Correct a broken HTML file or a HTML String

Example 1 : With DOMDocument: (Fast (0.0002 sec) but can have php warning)

$datas = '<div><p>Hello';

$doc = new DOMDocument();

$doc->loadHTML('<?xml encoding="UTF-8">' . $datas);

$datas_new = $doc->saveHTML($doc->documentElement->firstChild->firstChild);

Example 2  With Drupal 8 Utility: (Slow (0.01 sec) but correct way)

$text_new = \Drupal\Component\Utility\Html::normalize($text);