Handling Generic Entities in Entity Framework's Change Tracker

I’m implementing a Domain-Driven Design (DDD) architecture and want to leverage strongly typed IDs for my entities. My base AggregateRoot class looks like this:

public abstract class AggregateRoot<TId>
    : Entity<TId>
    where TId : struct
{
    private readonly List<IDomainEvent> _domainEvents = [];

    // ...
}

Here’s an example entity:

public readonly record struct AuctionId(Guid Value);

public class Auction
    : AggregateRoot<AuctionId>
{
    // ...
}

I have a domain event dispatcher interceptor (PublishDomainEventsInterceptor) which I want to work generically with all aggregates:

internal sealed class PublishDomainEventsInterceptor 
    : SaveChangesInterceptor 
{
    // ...

    public async Task PublishDomainEvents(
        DbContext? context)
    {
        // ...

        // Problem: Need a generic way to handle strongly-typed IDs here
        var entities = context.ChangeTracker
            .Entries<AggregateRoot>() // Issue: Requires type argument
            .Where(e => e.Entity.DomainEvents.Any())
            .Select(e => e.Entity); 

        // ...
    }
}

How can I modify my PublishDomainEvents() method or related approach to make it work with AggregateRoot<TId> without knowing the specific TId type in advance? I want to maintain type safety and the benefits of strongly typed IDs.

Thank you in advance for your help, cheers! 🙂

>Solution :

Since your interceptor code does not actually need to use the strongly-typed Id the easiest option would be to introduce a non-generic interface for AggregateRoot<TId> to implement and use it:

public interface IAggregateRoot
{
   public IEnumerable<IDomainEvent> DomainEvents { get; }
}

public abstract class AggregateRoot<TId>
    : Entity<TId>, IAggregateRoot
    where TId : struct
{
    // ...
}

And usage:

var entities = context.ChangeTracker
    .Entries<IAggregateRoot>() 
    .Where(e => e.Entity.DomainEvents.Any())
    .Select(e => e.Entity);