test: golden tests for XMLTV guide output (refs #28)

Drive the real GetChannelGuideHandler against a Testably fake filesystem
(seeded channels.xml + per-channel fragments) and a SQLite-backed
IDbContextFactory with one visible + one ShowInEpg=false channel, then
snapshot ChannelGuide.ToXml(). Covers the {RequestBase}/{AccessTokenUri}
substitution (the #1 regression surface), etv:-tag stripping, hidden-channel
exclusion, and assembly — with/without access token and with a base URL.
The volatile ?v={mtime} cache-buster is normalized. Same [CallerFilePath]
Goldens + ETV_UPDATE_GOLDENS harness as the M3U goldens (#11).

Core.Tests now references ErsatzTV.Application (handler lives there).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ErsatzTV.Core.Tests/ErsatzTV.Core.Tests.csproj

@@ -26,6 +26,7 @@
     </ItemGroup>
 
     <ItemGroup>
+        <ProjectReference Include="..\ErsatzTV.Application\ErsatzTV.Application.csproj" />
         <ProjectReference Include="..\ErsatzTV.Core\ErsatzTV.Core.csproj" />
         <ProjectReference Include="..\ErsatzTV.Infrastructure.Sqlite\ErsatzTV.Infrastructure.Sqlite.csproj" />
         <ProjectReference Include="..\ErsatzTV.Infrastructure\ErsatzTV.Infrastructure.csproj" />

