public async Task Update_Book_Isbn() { var book = await BookHelpers.CreateValidBookWithAllProperties(); var repository = new BookRepository(_fixture.Context); (await repository.ExistsAsync(book.Id)).Should().BeTrue(); var sut = await repository.GetAsync(book.Id); var bookId = sut.Id; sut.Should().NotBeNull(); sut.Isbn.Should().Be("9781566199094"); await BookHelpers.UpdateIsbn(sut.Id, "000224585X"); await _fixture.Context.Entry(sut).ReloadAsync(); sut.Isbn.Should().Be("000224585X"); sut.Id.Should().Be(bookId); }