1 files changed, 89 insertions, 0 deletions
diff --git a/tests/Jellyfin.Controller.Tests/Library/VersionResumeDataTests.cs b/tests/Jellyfin.Controller.Tests/Library/VersionResumeDataTests.cs
new file mode 100644
index 0000000000..7d87d5ee92
--- /dev/null
+++ b/tests/Jellyfin.Controller.Tests/Library/VersionResumeDataTests.cs
@@ -0,0 +1,89 @@
+using System;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Model.Dto;
+using Xunit;
+
+namespace Jellyfin.Controller.Tests.Library;
+
+public class VersionResumeDataTests
+{
+    [Fact]
+    public void ApplyTo_CompletedOtherVersion_PropagatesCompletionAndClearsStaleResume()
+    {
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", PlaybackPositionTicks = 0, Played = true, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", PlaybackPositionTicks = 1, Played = false, PlayedPercentage = 50 };
+
+        resume.ApplyTo(dto);
+
+        // Completion state propagates to the primary...
+        Assert.True(dto.Played);
+        Assert.Equal(lastPlayed, dto.LastPlayedDate);
+
+        // ...and because the movie was finished on a different version, the primary's own stale resume bar is cleared.
+        Assert.Equal(0, dto.PlaybackPositionTicks);
+        Assert.Null(dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_PrimaryOwnProgress_KeepsResumePosition()
+    {
+        var primaryId = Guid.NewGuid();
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+
+        // The winning version is the primary itself (e.g. rewatching): its resume bar must survive.
+        var resume = new VersionResumeData(
+            primaryId,
+            new UserItemData { Key = "primary", PlaybackPositionTicks = 5, Played = true, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = primaryId, Key = "primary", PlaybackPositionTicks = 5, Played = true, PlayedPercentage = 20 };
+
+        resume.ApplyTo(dto);
+
+        Assert.True(dto.Played);
+        Assert.Equal(5, dto.PlaybackPositionTicks);
+        Assert.Equal(20, dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_InProgressOtherVersion_KeepsPrimaryResumePosition()
+    {
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+
+        // A different version that is in-progress (not finished) must not clear the primary's position.
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", PlaybackPositionTicks = 25, Played = false, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", PlaybackPositionTicks = 1, Played = false, PlayedPercentage = 50 };
+
+        resume.ApplyTo(dto);
+
+        Assert.False(dto.Played);
+        Assert.Equal(1, dto.PlaybackPositionTicks);
+        Assert.Equal(50, dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_DoesNotUnsetExistingPlayedOrRegressLastPlayed()
+    {
+        var primaryLastPlayed = new DateTime(2026, 1, 5, 0, 0, 0, DateTimeKind.Utc);
+        var versionLastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", Played = false, LastPlayedDate = versionLastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", Played = true, LastPlayedDate = primaryLastPlayed };
+
+        resume.ApplyTo(dto);
+
+        // A not-yet-completed version must not clear the primary's own completion, and the more recent
+        // LastPlayedDate is kept.
+        Assert.True(dto.Played);
+        Assert.Equal(primaryLastPlayed, dto.LastPlayedDate);
+    }
+}