feat(metadata): add a primary artist tag mode

Artist Tag Mode gains "Primary artist only": downloads and re-enrichment write only the first credited artist to Artist and Album Artist, so players list one artist. The FFmpeg MP3, M4A and Vorbis embeds and the AC-4 path now honor the mode; MP3 and M4A previously ignored it.

Manual metadata edits, lyrics embedding and format conversion keep existing or typed credits joined instead of dropping names. The picker scrolls so three options fit on small and landscape screens. Closes #618.

lib/l10n/arb/app_en.arb

@@ -403,6 +403,14 @@
   "@optionsArtistTagModeSplitVorbisSubtitle": {
     "description": "Subtitle for split Vorbis artist tag mode"
   },
+  "optionsArtistTagModePrimary": "Primary artist only",
+  "@optionsArtistTagModePrimary": {
+    "description": "Artist tag mode option that writes only the first credited artist"
+  },
+  "optionsArtistTagModePrimarySubtitle": "Write only the first artist, like \"Artist A\", to Artist and Album Artist in every format, so players list one artist.",
+  "@optionsArtistTagModePrimarySubtitle": {
+    "description": "Subtitle for the primary-artist tag mode. Applies when downloading and re-enriching; manual edits keep what the user typed."
+  },
   "optionsExtensionStore": "Extension Repo",
   "@optionsExtensionStore": {
     "description": "Show/hide repo tab"

lib/l10n/arb/app_id.arb

@@ -360,6 +360,8 @@
   "@optionsArtistTagModeSplitVorbisSubtitle": {
     "description": "Subtitle for split Vorbis artist tag mode"
   },
+  "optionsArtistTagModePrimary": "Artis utama saja",
+  "optionsArtistTagModePrimarySubtitle": "Tulis hanya artis pertama, seperti \"Artis A\", ke Artis dan Artis Album di semua format, agar pemutar menampilkan satu artis.",
   "optionsExtensionStore": "Repo Ekstensi",
   "@optionsExtensionStore": {
     "description": "Show/hide repo tab"

lib/models/settings.dart

@@ -26,7 +26,7 @@ class AppSettings {
   /// Zero preserves the provider's original image.
   final int embeddedCoverMaxDimension;
   final String
-  artistTagMode; // 'joined' or 'split_vorbis' for Vorbis-based formats
+  artistTagMode; // 'joined', 'split_vorbis' (Vorbis formats), or 'primary'
   final bool embedLyrics;
   final bool embedReplayGain;
   // Apply ReplayGain/R128 tags as volume normalization in the built-in player.

lib/providers/download_queue_provider_embedding.dart

@@ -639,11 +639,19 @@ extension _DownloadQueueEmbedding on DownloadQueueNotifier {
       // no-op for non-AC-4 files, so other m4a downloads fall through to FFmpeg.
       if (isM4a) {
         try {
+          // The AC-4 writer takes no artist mode; resolve it here.
           final ac4Meta = <String, String>{
             'title': track.name,
-            'artist': track.artistName,
+            'artist': artistTagValueForMode(
+              track.artistName,
+              settings.artistTagMode,
+            ),
             'album': track.albumName,
-            'albumArtist': ?albumArtist,
+            if (albumArtist != null)
+              'albumArtist': artistTagValueForMode(
+                albumArtist,
+                settings.artistTagMode,
+              ),
             if (track.releaseDate != null) 'date': track.releaseDate!,
             if (resolvedGenre != null && resolvedGenre.isNotEmpty)
               'genre': resolvedGenre,
@@ -761,12 +769,14 @@ extension _DownloadQueueEmbedding on DownloadQueueNotifier {
             m4aPath: filePath,
             coverPath: validCover,
             metadata: metadata,
+            artistTagMode: settings.artistTagMode,
           );
         } else if (isMp3) {
           ffmpegResult = await FFmpegService.embedMetadataToMp3(
             mp3Path: filePath,
             coverPath: validCover,
             metadata: metadata,
+            artistTagMode: settings.artistTagMode,
           );
         } else {
           ffmpegResult = await FFmpegService.embedMetadataToOpus(

