A lot of changes

backend/Core/Musify.Application/Albums/UpdateAlbum.cs

@@ -3,13 +3,8 @@ using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Musify.Application.Albums.Responses;
-using Musify.Application.Configuration;
 using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
-using Musify.Application.Services;
 using Musify.Application.Shared;
-using Musify.Domain.ValueObjects;
 
 namespace Musify.Application.Albums
 {
@@ -18,16 +13,12 @@ namespace Musify.Application.Albums
         Guid AlbumId,
         string Title,
         string? Description,
-        int? ReleaseYear,
-        Guid? NewPictureIntentId)
+        int? ReleaseYear)
         : ICommand<ErrorOr<AlbumApplicationResponse>>;
 
     public class UpdateAlbumCommandHandler(
-        IEventBus eventBus,
         IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<UpdateAlbumCommandHandler> logger,
-        AlbumConfiguration albumConfiguration)
+        ILogger<UpdateAlbumCommandHandler> logger)
         : ICommandHandler<UpdateAlbumCommand, ErrorOr<AlbumApplicationResponse>>
     {
         public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumCommand request, CancellationToken cancellationToken)
@@ -39,27 +30,12 @@ namespace Musify.Application.Albums
             var album = found.Value;
             var title = request.Title.Trim();
 
+            // This is a full replace of the plain fields; the picture has its own command.
             album.Title = title;
             album.NormalizedTitle = TextNormalizer.Normalize(title);
-            album.Description = request.Description;
+            album.Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim();
             album.ReleaseYear = request.ReleaseYear;
 
-            if (request.NewPictureIntentId is { } intentId)
-            {
-                var prepared = await PictureSourceChange.PrepareAsync(
-                    uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
-                if (prepared.IsError)
-                    return prepared.Errors;
-
-                var picture = prepared.Value;
-                album.Pictures = picture.Pictures;
-
-                await eventBus.PublishAsync(
-                    new UpdateAlbumPictureSourceEvent(
-                        album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                    cancellationToken);
-            }
-
             await database.SaveChangesAsync(cancellationToken);
 
             logger.LogInformation("Updated album {AlbumId}", album.Id);

backend/Core/Musify.Application/Albums/UpdateAlbumPicture.cs

@@ -0,0 +1,60 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Musify.Application.Albums.Responses;
+using Musify.Application.Configuration;
+using Musify.Application.Contracts;
+using Musify.Application.Events;
+using Musify.Application.Pictures;
+using Musify.Application.Services;
+using Musify.Application.Shared;
+using Musify.Domain.ValueObjects;
+
+namespace Musify.Application.Albums
+{
+    /// <summary>Replaces an album's picture with a previously uploaded image; the plain fields are untouched.</summary>
+    public record UpdateAlbumPictureCommand(long UserId, Guid AlbumId, Guid PictureIntentId)
+        : ICommand<ErrorOr<AlbumApplicationResponse>>;
+
+    public class UpdateAlbumPictureCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<UpdateAlbumPictureCommandHandler> logger,
+        AlbumConfiguration albumConfiguration)
+        : ICommandHandler<UpdateAlbumPictureCommand, ErrorOr<AlbumApplicationResponse>>
+    {
+        public async ValueTask<ErrorOr<AlbumApplicationResponse>> Handle(UpdateAlbumPictureCommand request, CancellationToken cancellationToken)
+        {
+            var found = await database.Albums.FindOwnedAsync(request.AlbumId, request.UserId, cancellationToken);
+            if (found.IsError)
+                return found.Errors;
+
+            var album = found.Value;
+
+            var prepared = await PictureSourceChange.PrepareAsync(
+                uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.AlbumPicture, albumConfiguration, cancellationToken);
+            if (prepared.IsError)
+                return prepared.Errors;
+
+            var picture = prepared.Value;
+            album.Pictures = picture.Pictures;
+
+            await eventBus.PublishAsync(
+                new UpdateAlbumPictureSourceEvent(
+                    album.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
+                cancellationToken);
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("Updated picture of album {AlbumId}", album.Id);
+
+            return await database.Albums
+                .AsNoTracking()
+                .Where(a => a.Id == album.Id)
+                .SelectResponse()
+                .SingleAsync(cancellationToken);
+        }
+    }
+}

backend/Core/Musify.Application/Genres/GetAvailableGenres.cs

@@ -11,7 +11,7 @@ namespace Musify.Application.Genres
     {
         public ValueTask<IReadOnlyList<AvailableGenreResponse>> Handle(GetAvailableGenresQuery request, CancellationToken cancellationToken)
         {
-            var all = Enum.GetValues<Genre>();
+            var all = Enum.GetValues<Genre>().Where(genre => genre != Genre.None).ToArray();
 
             IReadOnlyList<AvailableGenreResponse> result = all
                 .Select(genre => new AvailableGenreResponse(

backend/Core/Musify.Application/PlayLists/AddAlbumToPlayList.cs

@@ -7,6 +7,7 @@ using Musify.Application.Contracts;
 using Musify.Application.PlayLists.Responses;
 using Musify.Application.Shared;
 using Musify.Domain.Entities;
+using Musify.Domain.ValueObjects;
 
 namespace Musify.Application.PlayLists
 {
@@ -34,7 +35,7 @@ namespace Musify.Application.PlayLists
 
             var albumTrackIds = await database.AlbumHasTracks
                 .AsNoTracking()
-                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == Domain.ValueObjects.LifeCycleStatus.Active)
+                .Where(albumTrack => albumTrack.AlbumId == request.AlbumId && albumTrack.Track.LifeCycleStatus == LifeCycleStatus.Active)
                 .OrderBy(albumTrack => albumTrack.TrackNumber)
                 .Select(albumTrack => albumTrack.TrackId)
                 .ToListAsync(cancellationToken);
@@ -54,8 +55,9 @@ namespace Musify.Application.PlayLists
                 return new AddAlbumToPlayListResponse(0);
 
