JSFiddle - React, Tailwind, and code Playground

HTML

<input id="input" type="file"/><br/>

<button id="button">This be a button</button>

<div id="target">

</div>

JavaScript

(function() {
  const longtime = 500;
  const target = document.getElementById('target');
 	const input = document.getElementById('input');
	const button = document.getElementById('button');
  var timedown = 0;
  button.onmousedown = () => {
  	timedown = new Date().getTime();
  };
  button.onmouseup = () => {
  	let timeup = new Date().getTime();
    let insert = document.createElement('div');
    if( (timeup - timedown) < longtime ) {
      insert.appendChild(document.createTextNode('Short!'));
    } else {
    	insert.appendChild(document.createTextNode('Long!'));
      input.click();
    }
    target.appendChild(insert);
  }
})()