JSFiddle - React, Tailwind, and code Playground

HTML

<p>text.. <span>hi</span><a>bye</a> more text..</p>

JavaScript

(function () {
    var p = document.querySelector("p");
    p.textContent = [].reduce.call(p.childNodes, function (p, c) {
        c.nodeType === 3 && p.push(c.data);
        return p;
    }, []).join("");
})();