public void DeleteBookScenarioBasic() { var options = new DbContextOptionsBuilder <BooksDbContext>() .UseInMemoryDatabase(databaseName: "DeleteBookScenarioBasic") .Options; // Insert seed data into the database using one instance of the context using (var ctx = new BooksDbContext(options)) { ctx.Database.EnsureCreated(); } // Use a clean instance of the context to run the test using (var ctx = new BooksDbContext(options)) { var repo = new BooksRepository(ctx); repo.DeleteBookAsync(3).Wait(); } // Use a clean instance of the context to run the test using (var ctx = new BooksDbContext(options)) { var repo = new BooksRepository(ctx); var books = repo.RetrieveBooksAsync().Result; Assert.Equal(4, books.Count()); } }