Fix getDiscography() for one-album / track artists

lib/index.js

@@ -108,7 +108,9 @@ async function getTrackInfo(trackUrl, options = {}) {
 }
 
 async function getDiscography(artistOrLabelUrl, options = {}) {
+    const imageConstants = await _getImageConstants();
     const opts = {
+        imageBaseUrl: imageConstants.baseUrl,
         artistOrLabelUrl,
         imageFormat: await _parseImageFormatArg(options.imageFormat)
     };

lib/parser.js

@@ -248,9 +248,45 @@ function parseTrackInfo(html, opts) {
 
 function parseDiscography(html, opts) {
     const $ = cheerio.load(html);
+
+    // One-album / one-track artists don't have a discography page.
+    // The page for the album or track will be loaded instead.
+    // Check if this is the case and handle accordingly
+    const currentAlbumOrTrack = $('script[type="application/ld+json"]');
+    let isOneTrack = false,
+        isOneAlbum = false;
+    if (currentAlbumOrTrack.length) {
+        currentAlbumOrTrackData = JSON.parse(currentAlbumOrTrack.html());
+        if (typeof currentAlbumOrTrackData === 'object') {
+            // Check if there is a 'discography' element and, if there is, whether
+            // it is hidden or has only one track / album child
+            const discographyEl = $('#discography');
+            if (discographyEl.length === 0 || discographyEl.css('display') === 'none' || discographyEl.find('li').length === 1) {
+                currentAlbumOrTrackUrl = utils.splitUrl(currentAlbumOrTrackData['@id']);
+                isOneTrack = currentAlbumOrTrackUrl.path.startsWith('/track/');
+                isOneAlbum = currentAlbumOrTrackUrl.path.startsWith('/album/');
+            }
+        }
+    }
+    if (isOneTrack || isOneAlbum) {
+        const newOpts = {
+            imageBaseUrl: opts.imageBaseUrl,
+            albumImageFormat: opts.imageFormat,
+            artistImageFormat: null,
+            includeRawData: false
+        };
+        let info = isOneTrack ? parseTrackInfo(html, newOpts) : parseAlbumInfo(html, newOpts);
+        return [{
+            url: info.url,
+            type: info.type,
+            name: info.name || '',
+            imageUrl: info.imageUrl || null,
+            artist: info.artist.name
+        }];
+    }
+
     const allLinks = $('a');
     const items = {};
-    const isLabel = $('a[href="/artists"]').length;
     const defaultArtistName = $('#band-name-location').find('.title').text();
     allLinks.each( (index, link) => {
         link = $(link);