JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li>item 1</li>
  <li>item 2</li>
  <span class="test">item 3</li>
  <li>item 4</li>
  <li>item 5</li>
</ul>

CSS

.some-class {
    background : green;
}

JavaScript

$('span.test:contains("item 3")').addClass('some-class');