public async Task <Model.Order> UpdateOrder(Model.Order order)
{
var current = await _dbContext.Orders
.Include(o => o.OrderLines)
.SingleOrDefaultAsync(o => o.Id == order.Id);
if (current == default)
{
throw new ArgumentException($"Cannot update nonexistent order {order.Id}");
}
var orderDataContract = order.ToDataContract();
_dbContext.Entry(current).CurrentValues.SetValues(orderDataContract);
// Order lines are tracked entities so we need to manually sync the collection
_dbContext.SyncCollection(current, current.OrderLines, orderDataContract.OrderLines, s => s.Id);
await _dbContext.SaveChangesAsync();
return(current.ToModel());
}