Retrofit more tests on slicer

[jeremydmiller]

See this lifted from Marten:

public class multi_stream_projections: DaemonContext
{
    public multi_stream_projections(ITestOutputHelper output): base(output)
    {
    }

    [Fact]
    public void lifecycle_is_async_by_default()
    {
        new DayProjection().Lifecycle.ShouldBe(ProjectionLifecycle.Async);
    }

    [Fact]
    public async Task splicing_events()
    {
        NumberOfStreams = 10;
        await PublishMultiThreaded(3);

        var allEvents = await theSession.Events.QueryAllRawEvents().ToListAsync();

        var slicer = new DayProjection().Slicer;

        var slices = await slicer.SliceAsyncEvents(theSession, allEvents.ToList());

        foreach (var slice in slices.SelectMany(x => x.Slices).ToArray())
        {
            var events = slice.Events();
            events.All(x => x.Data is IDayEvent || x.Data is Movement || x.Data is Stop).ShouldBeTrue();
            events.Select(x => x.Data).OfType<IDayEvent>().All(x => x.Day == slice.Id)
                .ShouldBeTrue();

            var travels = events.OfType<Event<Travel>>().ToArray();
            foreach (var travel in travels)
            {
                var index = events.As<List<IEvent>>().IndexOf(travel);

                for (var i = 0; i < travel.Data.Stops.Count; i++)
                {
                    events.ElementAt(index + i + 1).Data.ShouldBeSameAs(travel.Data.Stops[i]);
                }
            }
        }

        slices.ShouldNotBeNull();
    }