JSFiddle - React, Tailwind, and code Playground

HTML

<textarea>test test
test test</textarea>
<textarea>test test

    test test

test test test</textarea>

JavaScript

$('textarea').each(function(){
        var height = $('<div style="display:none; white-space:pre" id="my-hidden-div"></div>').html($(this).val()).appendTo('body').height();
        $(this).css('height',height + 'px');
        $('#my-hidden-div').remove();
    });