jellyfin/tests/Jellyfin.Server.Implementations.Tests/Library/MediaStreamSelectorTests.cs

using System;
using Emby.Server.Implementations.Library;
using MediaBrowser.Model.Entities;
using Xunit;

namespace Jellyfin.Server.Implementations.Tests.Library;

public class MediaStreamSelectorTests
{
    [Theory]
    [InlineData(true)]
    [InlineData(false)]
    public void GetDefaultAudioStreamIndex_EmptyStreams_Null(bool preferDefaultTrack)
    {
        Assert.Null(MediaStreamSelector.GetDefaultAudioStreamIndex(Array.Empty<MediaStream>(), Array.Empty<string>(), preferDefaultTrack));
    }

    [Theory]
    [InlineData(new string[0], false, 1)]
    [InlineData(new string[0], true, 1)]
    [InlineData(new[] { "eng" }, false, 2)]
    [InlineData(new[] { "eng" }, true, 1)]
    [InlineData(new[] { "eng", "fre" }, false, 2)]
    [InlineData(new[] { "fre", "eng" }, false, 1)]
    [InlineData(new[] { "eng", "fre" }, true, 1)]
    public void GetDefaultAudioStreamIndex_PreferredLanguage_SelectsCorrect(string[] preferredLanguages, bool preferDefaultTrack, int expectedIndex)
    {
        var streams = new MediaStream[]
        {
            new()
            {
                Index = 1,
                Language = "fre",
                IsDefault = true
            },
            new()
            {
                Index = 2,
                Language = "eng",
                IsDefault = false
            }
        };

        Assert.Equal(expectedIndex, MediaStreamSelector.GetDefaultAudioStreamIndex(streams, preferredLanguages, preferDefaultTrack));
    }
}