             // Playlist positions are internal indexes, so they start at 0.
-            var nextPosition = (await playListTracksQuery
-                .MaxAsync(link => (int?)link.Position, cancellationToken) ?? -1) + 1;
+            var nextPosition = existingTrackIds.Count > 0
+               ? await playListTracksQuery.MaxAsync(link => link.Position, cancellationToken) + 1
+                : 0;
 
             foreach (var trackId in newTrackIds)
             {

backend/Core/Musify.Application/PlayLists/AddTracksToPlayList.cs

@@ -47,9 +47,12 @@ namespace Musify.Application.PlayLists
                 return Result.Success;
 
             // Playlist positions are internal indexes, so they start at 0.
-            var nextPosition = (await database.PlayListHasTracks
-                .Where(link => link.PlayListId == request.PlayListId)
-                .MaxAsync(link => (int?)link.Position, cancellationToken) ?? -1) + 1;
+            var playListTracksQuery = database.PlayListHasTracks
+                .Where(link => link.PlayListId == request.PlayListId);
+
+            var nextPosition = await playListTracksQuery.AnyAsync(cancellationToken)
+               ? await playListTracksQuery.MaxAsync(link => link.Position, cancellationToken) + 1
+                : 0;
 
             foreach (var trackId in toAdd)
             {

backend/Core/Musify.Application/PlayLists/CreatePlayList.cs

@@ -39,10 +39,10 @@ namespace Musify.Application.PlayLists
                 return AppErrors.NotFound("User", request.UserId);
 
             PreparedPicture? picture = null;
-            if (request.PictureIntentId is { } intentId)
+            if (request.PictureIntentId.HasValue)
             {
                 var prepared = await PictureSourceChange.PrepareAsync(
-                    uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
+                    uploadIntentValidator, request.PictureIntentId.Value, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
                 if (prepared.IsError)
                     return prepared.Errors;
 

backend/Core/Musify.Application/PlayLists/UpdatePlayList.cs

@@ -2,12 +2,8 @@ using ErrorOr;
 using Mediator;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
-using Musify.Application.Configuration;
 using Musify.Application.Contracts;
-using Musify.Application.Events;
-using Musify.Application.Pictures;
 using Musify.Application.PlayLists.Responses;
-using Musify.Application.Services;
 using Musify.Application.Shared;
 using Musify.Domain.ValueObjects;
 
@@ -16,18 +12,14 @@ namespace Musify.Application.PlayLists
     public record UpdatePlayListCommand(
         long UserId,
         Guid PlayListId,
-        string? NewName,
+        string NewName,
         string? NewDescription,
-        Guid? NewPictureIntentId,
-        PlayListVisibility? NewVisibility = null)
+        PlayListVisibility NewVisibility)
         : ICommand<ErrorOr<PlayListApplicationResponse>>;
 
     public class UpdatePlayListCommandHandler(
-        IEventBus eventBus,
         IDatabase database,
-        UploadIntentValidator uploadIntentValidator,
-        ILogger<UpdatePlayListCommandHandler> logger,
-        PlayListConfiguration playListConfiguration)
+        ILogger<UpdatePlayListCommandHandler> logger)
         : ICommandHandler<UpdatePlayListCommand, ErrorOr<PlayListApplicationResponse>>
     {
         public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListCommand request, CancellationToken cancellationToken)
@@ -38,34 +30,11 @@ namespace Musify.Application.PlayLists
 
             var playList = found.Value;
 
-            if (!string.IsNullOrWhiteSpace(request.NewName))
-            {
-                playList.Name = request.NewName.Trim();
-                playList.NormalizedName = TextNormalizer.Normalize(request.NewName);
-            }
-
-            // null means "unchanged"; a blank description clears it.
-            if (request.NewDescription != null)
-                playList.Description = string.IsNullOrWhiteSpace(request.NewDescription) ? null : request.NewDescription.Trim();
-
-            if (request.NewVisibility is { } visibility)
-                playList.Visibility = visibility;
-
-            if (request.NewPictureIntentId is { } intentId)
-            {
-                var prepared = await PictureSourceChange.PrepareAsync(
-                    uploadIntentValidator, intentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
-                if (prepared.IsError)
-                    return prepared.Errors;
-
-                var picture = prepared.Value;
-                playList.Pictures = picture.Pictures;
-
-                await eventBus.PublishAsync(
-                    new UpdatePlayListPictureSourceEvent(
-                        playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
-                    cancellationToken);
-            }
+            // This is a full replace of the plain fields; the picture has its own command.
+            playList.Name = request.NewName.Trim();
+            playList.NormalizedName = TextNormalizer.Normalize(request.NewName);
+            playList.Description = string.IsNullOrWhiteSpace(request.NewDescription) ? null : request.NewDescription.Trim();
+            playList.Visibility = request.NewVisibility;
 
             await database.SaveChangesAsync(cancellationToken);
 

backend/Core/Musify.Application/PlayLists/UpdatePlayListPicture.cs

@@ -0,0 +1,60 @@
+using ErrorOr;
+using Mediator;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Musify.Application.Configuration;
+using Musify.Application.Contracts;
+using Musify.Application.Events;
+using Musify.Application.Pictures;
+using Musify.Application.PlayLists.Responses;
+using Musify.Application.Services;
+using Musify.Application.Shared;
+using Musify.Domain.ValueObjects;
+
+namespace Musify.Application.PlayLists
+{
+    /// <summary>Replaces a playlist's picture with a previously uploaded image; the plain fields are untouched.</summary>
+    public record UpdatePlayListPictureCommand(long UserId, Guid PlayListId, Guid PictureIntentId)
+        : ICommand<ErrorOr<PlayListApplicationResponse>>;
+
+    public class UpdatePlayListPictureCommandHandler(
+        IEventBus eventBus,
+        IDatabase database,
+        UploadIntentValidator uploadIntentValidator,
+        ILogger<UpdatePlayListPictureCommandHandler> logger,
+        PlayListConfiguration playListConfiguration)
+        : ICommandHandler<UpdatePlayListPictureCommand, ErrorOr<PlayListApplicationResponse>>
+    {
+        public async ValueTask<ErrorOr<PlayListApplicationResponse>> Handle(UpdatePlayListPictureCommand request, CancellationToken cancellationToken)
+        {
+            var found = await database.PlayLists.FindOwnedAsync(request.PlayListId, request.UserId, cancellationToken);
+            if (found.IsError)
+                return found.Errors;
+
+            var playList = found.Value;
+
+            var prepared = await PictureSourceChange.PrepareAsync(
+                uploadIntentValidator, request.PictureIntentId, request.UserId, UploadIntentPurpose.PlayListPicture, playListConfiguration, cancellationToken);
+            if (prepared.IsError)
+                return prepared.Errors;
+
+            var picture = prepared.Value;
+            playList.Pictures = picture.Pictures;
+
+            await eventBus.PublishAsync(
+                new UpdatePlayListPictureSourceEvent(
+                    playList.Id, picture.Intent.Id, picture.Intent.Bucket, picture.Intent.Key, picture.FinalKey, picture.Sizes),
+                cancellationToken);
+
+            await database.SaveChangesAsync(cancellationToken);
+
+            logger.LogInformation("Updated picture of playlist {PlayListId}", playList.Id);
+
+            return await database.PlayLists
+                .AsNoTracking()
+                .Where(p => p.Id == playList.Id)
+                .SelectResponse()
+                .SingleAsync(cancellationToken);
+        }
+    }
+}