lib/providers/settings_provider.dart

@@ -607,7 +607,7 @@ class SettingsNotifier extends Notifier<AppSettings> {
   }
 
   void setArtistTagMode(String mode) {
-    if (mode == artistTagModeJoined || mode == artistTagModeSplitVorbis) {
+    if (artistTagModes.contains(mode)) {
       state = state.copyWith(artistTagMode: mode);
       _saveSettings();
     }

lib/screens/settings/metadata_settings_page.dart

@@ -155,6 +155,8 @@ class MetadataSettingsPage extends ConsumerWidget {
     switch (mode) {
       case artistTagModeSplitVorbis:
         return context.l10n.optionsArtistTagModeSplitVorbis;
+      case artistTagModePrimary:
+        return context.l10n.optionsArtistTagModePrimary;
       default:
         return context.l10n.optionsArtistTagModeJoined;
     }
@@ -240,62 +242,83 @@ class MetadataSettingsPage extends ConsumerWidget {
     showAppModalBottomSheet<void>(
       context: context,
       useRootNavigator: true,
+      // Three described options can exceed the default sheet height on
+      // small or landscape screens, as the cover-size picker above does.
+      isScrollControlled: true,
       backgroundColor: colorScheme.surfaceContainerHigh,
       builder: (context) => SafeArea(
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            Padding(
-              padding: const EdgeInsets.fromLTRB(24, 24, 24, 8),
-              child: Text(
-                context.l10n.optionsArtistTagMode,
-                style: Theme.of(
-                  context,
-                ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
-              ),
-            ),
-            Padding(
-              padding: const EdgeInsets.fromLTRB(24, 0, 24, 16),
-              child: Text(
-                context.l10n.optionsArtistTagModeDescription,
-                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
-                  color: colorScheme.onSurfaceVariant,
+        child: SingleChildScrollView(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Padding(
+                padding: const EdgeInsets.fromLTRB(24, 24, 24, 8),
+                child: Text(
+                  context.l10n.optionsArtistTagMode,
+                  style: Theme.of(
+                    context,
+                  ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
                 ),
               ),
-            ),
-            AppSheetOption(
-              leading: const Icon(Icons.segment_outlined),
-              title: Text(context.l10n.optionsArtistTagModeJoined),
-              subtitle: Text(context.l10n.optionsArtistTagModeJoinedSubtitle),
-              trailing: currentMode == artistTagModeJoined
-                  ? const Icon(Icons.check)
-                  : null,
-              onTap: () {
-                ref
-                    .read(settingsProvider.notifier)
-                    .setArtistTagMode(artistTagModeJoined);
-                Navigator.pop(context);
-              },
-            ),
-            AppSheetOption(
-              leading: const Icon(Icons.library_music_outlined),
-              title: Text(context.l10n.optionsArtistTagModeSplitVorbis),
-              subtitle: Text(
-                context.l10n.optionsArtistTagModeSplitVorbisSubtitle,
+              Padding(
+                padding: const EdgeInsets.fromLTRB(24, 0, 24, 16),
+                child: Text(
+                  context.l10n.optionsArtistTagModeDescription,
+                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                    color: colorScheme.onSurfaceVariant,
+                  ),
+                ),
               ),
-              trailing: currentMode == artistTagModeSplitVorbis
-                  ? const Icon(Icons.check)
-                  : null,
-              onTap: () {
-                ref
-                    .read(settingsProvider.notifier)
-                    .setArtistTagMode(artistTagModeSplitVorbis);
-                Navigator.pop(context);
-              },
-            ),
-            const SizedBox(height: 16),
-          ],
+              AppSheetOption(
+                leading: const Icon(Icons.segment_outlined),
+                title: Text(context.l10n.optionsArtistTagModeJoined),
+                subtitle: Text(context.l10n.optionsArtistTagModeJoinedSubtitle),
+                trailing: currentMode == artistTagModeJoined
+                    ? const Icon(Icons.check)
+                    : null,
+                onTap: () {
+                  ref
+                      .read(settingsProvider.notifier)
+                      .setArtistTagMode(artistTagModeJoined);
+                  Navigator.pop(context);
+                },
+              ),
+              AppSheetOption(
+                leading: const Icon(Icons.library_music_outlined),
+                title: Text(context.l10n.optionsArtistTagModeSplitVorbis),
+                subtitle: Text(
+                  context.l10n.optionsArtistTagModeSplitVorbisSubtitle,
+                ),
+                trailing: currentMode == artistTagModeSplitVorbis
+                    ? const Icon(Icons.check)
+                    : null,
+                onTap: () {
+                  ref
+                      .read(settingsProvider.notifier)
+                      .setArtistTagMode(artistTagModeSplitVorbis);
+                  Navigator.pop(context);
+                },
+              ),
+              AppSheetOption(
+                leading: const Icon(Icons.person_outline),
+                title: Text(context.l10n.optionsArtistTagModePrimary),
+                subtitle: Text(
+                  context.l10n.optionsArtistTagModePrimarySubtitle,
+                ),
+                trailing: currentMode == artistTagModePrimary
+                    ? const Icon(Icons.check)
+                    : null,
+                onTap: () {
+                  ref
+                      .read(settingsProvider.notifier)
+                      .setArtistTagMode(artistTagModePrimary);
+                  Navigator.pop(context);
+                },
+              ),
+              const SizedBox(height: 16),
+            ],
+          ),
         ),
       ),
     );

