index.html

<button id=submit>Submit</button>
<div id=log style='white-space: pre'></div>
<script>
const button = document.getElementById('submit');
button.addEventListener('mousedown', () => {
  print('1. down');
  Promise.resolve().then(() => print('2. down task ends'));
});
button.addEventListener('mouseup', () => {
  print('3. up');
  Promise.resolve().then(() => print('4. up task ends'));
});
button.addEventListener('click', () => {
  print('5. click');
  Promise.resolve().then(() => print('6. click task ends'));
});

const text = [];
function print(line) {
  text.push(line);
  document.getElementById('log').textContent = text.join('\n');
}
</script>