backend/Core/Musify.Application/Tracks/CreateTrack.cs

@@ -90,7 +90,6 @@ namespace Musify.Application.Tracks
 
             await database.Tracks.AddAsync(trackEntity, cancellationToken);
 
-
             var sizes = trackConfiguration.PicturesSizes.ToImageSizes(trackConfiguration.Routes);
             await eventBus.PublishAsync(
                 new CreateTrackResourcesEvent(

backend/Core/Musify.Domain/ValueObjects/Genre.cs

@@ -2,31 +2,33 @@ namespace Musify.Domain.ValueObjects
 {
     public enum Genre
     {
-        Pop = 0,
-        Rock = 1,
-        HipHop = 2,
-        RnB = 3,
-        Jazz = 4,
-        Blues = 5,
-        Classical = 6,
-        Electronic = 7,
-        House = 8,
-        Techno = 9,
-        Trance = 10,
-        Dubstep = 11,
-        DrumAndBass = 12,
-        Metal = 13,
-        Punk = 14,
-        Reggae = 15,
-        Reggaeton = 16,
-        Country = 17,
-        Folk = 18,
-        Indie = 19,
-        KPop = 20,
-        Latin = 21,
-        Soul = 22,
-        Funk = 23,
-        Ambient = 24,
-        Lofi = 25
+        /// <summary>Unset value (the enum default); it is not a real genre and is never stored or offered to clients.</summary>
+        None = 0,
+        Pop = 1,
+        Rock = 2,
+        HipHop = 3,
+        RnB = 4,
+        Jazz = 5,
+        Blues = 6,
+        Classical = 7,
+        Electronic = 8,
+        House = 9,
+        Techno = 10,
+        Trance = 11,
+        Dubstep = 12,
+        DrumAndBass = 13,
+        Metal = 14,
+        Punk = 15,
+        Reggae = 16,
+        Reggaeton = 17,
+        Country = 18,
+        Folk = 19,
+        Indie = 20,
+        KPop = 21,
+        Latin = 22,
+        Soul = 23,
+        Funk = 24,
+        Ambient = 25,
+        Lofi = 26
     }
 }

backend/Core/Musify.Infrastructure/Persistence/Migrations/20260924154218_GenreNone.cs

@@ -0,0 +1,26 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Musify.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class GenreNone : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterDatabase()
+                .Annotation("Npgsql:Enum:genre", "ambient,blues,classical,country,drum_and_bass,dubstep,electronic,folk,funk,hip_hop,house,indie,jazz,k_pop,latin,lofi,metal,none,pop,punk,reggae,reggaeton,rn_b,rock,soul,techno,trance")
+                .OldAnnotation("Npgsql:Enum:genre", "ambient,blues,classical,country,drum_and_bass,dubstep,electronic,folk,funk,hip_hop,house,indie,jazz,k_pop,latin,lofi,metal,pop,punk,reggae,reggaeton,rn_b,rock,soul,techno,trance");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterDatabase()
+                .Annotation("Npgsql:Enum:genre", "ambient,blues,classical,country,drum_and_bass,dubstep,electronic,folk,funk,hip_hop,house,indie,jazz,k_pop,latin,lofi,metal,pop,punk,reggae,reggaeton,rn_b,rock,soul,techno,trance")
+                .OldAnnotation("Npgsql:Enum:genre", "ambient,blues,classical,country,drum_and_bass,dubstep,electronic,folk,funk,hip_hop,house,indie,jazz,k_pop,latin,lofi,metal,none,pop,punk,reggae,reggaeton,rn_b,rock,soul,techno,trance");
+        }
+    }
+}

backend/Core/Musify.Infrastructure/Persistence/Migrations/DatabaseModelSnapshot.cs

@@ -21,7 +21,7 @@ namespace Musify.Infrastructure.Persistence.Migrations
                 .HasAnnotation("ProductVersion", "10.0.12")
                 .HasAnnotation("Relational:MaxIdentifierLength", 63);
 
-            NpgsqlModelBuilderExtensions.HasPostgresEnum(modelBuilder, "genre", new[] { "ambient", "blues", "classical", "country", "drum_and_bass", "dubstep", "electronic", "folk", "funk", "hip_hop", "house", "indie", "jazz", "k_pop", "latin", "lofi", "metal", "pop", "punk", "reggae", "reggaeton", "rn_b", "rock", "soul", "techno", "trance" });
+            NpgsqlModelBuilderExtensions.HasPostgresEnum(modelBuilder, "genre", new[] { "ambient", "blues", "classical", "country", "drum_and_bass", "dubstep", "electronic", "folk", "funk", "hip_hop", "house", "indie", "jazz", "k_pop", "latin", "lofi", "metal", "none", "pop", "punk", "reggae", "reggaeton", "rn_b", "rock", "soul", "techno", "trance" });
             NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
 
             modelBuilder.Entity("MassTransit.EntityFrameworkCoreIntegration.InboxState", b =>

backend/Hosts/Musify.Api/DataTransferObjects/Albums/UpdateAlbumPictureRequest.cs

@@ -0,0 +1,4 @@
+namespace Musify.Api.DataTransferObjects.Albums
+{
+    public record UpdateAlbumPictureRequest(Guid PictureIntentId);
+}

backend/Hosts/Musify.Api/DataTransferObjects/Albums/UpdateAlbumRequest.cs

@@ -3,6 +3,5 @@ namespace Musify.Api.DataTransferObjects.Albums
     public record UpdateAlbumRequest(
         string Title,
         string? Description,
-        int? ReleaseYear,
-        Guid? PictureIntentId);
+        int? ReleaseYear);
 }

backend/Hosts/Musify.Api/DataTransferObjects/PlayLists/UpdatePlayListPictureRequest.cs

