ExecuteWithGraph: InvalidOperationException with model with subtype within owned type

[fretje]

I've tried to make a minimal reproducible sample. The crux of the issue (I think) is that my model has a subtype (an ICollection<Email>) within an owned type (ContactMethods), and somehow the foreign keys (ContactMethodsCustomerId) of the Email entities don't get filled before sending them to sqlbulkcopy?

using EFCore.BulkExtensions;
using Microsoft.EntityFrameworkCore;

var connectionString = "Server=localhost;Database=BulkExtensionsTestDb;Trusted_Connection=True;TrustServerCertificate=True;MultipleActiveResultSets=true;";
using var context = new MyDbContext(new DbContextOptionsBuilder().UseSqlServer(connectionString).Options);

context.Database.EnsureCreated();

var bulkConfig = new BulkConfig { IncludeGraph = true, CalculateStats = true };
Customer[] entities = [
    new()
    {
        CustomerId = "test1",
        ContactMethods = new()
        {
            HomePhone = "homephone1",
            EmailAdresses = [
                new Email() { Address = "email1", Type = "emailtype1" },
                new Email() { Address = "email2", Type = "emailtype2" },
            ]
        },
    }
];

await context.BulkInsertOrUpdateAsync(entities, bulkConfig);


public class MyDbContext(DbContextOptions opts) : DbContext(opts)
{
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Customer>(c => 
            c.OwnsOne(x => x.ContactMethods, 
                cm => cm.OwnsMany(y => y.EmailAdresses)));
    }
}

public class Customer
{
    public string CustomerId { get; set; } = default!;
    public ContactMethods ContactMethods { get; set; } = default!;
}

public class ContactMethods
{
    public string HomePhone { get; set; } = default!;
    public ICollection<Email> EmailAdresses { get; set; } = default!;
}

public class Email
{
    public string Address { get; set; } = default!;
    public string Type { get; set; } = default!;
}

This is the Exception which is thrown on await context.BulkInsertOrUpdateAsync(entities, bulkConfig);

System.InvalidOperationException
  HResult=0x80131509
  Message=Column 'ContactMethodsCustomerId' does not allow DBNull.Value.
  Source=Microsoft.Data.SqlClient
  StackTrace:
   at Microsoft.Data.SqlClient.SqlBulkCopy.ConvertValue(Object value, _SqlMetaData metadata, Boolean isNull, Boolean& isSqlType, Boolean& coercedToDataFeed)
   at Microsoft.Data.SqlClient.SqlBulkCopy.ReadWriteColumnValueAsync(Int32 col)
   at Microsoft.Data.SqlClient.SqlBulkCopy.CopyColumnsAsync(Int32 col, TaskCompletionSource`1 source)
   at Microsoft.Data.SqlClient.SqlBulkCopy.CopyRowsAsync(Int32 rowsSoFar, Int32 totalRows, CancellationToken cts, TaskCompletionSource`1 source)
   at Microsoft.Data.SqlClient.SqlBulkCopy.CopyBatchesAsyncContinued(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource`1 source)
   at Microsoft.Data.SqlClient.SqlBulkCopy.CopyBatchesAsync(BulkCopySimpleResultSet internalResults, String updateBulkCommandText, CancellationToken cts, TaskCompletionSource`1 source)
   at Microsoft.Data.SqlClient.SqlBulkCopy.WriteToServerInternalRestContinuedAsync(BulkCopySimpleResultSet internalResults, CancellationToken cts, TaskCompletionSource`1 source)
--- End of stack trace from previous location ---
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<InsertAsync>d__6`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<InsertAsync>d__6`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<InsertAsync>d__6`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<InsertAsync>d__5`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<MergeAsync>d__9`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<MergeAsync>d__9`1.MoveNext()
   at EFCore.BulkExtensions.SqlAdapters.SqlServer.SqlServerAdapter.<MergeAsync>d__8`1.MoveNext()
   at EFCore.BulkExtensions.SqlBulkOperation.<MergeAsync>d__5`1.MoveNext()
   at EFCore.BulkExtensions.DbContextBulkTransactionGraphUtil.<ExecuteWithGraphAsync>d__2.MoveNext()
   at EFCore.BulkExtensions.DbContextBulkTransactionGraphUtil.<ExecuteWithGraphAsync>d__2.MoveNext()
   at EFCore.BulkExtensions.DbContextBulkTransactionGraphUtil.<ExecuteWithGraphAsync>d__1.MoveNext()
   at EFCore.BulkExtensions.DbContextBulkTransaction.<ExecuteAsync>d__1`1.MoveNext()
   at Program.<<Main>$>d__0.MoveNext() in C:\Projects\test\ConsoleAppBulkExtensions\ConsoleAppBulkExtensions\Program.cs:line 25