JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test"></div>
<div id="test"></div>
<div id="test"></div>
<div id="test"></div>
<div id="not-a-test">

JavaScript

(function () {  
    var found = false;  
    $('[id]').each(function () {  
        var ids = $('[id=' + this.id + ']');  
        if (ids.length > 1 && ids[0] === this) {  
            console.warn('ID used more than once: ' + this.id, ids);  
            found = true;  
        }  
    });  
    if (!found) {  
        console.log('No duplicate IDs found');  
    }  
})();