JSFiddle - React, Tailwind, and code Playground

HTML

<div id=div1>Div 1</div>

<div id=div2>Div 2</div>

CSS

#div1, #div2 {
    display: none;
}

JavaScript

$("#div1, #div2").fadeIn('500').promise().done(function()
{
    console.log('Test');
});