JSFiddle - React, Tailwind, and code Playground

HTML

<!--[if IE 8]><script>
    document.getElementsByClassName = 
    Element.prototype.getElementsByClassName = function(class_names) {
        // Turn input in a string, prefix space for later space-dot substitution
        class_names = (' ' + class_names)
            // Escape special characters
            .replace(/[~!@$%^&*()_+\-=,./';:"?><[\]{}|`#]/g, '\\$&')
            // Normalize whitespace, right-trim
            .replace(/\s*(\s|$)/g, '$1')
            // Replace spaces with dots for querySelectorAll
            .replace(/\s/g, '.');
        return this.querySelectorAll(class_names);
    };
    </script><![endif]-->
<div class="foo"></div>

JavaScript

document.getElementsByClassName('foo')[0].innerHTML = 'Test';