public void AddRange_ShouldAddPosts() { var posts = new List <IBlogPost> { new BlogPost { Title = "Hello, xUnit" }, new BlogPost { Title = "Hello, Tests" }, new BlogPost { Title = "Hello, World" }, }; _blogPostRepository.AddRange(posts); _inMemoryContext.ChangeTracker.Entries <BlogPost>().Should().HaveCount(posts.Count, "that's how many posts were added"); var entries = _inMemoryContext.ChangeTracker.Entries <BlogPost>(); entries.Select(e => e.State).Should().AllBeEquivalentTo(EntityState.Added, "we haven't commited the changes yet"); entries.Select(e => e.Entity).Should().BeEquivalentTo(posts, "they were the posts that were added"); }