ErsatzTV.Core.Tests/Iptv/ChannelGuideGoldenTests.cs

@@ -0,0 +1,233 @@
+using System.Runtime.CompilerServices;
+using System.Text.RegularExpressions;
+using ErsatzTV.Application.Channels;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Metadata;
+using ErsatzTV.Core.Iptv;
+using ErsatzTV.Infrastructure;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.IO;
+using NSubstitute;
+using NUnit.Framework;
+using Shouldly;
+using MockFileSystem = Testably.Abstractions.Testing.MockFileSystem;
+
+namespace ErsatzTV.Core.Tests.Iptv;
+
+// Golden-file tests that lock the XMLTV guide output GetChannelGuideHandler produces — the surface
+// Jellyfin/clients consume for EPG + channel/programme artwork. The handler reads pre-built cache
+// fragments (channels.xml + {number}.xml), substitutes {RequestBase}/{AccessTokenUri}, strips
+// internal etv: tags, hides ShowInEpg=false channels, then assembles via ChannelGuide.ToXml().
+//
+// This is the XMLTV counterpart to ChannelPlaylistGoldenTests (#11) and, like it, is the regression
+// net for the {RequestBase} host substitution at the heart of #1. Goldens live under Goldens/ and are
+// regenerated via the Regenerate_goldens test or ETV_UPDATE_GOLDENS=1 — review the diff before committing.
+//
+// The goldens faithfully enshrine current behaviour, including the raw unescaped "&text=" ampersand the
+// real _channel.sbntxt template emits (technically not well-formed XML). That is why the comparison is
+// string equality rather than XDocument.Parse — a parse guard would throw on today's legitimate output.
+[TestFixture]
+public class ChannelGuideGoldenTests
+{
+    private const string Scheme = "https";
+    private const string Host = "tv.example.com";
+
+    // channels.xml is NOT filtered by ShowInEpg — every channel's <channel> def stays here; only the
+    // per-channel programme *data* fragment of a hidden channel is dropped. Channels 2 and 10 are visible,
+    // channel 3 is hidden. (2 vs 10 also proves ChannelGuide.ToXml orders fragments by DECIMAL, not string.)
+    private const string ChannelsXml =
+        """<channel id="C2.etv"><display-name>2 News</display-name><display-name>2</display-name><display-name>News</display-name><category lang="en">General</category><icon src="{RequestBase}/iptv/logos/news.jpg{AccessTokenUri}" /></channel><channel id="C10.etv"><display-name>10 Movies</display-name><display-name>10</display-name><display-name>Movies</display-name><icon src="{RequestBase}/iptv/logos/gen{AccessTokenUri}&text=Movies" /></channel><channel id="C3.etv"><display-name>3 Hidden</display-name><display-name>3</display-name><display-name>Hidden</display-name><icon src="{RequestBase}/iptv/logos/hidden.jpg{AccessTokenUri}" /></channel>""";
+
+    // Visible (channel 2) — exercises {RequestBase}/{AccessTokenUri} substitution on the programme artwork
+    // <icon> (which must SURVIVE) AND etv:-tag stripping. etv: nodes are the documented optional graphics-
+    // engine feature (paired like <etv:episode_number_key>…</etv:episode_number_key>); a trailing self-
+    // closing <etv:…/> exercises the regex's second alternative. Both must be gone from client output.
+    private const string Channel2Xml =
+        """<programme start="20260101080000 +0000" stop="20260101090000 +0000" channel="C2.etv"><title lang="en">Morning News</title><desc lang="en">Today's headlines.</desc><category lang="en">News</category><icon src="{RequestBase}/iptv/artwork/posters/abc.jpg{AccessTokenUri}" /><etv:episode_number_key>5</etv:episode_number_key><etv:marker /><previously-shown /></programme>""";
+
+    // Visible (channel 10) — uses an EXTERNAL icon URL with no placeholder, proving external URLs pass
+    // through verbatim. Its decimal key (10) must sort AFTER channel 2 despite string order putting "10" first.
+    private const string Channel10Xml =
+        """<programme start="20260101090000 +0000" stop="20260101110000 +0000" channel="C10.etv"><title lang="en">Matinee</title><desc lang="en">A film.</desc><category lang="en">Movie</category><icon src="https://cdn.example.com/movie.jpg" /></programme>""";
+
+    // Hidden (channel 3, ShowInEpg=false) — its programme data must NOT appear in the output.
+    private const string Channel3Xml =
+        """<programme start="20260101080000 +0000" stop="20260101090000 +0000" channel="C3.etv"><title lang="en">Hidden Show</title></programme>""";
+
+    private SqliteConnection _connection;
+    private IDbContextFactory<TvContext> _dbContextFactory;
+
+    [OneTimeSetUp]
+    public async Task SetUpDatabase()
+    {
+        // Shared in-memory SQLite: the connection must stay open for the DB to live across contexts.
+        // Foreign keys are disabled — we only read Channel.Number/ShowInEpg, so referential integrity
+        // (e.g. the FFmpegProfile FK) is irrelevant and would only complicate seeding.
+        _connection = new SqliteConnection("Data Source=:memory:;Foreign Keys=False");
+        await _connection.OpenAsync();
+
+        DbContextOptions<TvContext> options = new DbContextOptionsBuilder<TvContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        _dbContextFactory = new TestTvContextFactory(options);
+
+        await using TvContext context = _dbContextFactory.CreateDbContext();
+
+        // EnsureCreated builds the schema from the model directly — sufficient here and far cheaper than
+        // replaying every migration just to read two Channel columns.
+        await context.Database.EnsureCreatedAsync();
+        await context.Database.ExecuteSqlRawAsync("PRAGMA foreign_keys = OFF;");
+
+        context.Channels.Add(NewChannel("2", "News", showInEpg: true));
+        context.Channels.Add(NewChannel("10", "Movies", showInEpg: true));
+        context.Channels.Add(NewChannel("3", "Hidden", showInEpg: false));
+        await context.SaveChangesAsync();
+    }
+
+    [OneTimeTearDown]
+    public void TearDownDatabase() => _connection?.Dispose();
+
+    [Test]
+    public Task Guide_without_access_token() =>
+        Verify("guide-no-token.xml", new GetChannelGuide(Scheme, Host, BaseUrl: "", AccessToken: null));
+
+    [Test]
+    public Task Guide_with_access_token() =>
+        Verify("guide-with-token.xml", new GetChannelGuide(Scheme, Host, BaseUrl: "", AccessToken: "SECRET-TOKEN"));
+
+    [Test]
+    public Task Guide_with_base_url() =>
+        Verify("guide-base-url.xml", new GetChannelGuide(Scheme, Host, BaseUrl: "/etv", AccessToken: null));
+
+    // --- harness ---
+
+    private async Task Verify(string goldenName, GetChannelGuide request)
+    {
+        MockFileSystem fileSystem = BuildCacheFileSystem();
+
+        // ListFiles returns channels.xml too (the handler skips it via Contains("channels")) and in a
+        // deliberately non-decimal order, so the test proves ChannelGuide.ToXml re-sorts by decimal key.
+        var localFileSystem = Substitute.For<ILocalFileSystem>();
+        localFileSystem
+            .ListFiles(FileSystemLayout.ChannelGuideCacheFolder)
+            .Returns(new[]
+            {
+                FragmentPath(fileSystem, "channels.xml"),
+                FragmentPath(fileSystem, "10.xml"),
+                FragmentPath(fileSystem, "3.xml"),
+                FragmentPath(fileSystem, "2.xml")
+            });
+
+        var handler = new GetChannelGuideHandler(
+            _dbContextFactory,
+            new RecyclableMemoryStreamManager(),
+            fileSystem,
+            localFileSystem);
+
+        Either<BaseError, ChannelGuide> result = await handler.Handle(request, CancellationToken.None);
+
+        string actual = Normalize(
+            result.Match(
+                Right: guide => guide.ToXml(),
+                Left: error => throw new AssertionException($"Handler returned error: {error.Value}")));
+
+        string path = Path.Combine(GoldenDir(), goldenName);
+
+        if (Environment.GetEnvironmentVariable("ETV_UPDATE_GOLDENS") == "1")
+        {
+            Directory.CreateDirectory(GoldenDir());
+            await File.WriteAllTextAsync(path, actual);
+            Assert.Inconclusive($"Wrote golden '{goldenName}'. Review it and re-run to verify.");
+            return;
+        }
+
+        // A missing golden is a hard failure (not a silent skip) so an un-committed baseline can't pass CI.
+        File.Exists(path).ShouldBeTrue(
+            $"Missing golden '{goldenName}'. Run Regenerate_goldens (or ETV_UPDATE_GOLDENS=1) and commit it.");
+
+        string expected = Canonicalize(await File.ReadAllTextAsync(path));
+        actual.ShouldBe(expected);
+    }
+
+    [Test]
+    [Explicit("Regenerates all XMLTV goldens from current output; review the diff before committing.")]
+    public async Task Regenerate_goldens()
+    {
+        Environment.SetEnvironmentVariable("ETV_UPDATE_GOLDENS", "1");
+        try
+        {
+            foreach (Func<Task> regen in new Func<Task>[]
+                     {
+                         Guide_without_access_token, Guide_with_access_token, Guide_with_base_url
+                     })
+            {
+                try
+                {
+                    await regen();
+                }
+                catch (InconclusiveException)
+                {
+                    // expected — each Verify writes its golden then reports inconclusive
+                }
+            }
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("ETV_UPDATE_GOLDENS", null);
+        }
+    }
+
+    private static MockFileSystem BuildCacheFileSystem()
+    {
+        var fileSystem = new MockFileSystem();
+        fileSystem.Directory.CreateDirectory(FileSystemLayout.ChannelGuideCacheFolder);
+        fileSystem.File.WriteAllText(FragmentPath(fileSystem, "channels.xml"), ChannelsXml);
+        fileSystem.File.WriteAllText(FragmentPath(fileSystem, "2.xml"), Channel2Xml);
+        fileSystem.File.WriteAllText(FragmentPath(fileSystem, "10.xml"), Channel10Xml);
+        fileSystem.File.WriteAllText(FragmentPath(fileSystem, "3.xml"), Channel3Xml);
+        return fileSystem;
+    }
+
+    private static string FragmentPath(MockFileSystem fileSystem, string name) =>
+        fileSystem.Path.Combine(FileSystemLayout.ChannelGuideCacheFolder, name);
+
+    // The XMLTV cache-buster (?v={channels.xml last-write ticks}) is the only volatile token; pin it so
+    // the golden is deterministic. Then canonicalize to a single trailing newline (Canonicalize) so the
+    // golden satisfies .editorconfig insert_final_newline and a formatting pass can't break the test.
+    private static string Normalize(string xml) =>
+        Canonicalize(Regex.Replace(xml, @"\?v=\d+", "?v=MTIME"));
+
+    // Strip the UTF-8 BOM that XmlWriter emits as a preamble (the load-bearing strip — the golden files
+    // themselves have no BOM), normalize line endings, and force exactly one trailing newline.
+    private static string Canonicalize(string xml) =>
+        xml.TrimStart('').ReplaceLineEndings("\n").TrimEnd('\n') + "\n";
+
+    private static Channel NewChannel(string number, string name, bool showInEpg) =>
+        new(Guid.NewGuid())
+        {
+            Number = number,
+            Name = name,
+            Group = "ErsatzTV",
+            Categories = string.Empty,
+            StreamSelector = string.Empty,
+            PreferredAudioLanguageCode = string.Empty,
+            PreferredAudioTitle = string.Empty,
+            PreferredSubtitleLanguageCode = string.Empty,
+            MusicVideoCreditsTemplate = string.Empty,
+            ShowInEpg = showInEpg
+        };
+
+    private static string GoldenDir([CallerFilePath] string thisFile = "") =>
+        Path.Combine(Path.GetDirectoryName(thisFile) ?? ".", "Goldens");
+
+    private sealed class TestTvContextFactory(DbContextOptions<TvContext> options) : IDbContextFactory<TvContext>
+    {
+        public TvContext CreateDbContext() =>
+            new(options, NullLoggerFactory.Instance, new SlowQueryInterceptor(NullLogger<SlowQueryInterceptor>.Instance));
+    }
+}

