Spotify API models.SEARCHTYPE.SUGGESTION not working - api

Question

As the user types an artist name to search we want to display a drop-down list of suggestions based on what the user has typed so far.
For example, if the user has so far typed "Bob Dy" we would like to list "Bob Dylan","Bob Dylan & The Band", and "Willie Nelson;Bob Dylan" just like the standard Spotify Radio App does.
We are trying to use the Search API call to retrieve the list of artists to display. I assume we want to use the models.SEARCHTYPE.SUGGESTION option however when using that option we always get an empty list. The models.SEARCHTYPE.NORMAL option does return a list when there is an exact match such as in the case of entering "Bob" or "Bob Dylan" but not "Bob Dy".
Could you please tell us what we are doing wrong?
The documentation we are using is:
http://developer.spotify.com/download/spotify-apps-api/reference/833e3a06d6.html
Here is the code we are using:
var search = new models.Search('artist:"Bob Dy"');
search.localResults = models.LOCALSEARCHRESULTS.IGNORE;
search.searchArtists = true;
search.searchAlbums = false;
search.searchTracks = false;
search.searchPlaylists = false;
search.pageSize = 10;
search.searchType = models.SEARCHTYPE.SUGGESTION;
//search.searchType = models.SEARCHTYPE.NORMAL;
search.observe(models.EVENT.CHANGE, function() {
console.log('[models.EVENT.CHANGE observe]', search.artists);
});

Answer 1

Seems like the normal search input in Spotify doesn't support auto suggest for prefixed searches like "artist:Bob Dy". The code below works for me though.
var search = new models.Search('Bob Dy', {
'localResults' : models.LOCALSEARCHRESULTS.IGNORE,
'searchArtists' : true,
'searchAlbums' : false,
'searchTracks' : false,
'searchPlaylists' : false,
'pageSize' : 10,
'searchType' : models.SEARCHTYPE.SUGGESTION
});
search.observe(models.EVENT.CHANGE, function() {
search.artists.forEach(function(artist) {
console.log('[models.EVENT.CHANGE observe] - Found artist %s',
artist.name);
});
});
// Do the search, nothing will be fetched
// if this row is not executed.
search.appendNext();