JSFiddle - React, Tailwind, and code Playground

HTML

<form id="search-form" name="search-form" onsubmit="return search()">
         <input type="search" id="query" class="search-field" value="<?php echo $searchQuery;?>">
         <input type="submit" name="search-btn" id="search-btn" value="">
        </form>

JavaScript

function ready( fn ) {
        if ( document.attachEvent ? document.readyState === 'complete' : document.readyState !== 'loading' ) {
          fn();
        } else {
          document.addEventListener( 'DOMContentLoaded', fn );
        }
    }

    ready( function() {
        if ( document.getElementById( 'query' ).value != '' ) {
            document.getElementById( 'search-form' ).submit();
        }
    });