lib/screens/settings/settings_search_catalog.dart

@@ -275,7 +275,11 @@ class SettingsSearchCatalog {
         SettingsSearchEntry(
           icon: Icons.people_alt_outlined,
           title: l10n.optionsArtistTagMode,
-          keywords: const ['artist separator', 'multiple artists'],
+          keywords: const [
+            'artist separator',
+            'multiple artists',
+            'primary artist',
+          ],
         ),
         SettingsSearchEntry(
           icon: Icons.photo_size_select_large_outlined,

lib/screens/track_metadata_actions.dart

@@ -69,7 +69,10 @@ extension _TrackMetadataFileActions on _TrackMetadataScreenState {
         durationMs: initialDurationSeconds > 0
             ? initialDurationSeconds * 1000
             : 0,
-        artistTagMode: ref.read(settingsProvider).artistTagMode,
+        // Typed artist names are saved as entered, even in primary mode.
+        artistTagMode: artistTagModeForExistingTags(
+          ref.read(settingsProvider).artistTagMode,
+        ),
       ),
     );
 

lib/screens/track_metadata_lyrics.dart

@@ -546,7 +546,11 @@ extension _TrackMetadataLyricsAndSaving on _TrackMetadataScreenState {
           }
         } catch (_) {}
 
-        final artistTagMode = ref.read(settingsProvider).artistTagMode;
+        // Embedding lyrics rewrites the tags read above; it must not drop
+        // existing artist credits, so the primary mode keeps them joined.
+        final artistTagMode = artistTagModeForExistingTags(
+          ref.read(settingsProvider).artistTagMode,
+        );
         String? ffmpegResult;
         if (isMp3) {
           ffmpegResult = await FFmpegService.embedMetadataToMp3(
@@ -1110,12 +1114,14 @@ extension _TrackMetadataLyricsAndSaving on _TrackMetadataScreenState {
               mp3Path: ffmpegTarget,
               coverPath: effectiveCoverPath,
               metadata: metadata,
+              artistTagMode: artistTagMode,
             );
           } else if (lower.endsWith('.m4a') || lower.endsWith('.aac')) {
             ffmpegResult = await FFmpegService.embedMetadataToM4a(
               m4aPath: ffmpegTarget,
               coverPath: effectiveCoverPath,
               metadata: metadata,
+              artistTagMode: artistTagMode,
             );
           } else if (lower.endsWith('.opus') || lower.endsWith('.ogg')) {
             ffmpegResult = await FFmpegService.embedMetadataToOpus(

lib/services/audio_metadata_mapper.dart

@@ -406,7 +406,7 @@ class AudioMetadataMapper {
     }
 
     if (!shouldSplitVorbisArtistTags(artistTagMode)) {
-      entries.add(MapEntry(key, value));
+      entries.add(MapEntry(key, artistTagValueForMode(value, artistTagMode)));
       return;
     }
 

