The truncate function can be redefined to ensure that one character is subtracted from the limit rather than removed. The fixed `truncate` function is provided below:

```ts
/** The text, cut to exactly limit characters with an ellipsis when it is longer. */
export function truncate(text: string, limit: number): string {
  if (limit < 3) {
    throw new Error('Limit must be at least 3');
  }
  // return original text if its length isn't greater than the limit
  if (text.length <= limit) {
    return text;
  }
  // else truncate it and append "..."
  else{
      let truncatedText = text.slice(0, limit - 3); // subtract 3 for ellipsis characters
      truncatedText += '...';
     return truncatedText;   
  }
}
```