Musify/backend/Tests/Musify.Application.Tests/Likes/GetLikedTracksQueryHandlerTests.cs

using Musify.Application.Likes;
using Musify.Application.Tests.TestSupport;
using Musify.Domain.Entities;
using Xunit;

namespace Musify.Application.Tests.Likes
{
    public sealed class GetLikedTracksQueryHandlerTests : HandlerTestBase
    {
        private GetLikedTracksQueryHandler CreateHandler() => new(Database);

        [Fact]
        public async Task Handle_MultipleLikes_ReturnsMostRecentFirst()
        {
            var owner = TestEntities.User();
            var older = TestEntities.Track(owner, "Older like");
            var newer = TestEntities.Track(owner, "Newer like");
            await SeedAsync(
                owner, older, newer,
                new TrackLike { UserId = owner.Id, TrackId = older.Id, CreatedAt = DateTime.UtcNow.AddMinutes(-10) },
                new TrackLike { UserId = owner.Id, TrackId = newer.Id, CreatedAt = DateTime.UtcNow });

            var result = await CreateHandler().Handle(new GetLikedTracksQuery(owner.Id, 1, 10), TestContext.Current.CancellationToken);
            Assert.Equal(["Newer like", "Older like"], result.Items.Select(track => track.Title));
        }

        [Fact]
        public async Task Handle_NoLikes_ReturnsEmpty()
        {
            var owner = TestEntities.User();
            await SeedAsync(owner);

            var result = await CreateHandler().Handle(new GetLikedTracksQuery(owner.Id, 1, 10), TestContext.Current.CancellationToken);
            Assert.Empty(result.Items);
        }

        [Fact]
        public async Task Handle_OtherUsersLikes_AreExcluded()
        {
            var owner = TestEntities.User(1, "owner");
            var stranger = TestEntities.User(2, "stranger");
            var track = TestEntities.Track(owner);
            await SeedAsync(owner, stranger, track, new TrackLike { UserId = stranger.Id, TrackId = track.Id });

            var result = await CreateHandler().Handle(new GetLikedTracksQuery(owner.Id, 1, 10), TestContext.Current.CancellationToken);
            Assert.Empty(result.Items);
        }
    }
}