lib/services/ffmpeg_service.dart

@@ -1343,8 +1343,13 @@ class FFmpegService {
     required String mp3Path,
     String? coverPath,
     Map<String, String>? metadata,
+    String artistTagMode = artistTagModeJoined,
     bool preserveMetadata = false,
   }) async {
+    // ID3 keeps one artist frame: only the primary mode changes its value.
+    if (metadata != null) {
+      metadata = applyArtistTagModeToMetadata(metadata, artistTagMode);
+    }
     final tempDir = await getTemporaryDirectory();
     final tempOutput = _nextTempEmbedPath(tempDir.path, '.mp3');
     final lyrics = AudioMetadataMapper.extractLyricsForId3(metadata);
@@ -1614,8 +1619,13 @@ class FFmpegService {
     required String m4aPath,
     String? coverPath,
     Map<String, String>? metadata,
+    String artistTagMode = artistTagModeJoined,
     bool preserveMetadata = true,
   }) async {
+    // MP4 keeps one artist atom: only the primary mode changes its value.
+    if (metadata != null) {
+      metadata = applyArtistTagModeToMetadata(metadata, artistTagMode);
+    }
     final tempDir = await getTemporaryDirectory();
     final tempOutput = _nextTempEmbedPath(tempDir.path, '.m4a');
 
@@ -1866,6 +1876,10 @@ class FFmpegService {
       _log.e('Unsupported target format: $targetFormat');
       return null;
     }
+    // Conversion carries existing tags over. Primary mode applies to provider
+    // credits (download, re-enrichment) and must not drop names here; the
+    // download auto-conversion embeds its credits after this step.
+    artistTagMode = artistTagModeForExistingTags(artistTagMode);
 
     final resolvedLosslessQuality = isLosslessConversionTarget(format)
         ? await _resolveLosslessQuality(
@@ -1947,12 +1961,14 @@ class FFmpegService {
           mp3Path: outputPath,
           coverPath: coverPath,
           metadata: metadata,
+          artistTagMode: artistTagMode,
         );
       } else if (format == 'aac') {
         embedResult = await embedMetadataToM4a(
           m4aPath: outputPath,
           coverPath: coverPath,
           metadata: metadata,
+          artistTagMode: artistTagMode,
           preserveMetadata: true,
         );
       } else {

lib/utils/artist_utils.dart

@@ -5,6 +5,22 @@ final RegExp _artistNameSplitPattern = RegExp(
 
 const artistTagModeJoined = 'joined';
 const artistTagModeSplitVorbis = 'split_vorbis';
+const artistTagModePrimary = 'primary';
+
+const artistTagModes = {
+  artistTagModeJoined,
+  artistTagModeSplitVorbis,
+  artistTagModePrimary,
+};
+
+// Same separator set as the Rust tag writer and the Android finalizer, so
+// every write path stores the same primary artist. Unlike the display split
+// above, a standalone "x" needs spaces on both sides ("Malcolm X" stays).
+final RegExp _primaryArtistSeparator = RegExp(
+  r'\s*[,;&]\s*|\s+x\s+|\s+(?:feat(?:uring)?|ft|with)\.?(?:\s+|$)',
+  caseSensitive: false,
+);
+final RegExp _metadataKeyPunctuation = RegExp(r'[^A-Z0-9]');
 
 List<String> splitArtistNames(String rawArtists) {
   final raw = rawArtists.trim();
@@ -37,6 +53,51 @@ bool shouldSplitVorbisArtistTags(String mode) {
   return mode == artistTagModeSplitVorbis;
 }
 
+bool isPrimaryArtistTagMode(String mode) =>
+    mode.trim().toLowerCase() == artistTagModePrimary;
+
+/// The first credited artist, or the trimmed value when nothing separates it.
+String primaryArtistTagValue(String rawArtists) {
+  final trimmed = rawArtists.trim();
+  for (final part in trimmed.split(_primaryArtistSeparator)) {
+    final artist = part.trim();
+    if (artist.isNotEmpty) return artist;
+  }
+  return trimmed;
+}
+
+/// Mode for rewriting tags that already exist or that the user typed (editor,
+/// lyrics embedding). Primary is meant for provider credits at download and
+/// re-enrichment time and would silently discard names here.
+String artistTagModeForExistingTags(String mode) =>
+    isPrimaryArtistTagMode(mode) ? artistTagModeJoined : mode;
+
+/// Artist tag value written for [mode]. Joined and split modes keep the full
+/// credit; Vorbis splitting happens in the writers.
+String artistTagValueForMode(String value, String mode) =>
+    isPrimaryArtistTagMode(mode) ? primaryArtistTagValue(value) : value;
+
+/// Rewrites artist and album-artist entries of an embed metadata map for
+/// [mode], whichever key spelling the caller used (ARTIST, album_artist,
+/// "ALBUM ARTIST", albumArtist). Other entries and empty values are kept.
+Map<String, String> applyArtistTagModeToMetadata(
+  Map<String, String> metadata,
+  String mode,
+) {
+  if (!isPrimaryArtistTagMode(mode)) return metadata;
+  return {
+    for (final entry in metadata.entries)
+      entry.key: switch (entry.key.toUpperCase().replaceAll(
+        _metadataKeyPunctuation,
+        '',
+      )) {
+        'ARTIST' || 'ALBUMARTIST' when entry.value.trim().isNotEmpty =>
+          primaryArtistTagValue(entry.value),
+        _ => entry.value,
+      },
+  };
+}
+
 List<String> splitArtistTagValues(String rawArtists) {
   final seen = <String>{};
   final values = <String>[];

