if (text.includes("<script/( |<([^>]+)>)/></script>")) {
       alert("isset script");
} 
  
  const parseHTML = html => {
	const root = document.implementation.createHTMLDocument();
	root.body.innerHTML = html;
	return root.body.children[0];
}
const text = `
	<div>
		<h1>Text</h1>
		<script>
			console.log("!");
		</script>
	</div>
`;
if (parseHTML(text).querySelector('script')) {
	alert('isset script')
}