@@ -0,0 +1,4 @@
+namespace Musify.Api.DataTransferObjects.PlayLists
+{
+    public record UpdatePlayListPictureRequest(Guid PictureIntentId);
+}

backend/Hosts/Musify.Api/DataTransferObjects/PlayLists/UpdatePlayListRequest.cs

@@ -3,8 +3,7 @@ using Musify.Domain.ValueObjects;
 namespace Musify.Api.DataTransferObjects.PlayLists
 {
     public record UpdatePlayListRequest(
-        string? Name,
+        string Name,
         string? Description,
-        Guid? PictureIntentId,
-        PlayListVisibility? Visibility = null);
+        PlayListVisibility? Visibility);
 }

backend/Hosts/Musify.Api/Endpoints/AlbumEndpoints.cs

@@ -94,6 +94,17 @@ namespace Musify.Api.Endpoints
                 .Produces(StatusCodes.Status403Forbidden)
                 .Produces(StatusCodes.Status404NotFound);
 
+            group.MapPut("/{id:guid}/picture", UpdateAlbumPicture)
+                .WithName("UpdateAlbumPicture")
+                .WithSummary("Replace an album picture with an uploaded image")
+                .AddEndpointFilter<ValidationFilter<UpdateAlbumPictureRequest>>()
+                .RequireAuthorization()
+                .Produces<AlbumApplicationResponse>()
+                .ProducesValidationProblem()
+                .Produces(StatusCodes.Status401Unauthorized)
+                .Produces(StatusCodes.Status403Forbidden)
+                .Produces(StatusCodes.Status404NotFound);
+
             group.MapDelete("/{id:guid}", DeleteAlbum)
                 .WithName("DeleteAlbum")
                 .WithSummary("Delete an album")
@@ -229,7 +240,21 @@ namespace Musify.Api.Endpoints
             CancellationToken cancellationToken)
         {
             var result = await mediator.Send(
-                new UpdateAlbumCommand(currentUser.RequiredId, id, request.Title, request.Description, request.ReleaseYear, request.PictureIntentId),
+                new UpdateAlbumCommand(currentUser.RequiredId, id, request.Title, request.Description, request.ReleaseYear),
+                cancellationToken);
+
+            return result.ToHttpResult();
+        }
+
+        private static async Task<IResult> UpdateAlbumPicture(
+            IMediator mediator,
+            CurrentUser currentUser,
+            Guid id,
+            UpdateAlbumPictureRequest request,
+            CancellationToken cancellationToken)
+        {
+            var result = await mediator.Send(
+                new UpdateAlbumPictureCommand(currentUser.RequiredId, id, request.PictureIntentId),
                 cancellationToken);
 
             return result.ToHttpResult();

backend/Hosts/Musify.Api/Endpoints/PlayListEndpoints.cs

@@ -68,6 +68,17 @@ namespace Musify.Api.Endpoints
                 .Produces(StatusCodes.Status403Forbidden)
                 .Produces(StatusCodes.Status404NotFound);
 
+            group.MapPut("/{id:guid}/picture", UpdatePlayListPicture)
+                .WithName("UpdatePlayListPicture")
+                .WithSummary("Replace a playlist picture with an uploaded image")
+                .AddEndpointFilter<ValidationFilter<UpdatePlayListPictureRequest>>()
+                .RequireAuthorization()
+                .Produces<PlayListApplicationResponse>()
+                .ProducesValidationProblem()
+                .Produces(StatusCodes.Status401Unauthorized)
+                .Produces(StatusCodes.Status403Forbidden)
+                .Produces(StatusCodes.Status404NotFound);
+
             group.MapDelete("/{id:guid}", DeletePlayList)
                 .WithName("DeletePlayList")
                 .WithSummary("Delete a playlist")
@@ -185,7 +196,21 @@ namespace Musify.Api.Endpoints
             CancellationToken cancellationToken)
         {
             var result = await mediator.Send(
-                new UpdatePlayListCommand(currentUser.RequiredId, id, request.Name, request.Description, request.PictureIntentId, request.Visibility),
+                new UpdatePlayListCommand(currentUser.RequiredId, id, request.Name, request.Description, request.Visibility!.Value),
+                cancellationToken);
+
+            return result.ToHttpResult();
+        }
+
+        private static async Task<IResult> UpdatePlayListPicture(
+            IMediator mediator,
+            CurrentUser currentUser,
+            Guid id,
+            UpdatePlayListPictureRequest request,
+            CancellationToken cancellationToken)
+        {
+            var result = await mediator.Send(
+                new UpdatePlayListPictureCommand(currentUser.RequiredId, id, request.PictureIntentId),
                 cancellationToken);
 
             return result.ToHttpResult();

backend/Hosts/Musify.Api/Models/GenreParameter.cs

@@ -7,7 +7,7 @@ namespace Musify.Api.Models
     {
         public static bool TryParse(string? value, out GenreParameter result)
         {
-            if (Enum.TryParse<Genre>(value, ignoreCase: true, out var genre) && Enum.IsDefined(genre))
+            if (Enum.TryParse<Genre>(value, ignoreCase: true, out var genre) && genre != Genre.None && Enum.IsDefined(genre))
             {
                 result = new GenreParameter(genre);
                 return true;

backend/Hosts/Musify.Api/Validators/Albums/UpdateAlbumPictureRequestValidator.cs

@@ -0,0 +1,14 @@
+using FluentValidation;
+using Musify.Api.DataTransferObjects.Albums;
+
+namespace Musify.Api.Validators.Albums
+{
+    public sealed class UpdateAlbumPictureRequestValidator : AbstractValidator<UpdateAlbumPictureRequest>
+    {
+        public UpdateAlbumPictureRequestValidator()
+        {
+            RuleFor(x => x.PictureIntentId)
+                .NotEmpty();
+        }
+    }
+}

backend/Hosts/Musify.Api/Validators/PlayLists/UpdatePlayListPictureRequestValidator.cs