lib/utils/ffmpeg_reenrich.dart

@@ -97,6 +97,7 @@ Future<bool> applyFfmpegReEnrichResult({
         mp3Path: ffmpegTarget,
         coverPath: effectiveCoverPath,
         metadata: metadata,
+        artistTagMode: artistTagMode,
         preserveMetadata: true,
       );
     } else if (isM4A) {
@@ -104,6 +105,7 @@ Future<bool> applyFfmpegReEnrichResult({
         m4aPath: ffmpegTarget,
         coverPath: effectiveCoverPath,
         metadata: metadata,
+        artistTagMode: artistTagMode,
         preserveMetadata: true,
       );
     } else if (isOpus) {

test/artist_tag_mode_settings_test.dart

@@ -0,0 +1,79 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:spotiflac_android/l10n/app_localizations.dart';
+import 'package:spotiflac_android/models/settings.dart';
+import 'package:spotiflac_android/providers/settings_provider.dart';
+import 'package:spotiflac_android/screens/settings/metadata_settings_page.dart';
+import 'package:spotiflac_android/utils/artist_utils.dart';
+
+/// Skips loading persisted settings; mode changes use the real validation.
+class _Settings extends SettingsNotifier {
+  @override
+  AppSettings build() => const AppSettings();
+}
+
+void main() {
+  setUp(() => SharedPreferences.setMockInitialValues({}));
+
+  test('primary artist mode survives settings round trips', () {
+    final settings = const AppSettings().copyWith(
+      artistTagMode: artistTagModePrimary,
+    );
+    expect(
+      AppSettings.fromJson(settings.toJson()).artistTagMode,
+      artistTagModePrimary,
+    );
+  });
+
+  for (final size in [const Size(390, 844), const Size(844, 390)]) {
+    testWidgets('picker offers and saves the primary artist mode ($size)', (
+      tester,
+    ) async {
+      tester.view.physicalSize = size;
+      tester.view.devicePixelRatio = 1;
+      addTearDown(tester.view.reset);
+      final container = ProviderContainer(
+        overrides: [settingsProvider.overrideWith(_Settings.new)],
+      );
+      addTearDown(container.dispose);
+      await tester.pumpWidget(
+        UncontrolledProviderScope(
+          container: container,
+          child: const MaterialApp(
+            localizationsDelegates: AppLocalizations.localizationsDelegates,
+            supportedLocales: AppLocalizations.supportedLocales,
+            home: MetadataSettingsPage(),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // The row subtitle names the current mode before the picker opens.
+      expect(find.text('Single joined value'), findsOneWidget);
+      await tester.tap(find.text('Artist Tag Mode'));
+      await tester.pumpAndSettle();
+      Finder inSheet(String text) => find.descendant(
+        of: find.byType(BottomSheet),
+        matching: find.text(text),
+      );
+      expect(inSheet('Single joined value'), findsOneWidget);
+      expect(inSheet('Split tags for FLAC/Opus'), findsOneWidget);
+      final primary = inSheet('Primary artist only');
+      await tester.ensureVisible(primary);
+      await tester.pumpAndSettle();
+      await tester.tap(primary);
+      await tester.pumpAndSettle();
+
+      expect(container.read(settingsProvider).artistTagMode, 'primary');
+      expect(find.byType(BottomSheet), findsNothing);
+      // The settings row now names the selected mode.
+      expect(find.text('Primary artist only'), findsOneWidget);
+      expect(tester.takeException(), isNull);
+
+      container.read(settingsProvider.notifier).setArtistTagMode('unknown');
+      expect(container.read(settingsProvider).artistTagMode, 'primary');
+    });
+  }
+}

