MP3 Player for simple http server with file listing

player.html

<script src="https://code.jquery.com/jquery-2.2.3.js" integrity="sha256-laXWtGydpwqJ8JA+X9x2miwmaiKhn8tVmOVEigRNtP4=" crossorigin="anonymous"></script>
<script>
$(function() {
  var audio;
  var playlist;
  var tracks;
  var current;
  fetch('./').then((res) => {
    res.text().then((text) => {
      let tmp = $('<div />').html(text)
      let links = tmp.find("a[href$='.mp3']")
      $('#playlist').html(links)
      init()
      return tmp
    })
  })
  function init(){
    current = 0;
    audio = $('audio');
    playlist = $('#playlist');
    tracks = playlist.find('a');
    len = tracks.length - 1;
    audio[0].play();
    playlist.find('a').click(function(e) {
      e.preventDefault();
      link = $(this);
      current = link.index();
      run(link, audio[0]);
    });
    audio[0].addEventListener('ended', function(e){
      current++;
      if(current == len){
        current = 0;
        link = playlist.find('a')[0];
      }else{
        link = playlist.find('a')[current];    
      }
      run($(link),audio[0]);
    });
  }
  function run(link, player){
    player.src = link.attr('href');
    audio[0].load();
    audio[0].play();
  }
})
</script>
<style>
#playlist a { display: block }
</style>
<audio id="audio" preload="auto" tabindex="0" controls="" type="audio/mpeg">
</audio>
<div id="playlist">
</div>