gistfile1.cs

[Fact]
		public void CanQueryMapReduceIndex_WithUpdates()
		{
			using (var store = NewDocumentStore())
			{
				store.DatabaseCommands.PutIndex("TagCloud",
												new IndexDefinition
												{
													Map =
														@"
from post in docs.Posts 
from Tag in post.Tags
select new { Tag, Count = 1 }",

													Reduce =
														@"
from result in results
group result by result.Tag into g
select new { Tag = g.Key, Count = g.Sum(x => (long)x.Count) }"
												});

				using (var session = store.OpenSession())
				{
					session.Store(new Post
					{
						PostedAt = DateTime.Now,
						Tags = new List<string> { "C#", "Programming", "NoSql" }
					});
					session.Store(new Post
					{
						PostedAt = DateTime.Now,
						Tags = new List<string> { "Database", "NoSql" }
					});
					session.SaveChanges();

					var tagAndCounts = session.Query<TagAndCount>("TagCloud").WaitForNonStaleResults()
					.ToArray();

					Assert.Equal(1, tagAndCounts.Single(x => x.Tag == "C#").Count);
					Assert.Equal(1, tagAndCounts.Single(x => x.Tag == "Database").Count);
					Assert.Equal(2, tagAndCounts.Single(x => x.Tag == "NoSql").Count);
					Assert.Equal(1, tagAndCounts.Single(x => x.Tag == "Programming").Count);
		
					session.Store(new Post
					{
						PostedAt = DateTime.Now,
						Tags = new List<string> { "C#", "Programming", "NoSql" }
					});
					session.Store(new Post
					{
						PostedAt = DateTime.Now,
						Tags = new List<string> { "Database", "NoSql" }
					});
					session.SaveChanges();

					tagAndCounts = session.Query<TagAndCount>("TagCloud").WaitForNonStaleResults()
						.ToArray();

					Assert.Equal(2, tagAndCounts.Single(x => x.Tag == "C#").Count);
					Assert.Equal(2, tagAndCounts.Single(x => x.Tag == "Database").Count);
					Assert.Equal(4, tagAndCounts.Single(x => x.Tag == "NoSql").Count);
					Assert.Equal(2, tagAndCounts.Single(x => x.Tag == "Programming").Count);
				}
			}
		}