JSFiddle - React, Tailwind, and code Playground

HTML

<form id="post-status-form" onsubmit="return test(this,event);" method="post">
   <textarea id="composer-textarea" class="grow" name="composer-textarea"></textarea>
   <input type="hidden" value="1" name="targetid" id="targetid" />
</form>

JavaScript

$('composer-textarea').addEvent('keydown', function(e) {
    if(e.key == 'enter') {
        e.stop();
        $('post-status-form').submit();
    }
});