proper alignment of filters

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/CatalogDatabase.kt

@@ -906,6 +906,10 @@ interface CatalogDao {
     groupingMode: String,
   ): List<ArtistSummaryEntity>
 
+  // 'song' only: an album the artist merely guests on (a Various Artists
+  // compilation carrying one of their tracks) is not one of their albums. Those
+  // tracks are already reachable through the detail page's "Appears On" section,
+  // which reads the 'appearance' half of the same index.
   @Query(
     """
       SELECT DISTINCT a.*
@@ -916,6 +920,7 @@ interface CatalogDao {
         AND i.revision = :revision
         AND i.grouping_mode = :groupingMode
         AND i.artist_key = :artistKey
+        AND i.relationship = 'song'
       ORDER BY a.latest_added_at DESC, a.name_sort_key, a.identity_key
       LIMIT :limit OFFSET :offset
     """,
@@ -936,6 +941,7 @@ interface CatalogDao {
       WHERE i.revision = :revision
         AND i.grouping_mode = :groupingMode
         AND i.artist_key = :artistKey
+        AND i.relationship = 'song'
     """,
   )
   suspend fun countArtistAlbums(

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/CatalogReadModelBuilder.kt

@@ -260,13 +260,20 @@ object CatalogReadModelBuilder {
         } else {
           canonicalArtistNames(track)
         }
+        val primaryKey = normalizeKey(primary)
         for (name in names) {
           val key = normalizeKey(name)
           if (key.isEmpty()) continue
+          val isPrimary = key == primaryKey
           val aggregate = aggregates.getOrPut(key) { Aggregate(name) }
           aggregate.trackCount += 1
-          if (key == normalizeKey(primary)) aggregate.primaryCount += 1
+          if (isPrimary) {
+            aggregate.primaryCount += 1
+            // Albums the artist only guests on are not their albums; counting
+            // them here credited a Various Artists compilation to every featured
+            // performer. Artwork stays ungated so those artists keep a mosaic.
             aggregate.albumKeys += row.identityKey
+          }
           val current = aggregate.artworkTrack
           if (track.artworkHash != null && (current == null || newerArtwork(track, current))) {
             aggregate.artworkTrack = track
@@ -277,7 +284,7 @@ object CatalogReadModelBuilder {
             groupingMode = mode,
             artistKey = key,
             trackId = track.id,
-            relationship = if (key == normalizeKey(primary)) "song" else "appearance",
+            relationship = if (isPrimary) "song" else "appearance",
           )
         }
       }

src/app/(tabs)/library/artist/[name].tsx

@@ -127,8 +127,14 @@ export default function ArtistScreen() {
   ]);
 
   const listItems = useMemo(
-    () => buildListItems(detail, songsPage.totalCount, appearancesPage.totalCount),
-    [appearancesPage.totalCount, detail, songsPage.totalCount]
+    () =>
+      buildListItems(
+        detail,
+        albumsPage.totalCount,
+        songsPage.totalCount,
+        appearancesPage.totalCount
+      ),
+    [albumsPage.totalCount, appearancesPage.totalCount, detail, songsPage.totalCount]
   );
 
   const playTrackListFrom = (
@@ -331,11 +337,13 @@ export default function ArtistScreen() {
         title={name}
         heroMeta={
           <View style={styles.stats}>
-            {(allPage.summary?.album_count ?? detail.albums.length) > 0 ? (
-              <StatChip
-                icon="albums-outline"
-                label={formatCount(allPage.summary?.album_count ?? detail.albums.length, 'album')}
-              />
+            {/*
+              The album page's own count, not summary.album_count: the stored
+              summary counts albums the artist only appears on, and only settles
+              on the next rescan.
+            */}
+            {albumsPage.totalCount > 0 ? (
+              <StatChip icon="albums-outline" label={formatCount(albumsPage.totalCount, 'album')} />
             ) : null}
             <StatChip icon="musical-notes-outline" label={formatCount(allPage.totalCount, 'track')} />
             {detail.totalDuration > 0 ? (
@@ -376,6 +384,7 @@ export default function ArtistScreen() {
 
 function buildListItems(
   detail: ArtistDetail,
+  albumCount: number,
   songCount: number,
   appearanceCount: number
 ): ArtistPageItem[] {
@@ -391,12 +400,15 @@ function buildListItems(
       key: 'section-albums',
       type: 'section',
       title: 'Albums',
-      trailing: formatCount(detail.albums.length, 'album'),
+      trailing: formatCount(albumCount, 'album'),
       target: 'albums',
     });
     items.push({ key: 'albums', type: 'albums' });
   }
 