@@ -0,0 +1,14 @@
+using FluentValidation;
+using Musify.Api.DataTransferObjects.PlayLists;
+
+namespace Musify.Api.Validators.PlayLists
+{
+    public sealed class UpdatePlayListPictureRequestValidator : AbstractValidator<UpdatePlayListPictureRequest>
+    {
+        public UpdatePlayListPictureRequestValidator()
+        {
+            RuleFor(x => x.PictureIntentId)
+                .NotEmpty();
+        }
+    }
+}

backend/Hosts/Musify.Api/Validators/PlayLists/UpdatePlayListRequestValidator.cs

@@ -9,16 +9,14 @@ namespace Musify.Api.Validators.PlayLists
         {
             RuleFor(x => x.Name)
                 .NotEmpty()
-                .MaximumLength(Limits.PlayListName)
-                .When(x => x.Name != null);
+                .MaximumLength(Limits.PlayListName);
 
             RuleFor(x => x.Description)
-                .MaximumLength(Limits.Description)
-                .When(x => x.Description != null);
+                .MaximumLength(Limits.Description);
 
             RuleFor(x => x.Visibility)
-                .IsInEnum()
-                .When(x => x.Visibility != null);
+                .NotNull()
+                .IsInEnum();
         }
     }
 }

backend/Hosts/Musify.Api/Validators/Tracks/CreateTrackRequestValidator.cs

@@ -22,6 +22,11 @@ namespace Musify.Api.Validators.Tracks
                 .NotEmpty()
                 .WithMessage("At least one tag is required.");
 
+            RuleFor(x => x.Tags)
+                .Must(tags => !tags.Contains(Genre.None))
+                .When(x => x.Tags is { Count: > 0 })
+                .WithMessage("'None' is not a valid tag.");
+
             RuleFor(x => x.Tags)
                 .Must(tags => GenreCompatibility.FindConflicts(tags).Count == 0)
                 .When(x => x.Tags is { Count: > 0 })

backend/Tests/Musify.Api.Tests/Endpoints/AlbumEndpointsTests.cs

@@ -111,6 +111,37 @@ namespace Musify.Api.Tests.Endpoints
             Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
         }
 
+        [Fact]
+        public async Task UpdateAlbumPicture_NotTheOwner_ReturnsForbidden()
+        {
+            var owner = await CreateUserAsync();
+            var stranger = await CreateUserAsync();
+            var ownerClient = fixture.CreateAuthenticatedClient(owner);
+            var pictureIntentId = await CreatePictureIntentAsync(ownerClient);
+            var created = await (await ownerClient.PostAsJsonAsync("/albums", new CreateAlbumRequest("Owned", null, null, pictureIntentId), TestContext.Current.CancellationToken))
+                .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+
+            var response = await fixture.CreateAuthenticatedClient(stranger).PutAsJsonAsync(
+                $"/albums/{created!.Id}/picture", new UpdateAlbumPictureRequest(Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
+        }
+
+        [Fact]
+        public async Task UpdateAlbumPicture_EmptyIntent_ReturnsBadRequest()
+        {
+            var owner = await CreateUserAsync();
+            var ownerClient = fixture.CreateAuthenticatedClient(owner);
+            var pictureIntentId = await CreatePictureIntentAsync(ownerClient);
+            var created = await (await ownerClient.PostAsJsonAsync("/albums", new CreateAlbumRequest("Owned", null, null, pictureIntentId), TestContext.Current.CancellationToken))
+                .Content.ReadFromJsonAsync<AlbumApplicationResponse>(TestContext.Current.CancellationToken);
+
+            var response = await ownerClient.PutAsJsonAsync(
+                $"/albums/{created!.Id}/picture", new UpdateAlbumPictureRequest(Guid.Empty), TestContext.Current.CancellationToken);
+
+            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        }
+
         [Fact]
         public async Task DeleteAlbum_Owner_ReturnsNoContentAndAlbumIsGone()
         {

backend/Tests/Musify.Api.Tests/Endpoints/GenreEndpointsTests.cs

@@ -63,7 +63,7 @@ namespace Musify.Api.Tests.Endpoints
 
             Assert.Equal(HttpStatusCode.OK, response.StatusCode);
             var body = await response.Content.ReadFromJsonAsync<List<AvailableGenreResponse>>(JsonOptions, TestContext.Current.CancellationToken);
-            Assert.Equal(Enum.GetValues<Genre>().Length, body!.Count);
+            Assert.Equal(Enum.GetValues<Genre>().Count(genre => genre != Genre.None), body!.Count);
             Assert.Contains(Genre.Lofi, body.Single(g => g.Genre == Genre.Metal).IncompatibleWith);
         }
 

backend/Tests/Musify.Api.Tests/Endpoints/PlayListEndpointsTests.cs

@@ -96,7 +96,7 @@ namespace Musify.Api.Tests.Endpoints
             var playList = await CreatePlayListAsync(owner, PlayListVisibility.Public);
 
             var response = await fixture.CreateAuthenticatedClient(stranger).PutAsJsonAsync(
-                $"/playlists/{playList.Id}", new UpdatePlayListRequest("Hijacked", null, null), Ct);
+                $"/playlists/{playList.Id}", new UpdatePlayListRequest("Hijacked", null, PlayListVisibility.Public), Ct);
 
             Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
         }
@@ -120,13 +120,50 @@ namespace Musify.Api.Tests.Endpoints
             var playList = await CreatePlayListAsync(owner, PlayListVisibility.Private);
 
             var response = await fixture.CreateAuthenticatedClient(owner).PutAsJsonAsync(
-                $"/playlists/{playList.Id}", new UpdatePlayListRequest("Renamed", null, null), Ct);
+                $"/playlists/{playList.Id}", new UpdatePlayListRequest("Renamed", null, PlayListVisibility.Private), Ct);
 
