Bulk operations does not require transaction to be performed.

[alex-kulakov]

Look at the following operation

using(var session = Domain.OpenSession()) {
   _ = session.Query.Insert(() => new TestEntity(session) { Name = "The Awesome Name" });
}

This code will work for some reason. I would expect an exception telling that transaction is required.

There is strange part in Operation

protected void EnsureTransactionIsStarted()
    {
      var accessor = QueryProvider.Session.Services.Demand<DirectSqlAccessor>();
      var notUsed = accessor.Transaction;
    }

I'm pretty sure this part relies on some check within the accessor.Transaction property.
This property checked transaction existence long ago:

public DbTransaction Transaction {
  get {
    TryStartTransaction();
    return service.Transaction;
  }
}

private void TryStartTransaction()
{
  if (Session.Transaction!=null)
    Session.EnsureTransactionIsStarted();
}

but now there is no check so I think check for transaction should be recovered but within extension to force user to open TransactionScope. Otherwise, insert will be executed in auto-commit transactions. I have a feeling that this is not how it should work.