ErsatzTV.Core.Tests/Iptv/Goldens/guide-base-url.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?><tv generator-info-name="ersatztv"><channel id="C2.etv"><display-name>2 News</display-name><display-name>2</display-name><display-name>News</display-name><category lang="en">General</category><icon src="https://tv.example.com/etv/iptv/logos/news.jpg?v=MTIME" /></channel><channel id="C10.etv"><display-name>10 Movies</display-name><display-name>10</display-name><display-name>Movies</display-name><icon src="https://tv.example.com/etv/iptv/logos/gen?v=MTIME&text=Movies" /></channel><channel id="C3.etv"><display-name>3 Hidden</display-name><display-name>3</display-name><display-name>Hidden</display-name><icon src="https://tv.example.com/etv/iptv/logos/hidden.jpg?v=MTIME" /></channel><programme start="20260101080000 +0000" stop="20260101090000 +0000" channel="C2.etv"><title lang="en">Morning News</title><desc lang="en">Today's headlines.</desc><category lang="en">News</category><icon src="https://tv.example.com/etv/iptv/artwork/posters/abc.jpg?v=MTIME" /><previously-shown /></programme><programme start="20260101090000 +0000" stop="20260101110000 +0000" channel="C10.etv"><title lang="en">Matinee</title><desc lang="en">A film.</desc><category lang="en">Movie</category><icon src="https://cdn.example.com/movie.jpg" /></programme></tv>

