer of at least 3.');
  }

  if (text.length <= limit) {
    return text;
  }

  const ellipsis = '...';
  return text.slice(0, limit - ellipsis.length) + ellipsis;
}
```