public void GetAll_ShouldReturnAllPosts() { var posts = new List <BlogPost> { new BlogPost { BlogPostId = Guid.NewGuid() }, new BlogPost { BlogPostId = Guid.NewGuid() }, new BlogPost { BlogPostId = Guid.NewGuid() }, new BlogPost { BlogPostId = Guid.NewGuid() } }; _inMemoryContext.Posts.AddRange(posts); _inMemoryContext.SaveChanges(); var expected = posts.Select(p => (IBlogPost)p).ToList(); _blogPostRepository.GetAll().Result.Should().BeEquivalentTo(expected, "because we expect to get all the posts stored in the database"); }