public async Task Update_Book_Formats()
{
var book = await BookHelpers.CreateValidBookWithAllProperties();
var repository = new BookRepository(_fixture.Context);
(await repository.ExistsAsync(book.Id)).Should().BeTrue();
var sut = await repository.LoadAsync(book.Id);
var bookId = sut.Id;
sut.Should().NotBeNull();
sut.Formats.Count.Should().Be(2);
var format1 = await FormatHelpers.CreateValidFormat();
var format2 = await FormatHelpers.CreateValidFormat();
var formats = new List <Format> {
format1, format2
};
await BookHelpers.UpdateFormats(sut.Id, formats);
sut = await repository.LoadAsync(book.Id);
await _fixture.Context.Entry(sut).ReloadAsync();
sut.Formats.Count.Should().Be(4);
sut.Id.Should().Be(bookId);
}