Fetch a lazy association after using getReference doesn't work with Hibernate Reactive

[DavideD]

It's possible to reproduce it adding the following method to HibernateReactiveTestEndpointFetchLazy:

    @GET
    @Path("/getReferenceBooksWithMutiny/{authorId}")
    public Uni<Collection<Book>> getReferenceBooksWithMutiny(@PathParam("authorId") Integer authorId) {
        return Mutiny.fetch(mutinySession.getReference(Author.class, authorId).getBooks());
    }

and the test in HibernateReactiveFetchLazyTest

    @Test
    public void fetchAfterGetReferenceWithMutiny() {
        RestAssured.when()
                .post("/prepareDb")
                .then()
                .body(is("Neal Stephenson"));

        Response response = RestAssured.when()
                .get("/getReferenceBooksWithMutiny/567")
                .then()
                .extract().response();
        assertTitles(response, "Cryptonomicon", "Snow Crash");
    }

See my branch: https://github.com/DavideD/quarkus/tree/getreference

This will cause a Session is closed exception. Adding transaction won't cause any exception but it will return 0 results.

[quarkus-bot]

/cc @Sanne, @gavinking

[DavideD]

@gavinking Am I missing something or this should work?

[gavinking]

I think you need to fetch the entity first. getReference() usually returns a proxy.

[DavideD]

Do you mean like this?

    @GET
    @Path("/getReferenceBooksWithMutiny/{authorId}")
    public Uni<Collection<Book>> getReferenceBooksWithMutiny(@PathParam("authorId") Integer authorId) {
        return Mutiny.fetch(mutinySession.getReference(Author.class, authorId))
                .chain(author -> Mutiny.fetch(author.getBooks()));
    }

[gavinking]

yeah, like that, not like what I wrote :-)

[DavideD]

:-)

Sadly, it still doesn't work and gives Session already closed.

[gavinking]

Does it work in a plain HR test?

[DavideD]

I will try to test this exact case, but we have several tests in ReferenceTest similar to this one.

[gavinking]

well we probably do need to add a test with a detached object like the example I added to the docs.

[DavideD]

I think we already cover these cases in Hibernate reactive.
See ReferenceTest:

• testDetachedEntityReference
• testDetachedProxyReference

[DavideD]

I haven't verified it, but I suspect this issue is related to this one on Hibernate Reactive: hibernate/hibernate-reactive#975