             Assert.Equal(HttpStatusCode.OK, response.StatusCode);
             var body = await response.Content.ReadFromJsonAsync<PlayListApplicationResponse>(JsonOptions, Ct);
             Assert.Equal("Renamed", body!.Name);
         }
 
+        [Fact]
+        public async Task UpdatePlayList_MissingVisibility_ReturnsBadRequest()
+        {
+            var owner = await fixture.SeedUserAsync();
+            var playList = await CreatePlayListAsync(owner, PlayListVisibility.Public);
+
+            var response = await fixture.CreateAuthenticatedClient(owner).PutAsJsonAsync(
+                $"/playlists/{playList.Id}", new UpdatePlayListRequest("Renamed", null, null), Ct);
+
+            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        }
+
+        [Fact]
+        public async Task UpdatePlayListPicture_NotTheOwner_ReturnsForbidden()
+        {
+            var owner = await fixture.SeedUserAsync();
+            var stranger = await fixture.SeedUserAsync();
+            var playList = await CreatePlayListAsync(owner, PlayListVisibility.Public);
+
+            var response = await fixture.CreateAuthenticatedClient(stranger).PutAsJsonAsync(
+                $"/playlists/{playList.Id}/picture", new UpdatePlayListPictureRequest(Guid.NewGuid()), Ct);
+
+            Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
+        }
+
+        [Fact]
+        public async Task UpdatePlayListPicture_EmptyIntent_ReturnsBadRequest()
+        {
+            var owner = await fixture.SeedUserAsync();
+            var playList = await CreatePlayListAsync(owner, PlayListVisibility.Public);
+
+            var response = await fixture.CreateAuthenticatedClient(owner).PutAsJsonAsync(
+                $"/playlists/{playList.Id}/picture", new UpdatePlayListPictureRequest(Guid.Empty), Ct);
+
+            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+        }
+
         [Fact]
         public async Task GetPlayListById_NotAGuid_ReturnsNotFound()
         {

backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumCommandHandlerTests.cs

@@ -1,24 +1,15 @@
 using ErrorOr;
 using Musify.Application.Albums;
-using Musify.Application.Contracts;
-using Musify.Application.Services;
 using Musify.Application.Tests.TestSupport;
-using NSubstitute;
 using Xunit;
 
 namespace Musify.Application.Tests.Albums
 {
     public sealed class UpdateAlbumCommandHandlerTests : HandlerTestBase
     {
-        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-        private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
         private UpdateAlbumCommandHandler CreateHandler() => new(
-            eventBus,
             Database,
-            new UploadIntentValidator(Database, storageService, TestConfigurations.UploadIntent()),
-            NoOpLogger<UpdateAlbumCommandHandler>(),
-            TestConfigurations.Album());
+            NoOpLogger<UpdateAlbumCommandHandler>());
 
         [Fact]
         public async Task Handle_Owner_UpdatesTitleDescriptionAndReleaseYear()
@@ -27,7 +18,7 @@ namespace Musify.Application.Tests.Albums
             var album = TestEntities.Album(owner.Id, title: "Old Title", description: "Old", releaseYear: 2020);
             await SeedAsync(owner, album);
 
-            var command = new UpdateAlbumCommand(owner.Id, album.Id, "  New Title  ", "New description", 2025, null);
+            var command = new UpdateAlbumCommand(owner.Id, album.Id, "  New Title  ", "New description", 2025);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -42,32 +33,22 @@ namespace Musify.Application.Tests.Albums
         }
 
         [Fact]
-        public async Task Handle_ValidPictureIntent_UpdatesPictureAndPublishesSourceEvent()
+        public async Task Handle_BlankDescription_ClearsIt()
         {
-            storageService
-                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-                .Returns(new ObjectMetaData("image/webp", 1024));
-
             var owner = TestEntities.User();
-            var album = TestEntities.Album(owner.Id, title: "Old Title");
-            var intent = TestEntities.UploadIntent(owner.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.AlbumPicture, objectName: "new-cover.webp");
-            await SeedAsync(owner, album, intent);
+            var album = TestEntities.Album(owner.Id, title: "Title", description: "Old");
+            await SeedAsync(owner, album);
 
-            var command = new UpdateAlbumCommand(owner.Id, album.Id, "Old Title", null, null, intent.Id);
-
-            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
+            var result = await CreateHandler().Handle(new UpdateAlbumCommand(owner.Id, album.Id, "Title", "   ", null), TestContext.Current.CancellationToken);
 
             Assert.False(result.IsError);
-            var stored = await Database.Albums.FindAsync([album.Id], TestContext.Current.CancellationToken);
-            Assert.NotNull(stored);
-            Assert.Equal("new-cover.webp", stored.Pictures?.OriginalName);
-            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.UpdateAlbumPictureSourceEvent>(), Arg.Any<CancellationToken>());
+            Assert.Null(result.Value.Description);
         }
 
         [Fact]
         public async Task Handle_AlbumMissing_ReturnsNotFound()
         {
-            var command = new UpdateAlbumCommand(1, Guid.NewGuid(), "Title", null, null, null);
+            var command = new UpdateAlbumCommand(1, Guid.NewGuid(), "Title", null, null);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -82,7 +63,7 @@ namespace Musify.Application.Tests.Albums
             var album = TestEntities.Album(owner.Id);
             await SeedAsync(owner, stranger, album);
 
-            var command = new UpdateAlbumCommand(stranger.Id, album.Id, "Hijacked", null, null, null);
+            var command = new UpdateAlbumCommand(stranger.Id, album.Id, "Hijacked", null, null);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 

backend/Tests/Musify.Application.Tests/Albums/UpdateAlbumPictureCommandHandlerTests.cs

