```ts
/**
 * The text, cut to limit characters with an ellipsis when it is longer.
 */
export function truncate(text: string, limit: number): string {
  if (!Number.isInteger(limit) || limit < 3) {
    throw Error("limit must be a three-digit integer");
  }

  const length = text.length;

  if (length <= limit) {
    return text;
  } else {
    return `${text.slice(0, limit - 4)}...`;
  }
}
```