fix(editing songs): track number removed when editing multiple songs

Closes #1740.

app/Services/SongService.php

@@ -38,12 +38,26 @@ class SongService
         }
 
         return DB::transaction(function () use ($ids, $data): Collection {
-            return collect($ids)->reduce(function (Collection $updated, string $id) use ($data): Collection {
+            $multiSong = count($ids) > 1;
+            $noTrackUpdate = $multiSong && !$data->track;
+
+            return collect($ids)
+                ->reduce(function (Collection $updated, string $id) use ($data, $noTrackUpdate): Collection {
+                    $foundSong = Song::query()->with('album.artist')->find($id);
+
+                    if ($noTrackUpdate) {
+                        $data->track = $foundSong->track;
+                    }
+
                     optional(
-                    Song::query()->with('album.artist')->find($id),
+                        $foundSong,
                         fn (Song $song) => $updated->push($this->updateSong($song, clone $data)) // @phpstan-ignore-line
                     );
 
+                    if ($noTrackUpdate) {
+                        $data->track = null;
+                    }
+
                     return $updated;
                 }, collect());
         });

tests/Integration/Services/SongServiceTest.php

@@ -0,0 +1,170 @@
+<?php
+
+namespace Tests\Integration\Services;
+
+use App\Models\Song;
+use App\Services\SongService;
+use App\Values\SongUpdateData;
+use Illuminate\Support\Facades\DB;
+use Tests\TestCase;
+
+use function Tests\create_user;
+
+class SongServiceTest extends TestCase
+{
+    private SongService $service;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->service = app(SongService::class);
+
+        $user = create_user();
+        $this->actingAs($user);
+    }
+
+    public function testUpdateSingleSong(): void
+    {
+        $song = Song::factory()->create();
+
+        $data = SongUpdateData::make(
+            title: null,
+            artistName: null,
+            albumName: null,
+            albumArtistName: 'Artist A',
+            track: null,
+            disc: 1,
+            genre: null,
+            year: null,
+            lyrics: null
+        );
+
+        $expectedData = [
+            'disc' => 1,
+            'track' => 0,
+            'lyrics' => '',
+            'year' => null,
+            'genre' => '',
+            'albumArtistName' => 'Artist A',
+        ];
+
+        DB::shouldReceive('transaction')->andReturnUsing(static function ($callback) {
+            return $callback();
+        });
+
+        $updatedSongs = $this->service->updateSongs([$song->id], $data);
+
+        $this->assertEquals(1, $updatedSongs->count());
+        $this->assertEquals($expectedData['disc'], $updatedSongs->first()->disc);
+        $this->assertEquals($expectedData['track'], $updatedSongs->first()->track);
+        $this->assertEquals($expectedData['lyrics'], $updatedSongs->first()->lyrics);
+        $this->assertEquals($expectedData['genre'], $updatedSongs->first()->genre);
+    }
+
+    public function testUpdateMultipleSongsTrackProvided(): void
+    {
+        $song1 = Song::factory()->create([
+            'track' => 1,
+        ]);
+        $song2 = Song::factory()->create([
+            'track' => 2,
+        ]);
+
+        $albumArtistName = 'New Album Artist';
+        $lyrics = 'Lyrics 2';
+        $data = SongUpdateData::make(
+            title: null,
+            artistName: 'Arist B',
+            albumName: null,
+            albumArtistName: $albumArtistName,
+            track: 5,
+            disc: 2,
+            genre: 'Pop',
+            year: 2023,
+            lyrics: $lyrics
+        );
+
+        $expectedData = [
+            'disc' => 2,
+            'track' => 5,
+            'lyrics' => $lyrics,
+            'year' => 2023,
+            'genre' => 'Pop',
+            'albumArtistName' => $albumArtistName,
+        ];
+
+        DB::shouldReceive('transaction')->andReturnUsing(static function ($callback) {
+            return $callback();
+        });
+
+        $updatedSongs = $this->service->updateSongs([$song1->id, $song2->id], $data);
+
+        $this->assertEquals(2, $updatedSongs->count());
+
+        foreach ($updatedSongs as $updatedSong) {
+            $this->assertEquals($expectedData['disc'], $updatedSong->disc);
+            $this->assertEquals($expectedData['track'], $updatedSong->track);
+            $this->assertEquals($expectedData['lyrics'], $updatedSong->lyrics);
+            $this->assertEquals($expectedData['genre'], $updatedSong->genre);
+        }
+    }
+
+    public function testUpdateMultipleTracksWithoutProvidingTrack(): void
+    {
+        $song1 = Song::factory()->create(['track' => 1, 'disc' => 1]);
+        $song2 = Song::factory()->create(['track' => 2, 'disc' => 1]);
+
+        $lyrics = 'Lyrics';
+        $genre = 'Genre';
+
+        $data = SongUpdateData::make(
+            title: null,
+            artistName: 'Artist',
+            albumName: null,
+            albumArtistName: null,
+            track: null,
+            disc: null,
+            genre: 'Genre',
+            year: null,
+            lyrics: $lyrics
+        );
+
+
+        $expectedData1 = [
+            'disc' => 1,
+            'track' => 1,
+            'lyrics' => $lyrics,
+            'year' => null,
+            'genre' => $genre,
+            'albumArtistName' => null,
+        ];
+
+        $expectedData2 = [
+            'disc' => 1,
+            'track' => 2,
+            'lyrics' => $lyrics,
+            'year' => null,
+            'genre' => $genre,
+            'albumArtistName' => null,
+        ];
+
+        DB::shouldReceive('transaction')->andReturnUsing(static function ($callback) {
+            return $callback();
+        });
+
+        $updatedSongs = $this->service->updateSongs([$song1->id, $song2->id], $data);
+
+        $this->assertEquals(2, $updatedSongs->count());
+
+        $this->assertEquals($expectedData1['disc'], $updatedSongs[0]->disc);
+        $this->assertEquals($expectedData1['track'], $updatedSongs[0]->track);
+        $this->assertEquals($expectedData1['lyrics'], $updatedSongs[0]->lyrics);
+        $this->assertEquals($expectedData1['genre'], $updatedSongs[0]->genre);
+
+        $this->assertEquals($expectedData2['disc'], $updatedSongs[1]->disc);
+        $this->assertEquals($expectedData2['track'], $updatedSongs[1]->track);
+        $this->assertEquals($expectedData2['lyrics'], $updatedSongs[1]->lyrics);
+        $this->assertEquals($expectedData2['genre'], $updatedSongs[1]->genre);
+    }
+}