```ts
/**
 * 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 a non-negative integer of at least 3");
  }
  if (text.length > limit) {
    return text.slice(0, limit - 4) + "...";
  }
  return text;
}
```