ErsatzTV.Core.Tests/Iptv/Goldens/guide-no-token.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?><tv generator-info-name="ersatztv"><channel id="C2.etv"><display-name>2 News</display-name><display-name>2</display-name><display-name>News</display-name><category lang="en">General</category><icon src="https://tv.example.com/iptv/logos/news.jpg?v=MTIME" /></channel><channel id="C10.etv"><display-name>10 Movies</display-name><display-name>10</display-name><display-name>Movies</display-name><icon src="https://tv.example.com/iptv/logos/gen?v=MTIME&text=Movies" /></channel><channel id="C3.etv"><display-name>3 Hidden</display-name><display-name>3</display-name><display-name>Hidden</display-name><icon src="https://tv.example.com/iptv/logos/hidden.jpg?v=MTIME" /></channel><programme start="20260101080000 +0000" stop="20260101090000 +0000" channel="C2.etv"><title lang="en">Morning News</title><desc lang="en">Today's headlines.</desc><category lang="en">News</category><icon src="https://tv.example.com/iptv/artwork/posters/abc.jpg?v=MTIME" /><previously-shown /></programme><programme start="20260101090000 +0000" stop="20260101110000 +0000" channel="C10.etv"><title lang="en">Matinee</title><desc lang="en">A film.</desc><category lang="en">Movie</category><icon src="https://cdn.example.com/movie.jpg" /></programme></tv>

ErsatzTV.Core.Tests/Iptv/Goldens/guide-with-token.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?><tv generator-info-name="ersatztv"><channel id="C2.etv"><display-name>2 News</display-name><display-name>2</display-name><display-name>News</display-name><category lang="en">General</category><icon src="https://tv.example.com/iptv/logos/news.jpg?v=MTIME&amp;access_token=SECRET-TOKEN" /></channel><channel id="C10.etv"><display-name>10 Movies</display-name><display-name>10</display-name><display-name>Movies</display-name><icon src="https://tv.example.com/iptv/logos/gen?v=MTIME&amp;access_token=SECRET-TOKEN&text=Movies" /></channel><channel id="C3.etv"><display-name>3 Hidden</display-name><display-name>3</display-name><display-name>Hidden</display-name><icon src="https://tv.example.com/iptv/logos/hidden.jpg?v=MTIME&amp;access_token=SECRET-TOKEN" /></channel><programme start="20260101080000 +0000" stop="20260101090000 +0000" channel="C2.etv"><title lang="en">Morning News</title><desc lang="en">Today's headlines.</desc><category lang="en">News</category><icon src="https://tv.example.com/iptv/artwork/posters/abc.jpg?v=MTIME&amp;access_token=SECRET-TOKEN" /><previously-shown /></programme><programme start="20260101090000 +0000" stop="20260101110000 +0000" channel="C10.etv"><title lang="en">Matinee</title><desc lang="en">A film.</desc><category lang="en">Movie</category><icon src="https://cdn.example.com/movie.jpg" /></programme></tv>