@@ -0,0 +1,69 @@
+using ErrorOr;
+using Musify.Application.Albums;
+using Musify.Application.Contracts;
+using Musify.Application.Services;
+using Musify.Application.Tests.TestSupport;
+using NSubstitute;
+using Xunit;
+
+namespace Musify.Application.Tests.Albums
+{
+    public sealed class UpdateAlbumPictureCommandHandlerTests : HandlerTestBase
+    {
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
+
+        private UpdateAlbumPictureCommandHandler CreateHandler() => new(
+            eventBus,
+            Database,
+            new UploadIntentValidator(Database, storageService, TestConfigurations.UploadIntent()),
+            NoOpLogger<UpdateAlbumPictureCommandHandler>(),
+            TestConfigurations.Album());
+
+        [Fact]
+        public async Task Handle_ValidPictureIntent_UpdatesPictureAndPublishesSourceEvent()
+        {
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 1024));
+
+            var owner = TestEntities.User();
+            var album = TestEntities.Album(owner.Id, title: "Keep Title", description: "Keep description", releaseYear: 2020);
+            var intent = TestEntities.UploadIntent(owner.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.AlbumPicture, objectName: "new-cover.webp");
+            await SeedAsync(owner, album, intent);
+
+            var result = await CreateHandler().Handle(new UpdateAlbumPictureCommand(owner.Id, album.Id, intent.Id), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal("Keep Title", result.Value.Title);
+            Assert.Equal("Keep description", result.Value.Description);
+            Assert.Equal(2020, result.Value.ReleaseYear);
+            var stored = await Database.Albums.FindAsync([album.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("new-cover.webp", stored.Pictures?.OriginalName);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.UpdateAlbumPictureSourceEvent>(), Arg.Any<CancellationToken>());
+        }
+
+        [Fact]
+        public async Task Handle_AlbumMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new UpdateAlbumPictureCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
+
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsForbidden()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var album = TestEntities.Album(owner.Id);
+            await SeedAsync(owner, stranger, album);
+
+            var result = await CreateHandler().Handle(new UpdateAlbumPictureCommand(stranger.Id, album.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+            await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.UpdateAlbumPictureSourceEvent>(), Arg.Any<CancellationToken>());
+        }
+    }
+}

backend/Tests/Musify.Application.Tests/Genres/GetAvailableGenresQueryHandlerTests.cs

@@ -11,11 +11,11 @@ namespace Musify.Application.Tests.Genres
             await new GetAvailableGenresQueryHandler().Handle(new GetAvailableGenresQuery(), TestContext.Current.CancellationToken);
 
         [Fact]
-        public async Task Handle_ReturnsEveryGenre()
+        public async Task Handle_ReturnsEveryGenreExceptNone()
         {
             var result = await RunAsync();
 
-            Assert.Equal(Enum.GetValues<Genre>(), result.Select(r => r.Genre));
+            Assert.Equal(Enum.GetValues<Genre>().Where(genre => genre != Genre.None), result.Select(r => r.Genre));
         }
 
         [Fact]

backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListCommandHandlerTests.cs

@@ -1,24 +1,15 @@
 using ErrorOr;
-using Musify.Application.Contracts;
 using Musify.Application.PlayLists;
-using Musify.Application.Services;
 using Musify.Application.Tests.TestSupport;
-using NSubstitute;
 using Xunit;
 
 namespace Musify.Application.Tests.PlayLists
 {
     public sealed class UpdatePlayListCommandHandlerTests : HandlerTestBase
     {
-        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
-        private readonly IStorageService storageService = Substitute.For<IStorageService>();
-
         private UpdatePlayListCommandHandler CreateHandler() => new(
-            eventBus,
             Database,
-            new UploadIntentValidator(Database, storageService, TestConfigurations.UploadIntent()),
-            NoOpLogger<UpdatePlayListCommandHandler>(),
-            TestConfigurations.PlayList());
+            NoOpLogger<UpdatePlayListCommandHandler>());
 
         [Fact]
         public async Task Handle_Owner_RenamesPlayList()
@@ -27,7 +18,7 @@ namespace Musify.Application.Tests.PlayLists
             var playList = TestEntities.PlayList(owner.Id, "Old Name");
             await SeedAsync(owner, playList);
 
-            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "New Name", null, null);
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "New Name", null, Musify.Domain.ValueObjects.PlayListVisibility.Private);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -38,7 +29,7 @@ namespace Musify.Application.Tests.PlayLists
         [Fact]
         public async Task Handle_PlayListMissing_ReturnsNotFound()
         {
-            var command = new UpdatePlayListCommand(1, Guid.NewGuid(), "New Name", null, null);
+            var command = new UpdatePlayListCommand(1, Guid.NewGuid(), "New Name", null, Musify.Domain.ValueObjects.PlayListVisibility.Private);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -53,7 +44,7 @@ namespace Musify.Application.Tests.PlayLists
             var playList = TestEntities.PlayList(owner.Id);
             await SeedAsync(owner, stranger, playList);
 
-            var command = new UpdatePlayListCommand(stranger.Id, playList.Id, "Hijacked", null, null);
+            var command = new UpdatePlayListCommand(stranger.Id, playList.Id, "Hijacked", null, Musify.Domain.ValueObjects.PlayListVisibility.Private);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -67,7 +58,7 @@ namespace Musify.Application.Tests.PlayLists
             var playList = TestEntities.PlayList(owner.Id);
             await SeedAsync(owner, playList);
 
-            var command = new UpdatePlayListCommand(owner.Id, playList.Id, null, null, null, Musify.Domain.ValueObjects.PlayListVisibility.Public);
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "Same Name", null, Musify.Domain.ValueObjects.PlayListVisibility.Public);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
@@ -76,59 +67,35 @@ namespace Musify.Application.Tests.PlayLists
         }
 
         [Fact]
-        public async Task Handle_NoVisibilitySpecified_LeavesItUnchanged()
+        public async Task Handle_ReplacesNameDescriptionAndVisibility()
         {
             var owner = TestEntities.User();
-            var playList = TestEntities.PlayList(owner.Id, visibility: Musify.Domain.ValueObjects.PlayListVisibility.Public);
+            var playList = TestEntities.PlayList(owner.Id, "Original Name", "Original description", visibility: Musify.Domain.ValueObjects.PlayListVisibility.Public);
             await SeedAsync(owner, playList);
 
