Automatic reindex of #IndexedEmbedded field - hibernate-search

Question

As far I can understand from reading this part of the documentation of
https://docs.jboss.org/hibernate/search/6.0/reference/en-US/html_single/#mapper-orm-reindexing-basics
there's no automatic reindexing on #IndexedEmbedded fields that doesn't have a bidirectional mapping. Am I correct? And if so I'm curious to know what leaded to introduce this, because in Hibernate search automatic reindexing happened when updating a field in an #IndexedEmbedded field. Does this mean that now I'm responsible to update the index?
Here's an example of my use case which leads to a not updated index:
#Indexed(index = "foo_index")
#Entity
public class Foo {
private Long id;
#IndexedEmbedded
#ManyToOne(fetch = LAZY)
private Bar bar;
}
#Entity
public class Bar {
private Long id;
#GenericField
private String barFieldOne;
#GenericField
private String barFieldTwo;
}
Then let's say I retrieve the Foo from the db and change a bar field like this:
Foo foo = repository.findById(1);
foo.getBar().setBarFieldOne("newValue");
repository.save(foo);
This will not trigger index update of the foo index despite I'm working through the #Indexed object(Foo in our case). I have a lot of uni directional relations and I don't want to make them bidirectional because I don't need them and they can lead to performance problems. I understand that if I update the bar entity by itself it won't update the index but here I'm updating it through the main #Indexed entity and I expect the index to be updated.
This use case worked flawlessly in hibernate search 5 and in my honest opinion this is an important. Is there a way to make it work here, because this will make my life a lot easier.

Answer 1

You understood well, Hibernate Search cannot trigger reindexing when there's just an unidirectional association between the modified entity and the indexed entity.
There are plans to address that, maybe, one day, but that will still require some configuration: https://hibernate.atlassian.net/browse/HSEARCH-1937
This use case worked flawlessly in hibernate search 5 and in my honest opinion this is an important
I'm going to need a reproducer for that. I would be very, very surprised if you managed to make it work. If it worked, it was probably just a side-effect of something else: you disabled dirty checking, or you had a transient property on your entity that caused it to be reindexed every single time.
All we did in Search 6 was to make sure we throw an error when you try to use #IndexedEmbedded on an uni-directional association, and force you to explicitly disable automatic reindexing for that association.
It didn't work in Hibernate Search 5 either, but Hibernate Search 5 would ignore these problems silently and you would end up thinking it worked, but it did not.
So really, the only change is that you are now aware of the problem. It existed before.