test/maintainability_contracts_test.dart

@@ -305,6 +305,21 @@ void main() {
         entries.where((entry) => entry.key == 'TITLE').single.value,
         'Track',
       );
+      final primary = AudioMetadataMapper.buildVorbisMetadataEntries({
+        'ARTIST': 'First & Second',
+        'ALBUMARTIST': 'First, Second',
+        'TITLE': 'Track',
+      }, artistTagMode: artistTagModePrimary);
+      expect(
+        primary.where((entry) => entry.key == 'ARTIST').map((e) => e.value),
+        ['First'],
+      );
+      expect(
+        primary
+            .where((entry) => entry.key == 'ALBUMARTIST')
+            .map((e) => e.value),
+        ['First'],
+      );
       final advisory = AudioMetadataMapper.buildVorbisMetadataEntries({
         'EXPLICIT': 'true',
       }).single;

test/models_and_utils_test.dart

@@ -1355,6 +1355,76 @@ void main() {
       expect(shouldSplitVorbisArtistTags(artistTagModeSplitVorbis), isTrue);
       expect(shouldSplitVorbisArtistTags(artistTagModeJoined), isFalse);
     });
+
+    // Shared with the Rust and Kotlin primary-artist tests; keep in sync.
+    test('primary artist mode keeps the first credited artist', () {
+      for (final (input, expected) in [
+        ('Calle 24, Chino Pacas', 'Calle 24'),
+        ('Calle 24 & Chino Pacas', 'Calle 24'),
+        ('Artist A; Artist B', 'Artist A'),
+        ('Artist A feat. Artist B', 'Artist A'),
+        ('Artist A Feat Artist B', 'Artist A'),
+        ('Artist A ft. Artist B', 'Artist A'),
+        ('Artist A featuring Artist B', 'Artist A'),
+        ('Artist A with Artist B', 'Artist A'),
+        ('Artist A x Artist B', 'Artist A'),
+        ('Artist A X Artist B', 'Artist A'),
+        (' , Artist A, Artist B', 'Artist A'),
+        ('Malcolm X', 'Malcolm X'),
+        ('Artist Without Fear', 'Artist Without Fear'),
+        ('Maxx', 'Maxx'),
+        ('AC/DC', 'AC/DC'),
+        ('  Various Artists  ', 'Various Artists'),
+        ('', ''),
+      ]) {
+        expect(primaryArtistTagValue(input), expected, reason: input);
+        expect(
+          artistTagValueForMode(input, ' Primary '),
+          expected,
+          reason: input,
+        );
+      }
+      for (final mode in [artistTagModeJoined, artistTagModeSplitVorbis]) {
+        expect(artistTagValueForMode('A, B', mode), 'A, B');
+      }
+      expect(artistTagModes, contains(artistTagModePrimary));
+      expect(
+        artistTagModeForExistingTags(artistTagModePrimary),
+        artistTagModeJoined,
+      );
+      expect(
+        artistTagModeForExistingTags(artistTagModeSplitVorbis),
+        artistTagModeSplitVorbis,
+      );
+    });
+
+    test('primary artist mode rewrites every artist key spelling', () {
+      final metadata = {
+        'ARTIST': 'A, B',
+        'album_artist': 'A & B',
+        'ALBUM ARTIST': 'A feat. B',
+        'albumArtist': 'A x B',
+        'TITLE': 'A, B',
+        'COMPOSER': 'A, B',
+        'artist': '',
+      };
+      expect(applyArtistTagModeToMetadata(metadata, artistTagModePrimary), {
+        'ARTIST': 'A',
+        'album_artist': 'A',
+        'ALBUM ARTIST': 'A',
+        'albumArtist': 'A',
+        'TITLE': 'A, B',
+        'COMPOSER': 'A, B',
+        'artist': '',
+      });
+      expect(
+        identical(
+          applyArtistTagModeToMetadata(metadata, artistTagModeJoined),
+          metadata,
+        ),
+        isTrue,
+      );
+    });
   });
 
   group('audio conversion utils', () {