Microservice to fetch data about the last song I played from last.fm

microservice_last-song.js

module.exports = function lastPlay(hook) {
  var req = require("request-promise");
  var url = "http://ws.audioscrobbler.com/2.0/?method=user.getRecentTracks&user=himynameisdave9&api_key="+hook.env.lastsong_lastfm_key+"&format=json";
  var stringify = function(data) {
    return JSON.stringify(data, true, 2);
  };
  var blackList = ["Hello Internet", "This American Life", "Myke Hurley and CGP Grey"]; // items that we don't want showing up
  var isValidArtist = function (artist) {
    var validity = blackList.filter(function(dontAdd){
      return artist.toLowerCase().indexOf(dontAdd.toLowerCase()) >= 0;
    });
    return validity.length === 0;
  };

  req(url)
    .then(function(data){
      var lastPlayed = JSON.parse(data).recenttracks.track.filter(function(track, i){
        if ( track.artist["#text"] ){
          return isValidArtist(track.artist["#text"])
        }
        return false;
      })[0];// there is normally an array bc each track may have different "versions"... we're always gonna use the first one in the array though, hence [0]
      hook.res.end(stringify({
          name:       lastPlayed.name || "Unknown Track",
          artist:     lastPlayed.artist["#text"] || "Unknown Artist",
          album:      lastPlayed.album["#text"] || "Unknown Album",
          url:        lastPlayed.url || "http://www.last.fm/user/himynameisdave9",
          image:      lastPlayed.image.slice(-1).pop()["#text"] || "http://i.imgur.com/OYU5axd.png",
          nowplaying: lastPlayed["@attr"] ? true : false
        })
      );
    })
    .catch(function(e){
      hook.res.end(stringify({
        message: "Error fetching lastfm data!",
        error: e
      }))
    });
};