JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test">
</div>
<div id="output">
</div>

CSS

#test {
  visibility: hidden;
  opacity: 0;
}

JavaScript

// My way
$.fn.isVisible = function() {
    return ($(this).css('opacity') != '0' && $(this).css('visibility') !== 'hidden');
};

//original jQuery way
var test = $('#test').is(':visible');


$('#output').append('jQuery: ' + test 
													+'<br><br>' + 
											 'My way: '+ $('#test').isVisible());