1 files changed, 130 insertions, 0 deletions
diff --git a/tests/Jellyfin.Server.Implementations.Tests/Item/ItemCountServiceTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Item/ItemCountServiceTests.cs
new file mode 100644
index 0000000000..0766ca8d1e
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+++ b/tests/Jellyfin.Server.Implementations.Tests/Item/ItemCountServiceTests.cs
@@ -0,0 +1,130 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Database.Implementations.Locking;
+using Jellyfin.Database.Providers.Sqlite;
+using Jellyfin.Server.Implementations.Item;
+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Persistence;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.Item;
+
+public sealed class ItemCountServiceTests : IDisposable
+{
+    private readonly SqliteConnection _connection;
+    private readonly DbContextOptions<JellyfinDbContext> _dbOptions;
+    private readonly IApplicationPaths _applicationPaths;
+    private readonly ItemCountService _service;
+
+    public ItemCountServiceTests()
+    {
+        _applicationPaths = new Mock<IApplicationPaths>().Object;
+
+        _connection = new SqliteConnection("Data Source=:memory:");
+        _connection.Open();
+
+        _dbOptions = new DbContextOptionsBuilder<JellyfinDbContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        using (var context = CreateDbContext())
+        {
+            context.Database.EnsureCreated();
+        }
+
+        var factory = new Mock<IDbContextFactory<JellyfinDbContext>>();
+        factory.Setup(f => f.CreateDbContext()).Returns(CreateDbContext);
+
+        _service = new ItemCountService(
+            factory.Object,
+            new Mock<IItemTypeLookup>().Object,
+            new Mock<IItemQueryHelpers>().Object);
+    }
+
+    public void Dispose()
+    {
+        _connection.Dispose();
+    }
+
+    [Fact]
+    public void GetChildCountBatch_LargeParentIdSet_DoesNotExceedSqliteVariableLimit()
+    {
+        var hierarchicalParentId = Guid.NewGuid();
+        var linkedParentId = Guid.NewGuid();
+
+        var hierarchicalChildId = Guid.NewGuid();
+        var linkedChildId1 = Guid.NewGuid();
+        var linkedChildId2 = Guid.NewGuid();
+
+        using (var context = CreateDbContext())
+        {
+            context.BaseItems.AddRange(
+                CreateItem(hierarchicalParentId),
+                CreateItem(linkedParentId),
+                CreateItem(hierarchicalChildId, hierarchicalParentId),
+                CreateItem(linkedChildId1),
+                CreateItem(linkedChildId2));
+
+            context.LinkedChildren.AddRange(
+                new LinkedChildEntity
+                {
+                    ParentId = linkedParentId,
+                    ChildId = linkedChildId1,
+                    ChildType = LinkedChildType.Manual,
+                    SortOrder = 0
+                },
+                new LinkedChildEntity
+                {
+                    ParentId = linkedParentId,
+                    ChildId = linkedChildId2,
+                    ChildType = LinkedChildType.Manual,
+                    SortOrder = 1
+                });
+
+            context.SaveChanges();
+        }
+
+        var parentIds = Enumerable.Range(0, 40_000)
+            .Select(_ => Guid.NewGuid())
+            .ToList();
+
+        parentIds.Add(hierarchicalParentId);
+        parentIds.Add(linkedParentId);
+
+        var result = _service.GetChildCountBatch(parentIds, null);
+
+        Assert.Equal(1, result[hierarchicalParentId]);
+        Assert.Equal(2, result[linkedParentId]);
+        Assert.Equal(parentIds.Count, result.Count);
+    }
+
+    private static BaseItemEntity CreateItem(Guid id, Guid? parentId = null)
+    {
+        return new BaseItemEntity
+        {
+            Id = id,
+            Type = "Folder",
+            ParentId = parentId,
+            IsFolder = true
+        };
+    }
+
+    private JellyfinDbContext CreateDbContext()
+    {
+        return new JellyfinDbContext(
+            _dbOptions,
+            NullLogger<JellyfinDbContext>.Instance,
+            new SqliteDatabaseProvider(
+                _applicationPaths,
+                NullLogger<SqliteDatabaseProvider>.Instance),
+            new NoLockBehavior(NullLogger<NoLockBehavior>.Instance));
+    }
+}