1 files changed, 110 insertions, 0 deletions
diff --git a/tests/Jellyfin.Server.Implementations.Tests/Library/MediaSourceManagerTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Library/MediaSourceManagerTests.cs
index facdb2bc2e..b788fb304e 100644
--- a/tests/Jellyfin.Server.Implementations.Tests/Library/MediaSourceManagerTests.cs
+++ b/tests/Jellyfin.Server.Implementations.Tests/Library/MediaSourceManagerTests.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using AutoFixture;
 using AutoFixture.AutoMoq;
 using Castle.Components.DictionaryAdapter;
@@ -7,6 +9,8 @@ using Emby.Server.Implementations.Library;
 using Jellyfin.Database.Implementations.Entities;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.LiveTv;
+using MediaBrowser.Controller.MediaSegments;
 using MediaBrowser.Model.Dto;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.Globalization;
@@ -144,5 +148,111 @@ namespace Jellyfin.Server.Implementations.Tests.Library
             _mediaSourceManager.SetDefaultAudioAndSubtitleStreamIndices(_item, mediaInfo, _user);
             Assert.Equal(expectedIndex, mediaInfo.DefaultAudioStreamIndex);
         }
+
+        [Fact]
+        public void GetStaticMediaSources_PrimaryQueried_PopulatesPerVersionPositionsAndDefaultsToMostRecent()
+        {
+            var (primary, alt1, alt2) = SetupVersionGroup();
+            SetupUserDataBatch(new Dictionary<Guid, UserItemData>
+            {
+                [alt1.Id] = new UserItemData { Key = "alt1", PlaybackPositionTicks = 10, LastPlayedDate = new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc) },
+                [alt2.Id] = new UserItemData { Key = "alt2", PlaybackPositionTicks = 20, LastPlayedDate = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc) }
+            });
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false, _user);
+
+            // Each version carries its own resume point; the primary has none.
+            Assert.Equal((long?)10, sources.First(s => s.Id == alt1.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Equal((long?)20, sources.First(s => s.Id == alt2.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Null(sources.First(s => s.Id == primary.Id.ToString("N")).PlaybackPositionTicks);
+
+            // The most recently played version is the default source, so resuming plays the right file.
+            Assert.Equal(alt2.Id.ToString("N"), sources[0].Id);
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_AlternateQueried_KeepsOwnSourceFirst()
+        {
+            var (primary, alt1, alt2) = SetupVersionGroup();
+            SetupUserDataBatch(new Dictionary<Guid, UserItemData>
+            {
+                [alt2.Id] = new UserItemData { Key = "alt2", PlaybackPositionTicks = 20, LastPlayedDate = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc) }
+            });
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(alt1, false, _user);
+
+            // An explicitly opened version keeps its own source first, even when a sibling was
+            // played more recently, but the sibling's resume point is still populated.
+            Assert.Equal(alt1.Id.ToString("N"), sources[0].Id);
+            Assert.Equal((long?)20, sources.First(s => s.Id == alt2.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Equal(3, sources.Count);
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_NoProgress_KeepsQueriedItemFirst()
+        {
+            var (primary, _, _) = SetupVersionGroup();
+            SetupUserDataBatch([]);
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false, _user);
+
+            Assert.Equal(primary.Id.ToString("N"), sources[0].Id);
+            Assert.All(sources, s => Assert.Null(s.PlaybackPositionTicks));
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_NoUser_DoesNotTouchUserData()
+        {
+            var (primary, _, _) = SetupVersionGroup();
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false);
+
+            Assert.Equal(primary.Id.ToString("N"), sources[0].Id);
+            _mockUserDataManager.Verify(x => x.GetUserDataBatch(It.IsAny<IReadOnlyList<BaseItem>>(), It.IsAny<User>()), Times.Never);
+        }
+
+        private void SetupUserDataBatch(Dictionary<Guid, UserItemData> userData)
+        {
+            _mockUserDataManager
+                .Setup(x => x.GetUserDataBatch(It.IsAny<IReadOnlyList<BaseItem>>(), It.IsAny<User>()))
+                .Returns((IReadOnlyList<BaseItem> items, User _) => items
+                    .Where(i => userData.ContainsKey(i.Id))
+                    .ToDictionary(i => i.Id, i => userData[i.Id]));
+        }
+
+        private static (Video Primary, Video Alt1, Video Alt2) SetupVersionGroup()
+        {
+            var primary = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie.mkv" };
+            var alt1 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 1080p.mkv", PrimaryVersionId = primary.Id };
+            var alt2 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 4K.mkv", PrimaryVersionId = primary.Id };
+
+            // BaseItem.GetMediaSources runs against the static service locators.
+            var mediaSourceManager = new Mock<IMediaSourceManager>();
+            mediaSourceManager.Setup(x => x.GetPathProtocol(It.IsAny<string>())).Returns(MediaProtocol.File);
+            mediaSourceManager.Setup(x => x.GetMediaStreams(It.IsAny<Guid>())).Returns(new List<MediaStream>());
+            mediaSourceManager.Setup(x => x.GetMediaAttachments(It.IsAny<Guid>())).Returns(new List<MediaAttachment>());
+
+            var segmentManager = new Mock<IMediaSegmentManager>();
+            segmentManager.Setup(x => x.IsTypeSupported(It.IsAny<BaseItem>())).Returns(false);
+
+            var libraryManager = new Mock<ILibraryManager>();
+            libraryManager.Setup(x => x.GetLinkedAlternateVersions(It.IsAny<Video>())).Returns(Array.Empty<Video>());
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(primary)).Returns(new[] { alt1.Id, alt2.Id });
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt1)).Returns(Array.Empty<Guid>());
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt2)).Returns(Array.Empty<Guid>());
+            libraryManager.Setup(x => x.GetItemById(primary.Id)).Returns(primary);
+            libraryManager.Setup(x => x.GetItemById(alt1.Id)).Returns(alt1);
+            libraryManager.Setup(x => x.GetItemById(alt2.Id)).Returns(alt2);
+
+            var recordingsManager = new Mock<IRecordingsManager>();
+            recordingsManager.Setup(x => x.GetActiveRecordingInfo(It.IsAny<string>())).Returns((ActiveRecordingInfo?)null);
+
+            BaseItem.MediaSegmentManager = segmentManager.Object;
+            BaseItem.MediaSourceManager = mediaSourceManager.Object;
+            BaseItem.LibraryManager = libraryManager.Object;
+            Video.RecordingsManager = recordingsManager.Object;
+
+            return (primary, alt1, alt2);
+        }
     }
 }