-            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "New Name", null, null);
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "  New Name  ", "New description", Musify.Domain.ValueObjects.PlayListVisibility.Private);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
             Assert.False(result.IsError);
-            Assert.Equal(Musify.Domain.ValueObjects.PlayListVisibility.Public, result.Value.Visibility);
+            Assert.Equal("New Name", result.Value.Name);
+            Assert.Equal("New description", result.Value.Description);
+            Assert.Equal(Musify.Domain.ValueObjects.PlayListVisibility.Private, result.Value.Visibility);
         }
 
         [Fact]
-        public async Task Handle_BlankName_LeavesItUnchangedAndBlankDescriptionClearsIt()
+        public async Task Handle_MissingDescription_ClearsIt()
         {
             var owner = TestEntities.User();
             var playList = TestEntities.PlayList(owner.Id, "Original Name", "Original description");
             await SeedAsync(owner, playList);
 
-            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "   ", "   ", null);
+            var command = new UpdatePlayListCommand(owner.Id, playList.Id, "Original Name", null, Musify.Domain.ValueObjects.PlayListVisibility.Private);
 
             var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
 
             Assert.False(result.IsError);
-            Assert.Equal("Original Name", result.Value.Name);
             Assert.Null(result.Value.Description);
         }
-
-        [Fact]
-        public async Task Handle_PlayListWithoutPictures_ValidPictureIntent_SetsPictureAndPublishesSourceEvent()
-        {
-            storageService
-                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
-                .Returns(new ObjectMetaData("image/webp", 1024));
-
-            var owner = TestEntities.User();
-            var playList = TestEntities.PlayList(owner.Id);
-            playList.Pictures = null;
-            var intent = TestEntities.UploadIntent(owner.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.PlayListPicture, objectName: "new-cover.webp");
-            await SeedAsync(owner, playList, intent);
-
-            var command = new UpdatePlayListCommand(owner.Id, playList.Id, null, null, intent.Id);
-
-            var result = await CreateHandler().Handle(command, TestContext.Current.CancellationToken);
-
-            Assert.False(result.IsError);
-            Assert.Null(result.Value.SmallImageKeyName);
-            var stored = await Database.PlayLists.FindAsync([playList.Id], TestContext.Current.CancellationToken);
-            Assert.NotNull(stored);
-            Assert.Equal("new-cover.webp", stored.Pictures?.OriginalName);
-            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.UpdatePlayListPictureSourceEvent>(), Arg.Any<CancellationToken>());
-        }
     }
 }

backend/Tests/Musify.Application.Tests/PlayLists/UpdatePlayListPictureCommandHandlerTests.cs

@@ -0,0 +1,69 @@
+using ErrorOr;
+using Musify.Application.Contracts;
+using Musify.Application.PlayLists;
+using Musify.Application.Services;
+using Musify.Application.Tests.TestSupport;
+using NSubstitute;
+using Xunit;
+
+namespace Musify.Application.Tests.PlayLists
+{
+    public sealed class UpdatePlayListPictureCommandHandlerTests : HandlerTestBase
+    {
+        private readonly IEventBus eventBus = Substitute.For<IEventBus>();
+        private readonly IStorageService storageService = Substitute.For<IStorageService>();
+
+        private UpdatePlayListPictureCommandHandler CreateHandler() => new(
+            eventBus,
+            Database,
+            new UploadIntentValidator(Database, storageService, TestConfigurations.UploadIntent()),
+            NoOpLogger<UpdatePlayListPictureCommandHandler>(),
+            TestConfigurations.PlayList());
+
+        [Fact]
+        public async Task Handle_ValidPictureIntent_SetsPictureAndPublishesSourceEvent()
+        {
+            storageService
+                .HeadObjectAsync(Arg.Any<string>(), Arg.Any<string>(), Arg.Any<CancellationToken>())
+                .Returns(new ObjectMetaData("image/webp", 1024));
+
+            var owner = TestEntities.User();
+            var playList = TestEntities.PlayList(owner.Id, "Keep Name", "Keep description");
+            playList.Pictures = null;
+            var intent = TestEntities.UploadIntent(owner.Id, Musify.Domain.ValueObjects.UploadIntentPurpose.PlayListPicture, objectName: "new-cover.webp");
+            await SeedAsync(owner, playList, intent);
+
+            var result = await CreateHandler().Handle(new UpdatePlayListPictureCommand(owner.Id, playList.Id, intent.Id), TestContext.Current.CancellationToken);
+
+            Assert.False(result.IsError);
+            Assert.Equal("Keep Name", result.Value.Name);
+            Assert.Equal("Keep description", result.Value.Description);
+            var stored = await Database.PlayLists.FindAsync([playList.Id], TestContext.Current.CancellationToken);
+            Assert.NotNull(stored);
+            Assert.Equal("new-cover.webp", stored.Pictures?.OriginalName);
+            await eventBus.Received(1).PublishAsync(Arg.Any<Musify.Application.Events.UpdatePlayListPictureSourceEvent>(), Arg.Any<CancellationToken>());
+        }
+
+        [Fact]
+        public async Task Handle_PlayListMissing_ReturnsNotFound()
+        {
+            var result = await CreateHandler().Handle(new UpdatePlayListPictureCommand(1, Guid.NewGuid(), Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
+        }
+
+        [Fact]
+        public async Task Handle_NotOwner_ReturnsForbidden()
+        {
+            var owner = TestEntities.User(1, "owner");
+            var stranger = TestEntities.User(2, "stranger");
+            var playList = TestEntities.PlayList(owner.Id);
+            await SeedAsync(owner, stranger, playList);
+
+            var result = await CreateHandler().Handle(new UpdatePlayListPictureCommand(stranger.Id, playList.Id, Guid.NewGuid()), TestContext.Current.CancellationToken);
+
+            Assert.Equal(ErrorType.Forbidden, result.FirstError.Type);
+            await eventBus.DidNotReceive().PublishAsync(Arg.Any<Musify.Application.Events.UpdatePlayListPictureSourceEvent>(), Arg.Any<CancellationToken>());
+        }
+    }
+}