1 files changed, 81 insertions, 1 deletions

diff --git a/tests/Jellyfin.Api.Tests/Controllers/ItemUpdateControllerTests.cs b/tests/Jellyfin.Api.Tests/Controllers/ItemUpdateControllerTests.cs
index 1a91efe4f2..7b37550e29 100644
--- a/tests/Jellyfin.Api.Tests/Controllers/ItemUpdateControllerTests.cs
+++ b/tests/Jellyfin.Api.Tests/Controllers/ItemUpdateControllerTests.cs
@@ -4,9 +4,11 @@ using Jellyfin.Api.Controllers;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Movies;
+using MediaBrowser.Controller.Entities.TV;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Dto;
+using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.Globalization;
 using MediaBrowser.Model.IO;
 using Moq;
@@ -14,12 +16,21 @@ using Xunit;
 
 namespace Jellyfin.Api.Tests.Controllers;
 
-public class ItemUpdateControllerTests
+[Collection("LibraryManagerTests")]
+public sealed class ItemUpdateControllerTests : IDisposable
 {
     private readonly ItemUpdateController _subject;
+    private readonly ILibraryManager? _previousLibraryManager;
+    private readonly ILocalizationManager? _previousLocalizationManager;
 
     public ItemUpdateControllerTests()
     {
+        // Children are scored and saved through BaseItem's process-wide statics; restored in Dispose.
+        _previousLibraryManager = BaseItem.LibraryManager;
+        _previousLocalizationManager = BaseItem.LocalizationManager;
+        BaseItem.LibraryManager = Mock.Of<ILibraryManager>();
+        BaseItem.LocalizationManager = Mock.Of<ILocalizationManager>();
+
         _subject = new ItemUpdateController(
             Mock.Of<IFileSystem>(),
             Mock.Of<ILibraryManager>(),
@@ -70,6 +81,75 @@ public class ItemUpdateControllerTests
         Assert.Equal("tt1234567", movie.ProviderIds["Imdb"]);
     }
 
+    public void Dispose()
+    {
+        BaseItem.LibraryManager = _previousLibraryManager!;
+        BaseItem.LocalizationManager = _previousLocalizationManager!;
+    }
+
+    [Fact]
+    public async Task UpdateItem_SeriesRatingUnchanged_KeepsEpisodeRatings()
+    {
+        // Regression test for https://github.com/jellyfin/jellyfin/issues/18241
+        var (series, season, episodes) = CreateSeries("TV-PG", "TV-PG", "TV-14", null);
+
+        await InvokeUpdateItem(new BaseItemDto { Overview = "New overview", OfficialRating = "TV-PG" }, series);
+
+        Assert.Equal("TV-PG", season.OfficialRating);
+        Assert.Equal("TV-14", episodes[1].OfficialRating);
+        Assert.Null(episodes[2].OfficialRating);
+    }
+
+    [Fact]
+    public async Task UpdateItem_SeriesRatingChanged_PropagatesOnlyToChildrenFollowingIt()
+    {
+        var (series, season, episodes) = CreateSeries("TV-PG", "TV-PG", "TV-14", null);
+        var locked = new Episode { OfficialRating = "TV-PG", PreferredMetadataCountryCode = "us", LockedFields = [MetadataField.OfficialRating] };
+        season.Children = [.. episodes, locked];
+
+        await InvokeUpdateItem(new BaseItemDto { OfficialRating = "TV-MA" }, series);
+
+        Assert.Equal("TV-MA", season.OfficialRating);
+        Assert.Equal("TV-MA", episodes[0].OfficialRating);
+        Assert.Equal("TV-14", episodes[1].OfficialRating);
+        Assert.Equal("TV-MA", episodes[2].OfficialRating);
+        Assert.Equal("TV-PG", locked.OfficialRating);
+    }
+
+    [Fact]
+    public async Task UpdateItem_SeriesCustomRatingChanged_PropagatesIt()
+    {
+        var (series, season, episodes) = CreateSeries("TV-PG", "TV-PG", "TV-14", null);
+        episodes[0].CustomRating = "TV-Y";
+
+        await InvokeUpdateItem(new BaseItemDto { OfficialRating = "TV-PG", CustomRating = "XXX" }, series);
+
+        Assert.Equal("XXX", season.CustomRating);
+        Assert.Equal("TV-Y", episodes[0].CustomRating);
+        Assert.Equal("XXX", episodes[1].CustomRating);
+        Assert.Equal("TV-14", episodes[1].OfficialRating);
+    }
+
+    [Fact]
+    public async Task UpdateItem_SeasonRatingChanged_KeepsEpisodesWithTheirOwnRating()
+    {
+        var (_, season, episodes) = CreateSeries("TV-PG", "TV-PG", "TV-14", null);
+
+        await InvokeUpdateItem(new BaseItemDto { OfficialRating = "TV-MA" }, season);
+
+        Assert.Equal("TV-MA", episodes[0].OfficialRating);
+        Assert.Equal("TV-14", episodes[1].OfficialRating);
+        Assert.Equal("TV-MA", episodes[2].OfficialRating);
+    }
+
+    private static (Series Series, Season Season, Episode[] Episodes) CreateSeries(string seriesRating, params string?[] episodeRatings)
+    {
+        var episodes = Array.ConvertAll(episodeRatings, r => new Episode { OfficialRating = r, PreferredMetadataCountryCode = "us" });
+        var season = new Season { OfficialRating = seriesRating, PreferredMetadataCountryCode = "us", Children = episodes };
+        var series = new Series { OfficialRating = seriesRating, PreferredMetadataCountryCode = "us", Children = [season] };
+        return (series, season, episodes);
+    }
+
     private Task InvokeUpdateItem(BaseItemDto request, BaseItem item)
     {
         return _subject.UpdateItem(request, item);