1 files changed, 155 insertions, 0 deletions
diff --git a/tests/Jellyfin.Server.Implementations.Tests/Library/MovieSimilarItemsProviderTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Library/MovieSimilarItemsProviderTests.cs
new file mode 100644
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+++ b/tests/Jellyfin.Server.Implementations.Tests/Library/MovieSimilarItemsProviderTests.cs
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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Emby.Server.Implementations.Data;
+using Emby.Server.Implementations.Library.SimilarItems;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Server.Implementations.Tests.Item;
+using MediaBrowser.Controller.Configuration;
+using MediaBrowser.Controller.Dto;
+using MediaBrowser.Controller.Entities.Movies;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Model.Configuration;
+using Moq;
+using Xunit;
+using BaseItemKind = Jellyfin.Data.Enums.BaseItemKind;
+
+namespace Jellyfin.Server.Implementations.Tests.Library;
+
+/// <summary>
+/// Covers how <see cref="MovieSimilarItemsProvider"/> treats alternate versions: they share their
+/// primary's genres, tags, studios and people, so they score like it and must not be offered as
+/// something similar - neither as another copy of a recommendation nor as a match for the source.
+/// </summary>
+public sealed class MovieSimilarItemsProviderTests : SqliteDbTestFixture
+{
+    private readonly MovieSimilarItemsProvider _provider;
+    private readonly User _user = new("test", "auth-provider", "reset-provider");
+    private readonly string _movieTypeName;
+
+    private readonly Guid _source = Guid.NewGuid();
+    private readonly Guid _sourceAlternate = Guid.NewGuid();
+    private readonly Guid _similar = Guid.NewGuid();
+    private readonly Guid _similarAlternate = Guid.NewGuid();
+    private readonly Guid _unrelated = Guid.NewGuid();
+
+    public MovieSimilarItemsProviderTests()
+    {
+        var itemTypeLookup = new ItemTypeLookup();
+        _movieTypeName = itemTypeLookup.BaseItemKindNames[BaseItemKind.Movie]!;
+
+        using (var context = CreateDbContext())
+        {
+            Seed(context);
+        }
+
+        var serverConfigurationManager = new Mock<IServerConfigurationManager>();
+        serverConfigurationManager.Setup(c => c.Configuration).Returns(new ServerConfiguration());
+
+        _provider = new MovieSimilarItemsProvider(
+            CreateDbContextFactory(),
+            CreateBaseItemRepository(itemTypeLookup),
+            serverConfigurationManager.Object,
+            new Mock<ILibraryManager>().Object);
+    }
+
+    [Fact]
+    public async Task GetSimilarItems_ReturnsThePrimaryAndNeitherVersionOfTheSource()
+    {
+        var items = await GetSimilarItemsAsync().ConfigureAwait(true);
+
+        Assert.Equal([_similar], items);
+    }
+
+    [Fact]
+    public async Task GetSimilarItems_DoesNotOfferAnAlternateVersionOfAMatch()
+    {
+        var items = await GetSimilarItemsAsync().ConfigureAwait(true);
+
+        Assert.DoesNotContain(_similarAlternate, items);
+    }
+
+    [Fact]
+    public async Task GetSimilarItems_DoesNotOfferTheSourcesOwnOtherVersion()
+    {
+        var items = await GetSimilarItemsAsync().ConfigureAwait(true);
+
+        Assert.DoesNotContain(_sourceAlternate, items);
+    }
+
+    private async Task<List<Guid>> GetSimilarItemsAsync()
+    {
+        var results = await _provider.GetSimilarItemsAsync(
+            new Movie { Id = _source, Name = "Source" },
+            new SimilarItemsQuery { User = _user, Limit = 10, DtoOptions = new DtoOptions() },
+            CancellationToken.None).ConfigureAwait(false);
+
+        return results.Select(i => i.Id).ToList();
+    }
+
+    private void Seed(JellyfinDbContext context)
+    {
+        // One shared genre, so every movie but the unrelated one scores against the source.
+        var shared = CreateItemValue("Action", "action");
+        var other = CreateItemValue("Comedy", "comedy");
+
+        var source = AddMovie(context, _source, "Source", primaryVersionId: null);
+        var sourceAlternate = AddMovie(context, _sourceAlternate, "Source 4K", primaryVersionId: _source);
+        var similar = AddMovie(context, _similar, "Similar", primaryVersionId: null);
+        var similarAlternate = AddMovie(context, _similarAlternate, "Similar 4K", primaryVersionId: _similar);
+        var unrelated = AddMovie(context, _unrelated, "Unrelated", primaryVersionId: null);
+
+        context.Users.Add(_user);
+        context.ItemValues.AddRange(shared, other);
+        context.ItemValuesMap.AddRange(
+            CreateMap(source, shared),
+            CreateMap(sourceAlternate, shared),
+            CreateMap(similar, shared),
+            CreateMap(similarAlternate, shared),
+            CreateMap(unrelated, other));
+
+        context.SaveChanges();
+    }
+
+    private BaseItemEntity AddMovie(JellyfinDbContext context, Guid id, string name, Guid? primaryVersionId)
+    {
+        var item = new BaseItemEntity
+        {
+            Id = id,
+            Type = _movieTypeName,
+            Name = name,
+            SortName = name,
+            MediaType = "Video",
+            IsMovie = true,
+            IsFolder = false,
+            IsVirtualItem = false,
+            // An alternate presents under its primary's key, which is what collapses the group in listings.
+            PresentationUniqueKey = (primaryVersionId ?? id).ToString("N"),
+            PrimaryVersionId = primaryVersionId
+        };
+
+        context.BaseItems.Add(item);
+        return item;
+    }
+
+    private static ItemValue CreateItemValue(string value, string cleanValue)
+        => new()
+        {
+            ItemValueId = Guid.NewGuid(),
+            Type = ItemValueType.Genre,
+            Value = value,
+            CleanValue = cleanValue
+        };
+
+    private static ItemValueMap CreateMap(BaseItemEntity item, ItemValue itemValue)
+        => new()
+        {
+            ItemId = item.Id,
+            ItemValueId = itemValue.ItemValueId,
+            Item = item,
+            ItemValue = itemValue
+        };
+}