Musify/backend/Tests/Musify.Application.Tests/Mixes/GetMixByIdQueryHandlerTests.cs

using ErrorOr;
using Musify.Application.Mixes;
using Musify.Application.Tests.TestSupport;
using Xunit;

namespace Musify.Application.Tests.Mixes
{
    public sealed class GetMixByIdQueryHandlerTests : HandlerTestBase
    {
        private GetMixByIdQueryHandler CreateHandler() => new(Database);

        [Fact]
        public async Task Handle_OwnedMix_ReturnsItWithOrderedItems()
        {
            var owner = TestEntities.User();
            var firstTrack = TestEntities.Track(owner, "First");
            var secondTrack = TestEntities.Track(owner, "Second");
            var mix = TestEntities.Mix(owner.Id, "Discovery");
            var second = TestEntities.MixItem(mix.Id, secondTrack.Id, position: 1);
            var first = TestEntities.MixItem(mix.Id, firstTrack.Id, position: 0);
            await SeedAsync(owner, firstTrack, secondTrack, mix, second, first);

            var result = await CreateHandler().Handle(new GetMixByIdQuery(owner.Id, mix.Id), TestContext.Current.CancellationToken);

            Assert.False(result.IsError);
            Assert.Equal("Discovery", result.Value.Title);
            Assert.Equal(["First", "Second"], result.Value.Items.Select(item => item.Title));
        }

        [Fact]
        public async Task Handle_MixMissing_ReturnsNotFound()
        {
            var result = await CreateHandler().Handle(new GetMixByIdQuery(1, Guid.NewGuid()), TestContext.Current.CancellationToken);

            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
        }

        [Fact]
        public async Task Handle_MixBelongsToAnotherUser_ReturnsNotFound()
        {
            var owner = TestEntities.User(1, "owner");
            var mix = TestEntities.Mix(owner.Id);
            await SeedAsync(owner, mix);

            var result = await CreateHandler().Handle(new GetMixByIdQuery(2, mix.Id), TestContext.Current.CancellationToken);

            Assert.Equal(ErrorType.NotFound, result.FirstError.Type);
        }
    }
}