Linq projection - unfriendly error message

[andyci]

Example entity:

public class Customer {
    public virtual Contact BillingContact { get; set; }
}

public class Contact {
    public virtual DateTime DateOfBirth { get; set; }
}

(from c in Session.Query<Customer>()
select new {
DateOfBirth = c.BillingContact.DateOfBirth
}).ToList();

Because LINQ sees the projected property as being of type DateTime, if the BillingContact property is null then we get a NullReferenceException which tells us nothing about which property is actually causing the problem. When you have 20+ fields in your projection then it is extremely painful to track down which of the properties is causing this error. I know we could just do (DateTime?)c.BillingContact.DateOfBirth but this isn't always practical and doesn't help, e.g. in the case where a complex property that was originally non-nullable later becomes nullable.

I'm thinking of making a change to the codebase to perhaps include the property name that is failing in the exception details. Does this seem like a reasonable change to make? I can see there will be a bit of work required since, at the moment, only the column index is accessible from the method that is throwing.

[hazzik]

Does this seem like a reasonable change to make?

Yes