+  // An artist who only guests on other people's albums has no songs of their
+  // own, and a bare "Songs · 0 tracks" header reads as a loading failure.
+  if (songCount > 0) {
     items.push({
       key: 'section-songs',
       type: 'section',
@@ -407,6 +419,7 @@ function buildListItems(
     detail.songTracks.slice(0, SONG_PREVIEW_LIMIT).forEach((track, index) => {
       items.push({ key: `song-${track.id}`, type: 'track', track, section: 'songs', index });
     });
+  }
 
   if (detail.showAppearances) {
     items.push({

src/library/artistDetail.ts

@@ -2,7 +2,6 @@ import {
   filterTracksByArtist,
   normalizeKey,
   resolveCanonicalBrowseArtist,
-  splitAlbumArtistCollaborators,
   type ArtistGroupingMode,
 } from '@/library/artistGrouping';
 import type { DbTrack } from '@/types/library';
@@ -60,14 +59,16 @@ export function buildArtistDetail(
   };
 }
 
+/**
+ * "Main" means the album is theirs, so the test is the canonical primary artist
+ * and nothing else — the same rule the native read model uses to mark an index
+ * row 'song' rather than 'appearance'. Matching on the raw track artist as well
+ * made a Various Artists compilation count as a main album for every featured
+ * performer on it.
+ */
 function isMainArtistTrack(track: DbTrack, artistKey: string): boolean {
   if (!artistKey) return false;
-  if (normalizeKey(resolveCanonicalBrowseArtist(track)) === artistKey) return true;
-  if (normalizeKey(track.artist) === artistKey) return true;
-  if (normalizeKey(track.album_artist ?? '') === artistKey) return true;
-  return splitAlbumArtistCollaborators(track.album_artist ?? '').some(
-    (name) => normalizeKey(name) === artistKey
-  );
+  return normalizeKey(resolveCanonicalBrowseArtist(track)) === artistKey;
 }
 
 function buildArtistAlbums(tracks: readonly DbTrack[]): ArtistAlbum[] {

src/library/artistGrouping.test.mts

@@ -83,6 +83,45 @@ test('file-tags artist records count every indexed track as primary', () => {
   assert.ok(artists.every((artist) => artist.primary_track_count === artist.track_count));
 });
 
+test('a compilation counts as an album only for its album artist', () => {
+  const compilation = {
+    album_artist: 'Various Artists',
+    album_identity_key: 'album:comp',
+    artwork_hash: 'comp-art',
+  };
+  const artists = buildArtistList([
+    createTrack({ artist: 'Yoko Takahashi', ...compilation }),
+    createTrack({ artist: 'Megumi Hayashibara', ...compilation }),
+    createTrack({
+      artist: 'Yoko Takahashi',
+      album_artist: 'Yoko Takahashi',
+      album_identity_key: 'album:own',
+      artwork_hash: 'own-art',
+    }),
+  ], 'astra');
+
+  const byName = new Map(artists.map((artist) => [artist.artist, artist]));
+
+  // Featured on the compilation, but it is not one of her albums — only the
+  // record she is the album artist of counts. Her track total still includes it.
+  const featured = byName.get('Yoko Takahashi');
+  assert.ok(featured);
+  assert.equal(featured.track_count, 2);
+  assert.equal(featured.album_count, 1);
+
+  // Nothing but the compilation: no albums, but the cover still feeds the mosaic.
+  const appearanceOnly = byName.get('Megumi Hayashibara');
+  assert.ok(appearanceOnly);
+  assert.equal(appearanceOnly.track_count, 1);
+  assert.equal(appearanceOnly.primary_track_count, 0);
+  assert.equal(appearanceOnly.album_count, 0);
+  assert.deepEqual(appearanceOnly.artwork_hashes, ['comp-art']);
+
+  const various = byName.get('Various Artists');
+  assert.ok(various);
+  assert.equal(various.album_count, 1);
+});
+
 test('artist browse filter defaults to primary artists and restores collab-only artists', () => {
   const artists = buildArtistList([
     createTrack({ artist: 'Primary Artist feat. Guest Artist' }),

src/library/artistGrouping.ts

@@ -209,8 +209,13 @@ export function buildArtistList(tracks: readonly ArtistTrackLike[], mode: Artist
         byKey.set(key, aggregate);
       }
       aggregate.track_count += 1;
-      if (key === primaryArtistKey) aggregate.primary_track_count += 1;
+      if (key === primaryArtistKey) {
+        aggregate.primary_track_count += 1;
+        // Albums the artist only guests on are not their albums; counting them
+        // here credited a Various Artists compilation to every featured
+        // performer. albumArtwork below stays ungated so they keep a mosaic.
         aggregate.albumKeys.add(track.album_identity_key);
+      }
 
       if (!track.artwork_hash) continue;
       if (!aggregate.albumArtwork.has(track.album_identity_key)) {