YesSql.Tests.CoreTests.ShouldJoinReduceIndex C# (CSharp) Method

        public async Task ShouldJoinReduceIndex()
        {
            _store.RegisterIndexes<ArticleIndexProvider>();
            _store.RegisterIndexes<PublishedArticleIndexProvider>();

            using (var session = _store.CreateSession())
            {
                var dates = new[]
                {
                    new DateTime(2011, 11, 1), // published
                    new DateTime(2011, 11, 2), // not published
                    new DateTime(2011, 11, 3), // published
                    new DateTime(2011, 11, 4), // not published
                    new DateTime(2011, 11, 1), // published
                    new DateTime(2011, 11, 2), // not published
                    new DateTime(2011, 11, 3), // published
                    new DateTime(2011, 11, 1), // not published
                    new DateTime(2011, 11, 2), // published
                    new DateTime(2011, 11, 1) // not published
                };

                var articles = dates.Select((x, i) => new Article
                {
                    IsPublished = i % 2 == 0, // half are published
                    PublishedUtc = x
                });

                foreach (var article in articles)
                {
                    session.Save(article);
                }

            }

            using (var session = _store.CreateSession())
            {
                Assert.Equal(4, await session.QueryIndexAsync<ArticlesByDay>().Count());

                Assert.Equal(4, await session.QueryAsync().For<Article>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 1).DayOfYear).Count());
                Assert.Equal(3, await session.QueryAsync().For<Article>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 2).DayOfYear).Count());
                Assert.Equal(2, await session.QueryAsync().For<Article>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 3).DayOfYear).Count());
                Assert.Equal(1, await session.QueryAsync().For<Article>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 4).DayOfYear).Count());

                Assert.Equal(2, await session.QueryAsync().For<Article>().With<PublishedArticle>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 1).DayOfYear).Count());
                Assert.Equal(1, await session.QueryAsync().For<Article>().With<PublishedArticle>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 2).DayOfYear).Count());
                Assert.Equal(2, await session.QueryAsync().For<Article>().With<PublishedArticle>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 3).DayOfYear).Count());
                Assert.Equal(0, await session.QueryAsync().For<Article>().With<PublishedArticle>().With<ArticlesByDay>(x => x.DayOfYear == new DateTime(2011, 11, 4).DayOfYear).Count());
            }
        }