JSFiddle - React, Tailwind, and code Playground

HTML

<span class="foo">
   <span class="bar">+</span>
   lorem ispum lorem ispumlorem ispumlorem ispum
</span>

JavaScript

$('.foo').contents().filter(function() {
        return this.nodeType == 3 && $.trim(this.textContent) != '';
    }).wrap('<span class="foobar" />');