@Test
    @Order(4)
    public void ensureSessionIsPropagatedOnReactiveTransactions() {
        getApp().given()
                .contentType(ContentType.JSON)
                .post("hibernate/books/pablo/suntzu")
                .then()
                .body(is(""))
                .statusCode(HttpStatus.SC_CREATED);
    }

@Path("/hibernate")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class GroundedEndpoint {

    Mutiny.SessionFactory factory;

    ...

    @POST
    @Path("books/{authorName}/{name}")
    public Uni<Response> createBook(String authorName, String name) {
        return factory.withTransaction((session, transaction) -> {
            Author author = new Author();
            author.setName(authorName);
            return session.persist(author)
                    .map(nothing -> session.getReference(author).getId())
                    .map(authorId -> {
                        Book book = new Book();
                        book.setAuthor(authorId);
                        book.setTitle(name);
                        return book;
                    })
                    .flatMap(session::persist);
        })
                .map(nothing -> Response.status(Response.Status.CREATED))
                .onFailure().recoverWithItem(error -> Response.status(Response.Status.BAD_REQUEST).entity(error.getMessage()))
                .map(Response.ResponseBuilder::build);
    }
}

[ERROR] Tests run: 4, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 78.008 s <<< FAILURE! - in io.quarkus.ts.reactive.OracleDatabaseIT
[ERROR] ensureSessionIsPropagatedOnReactiveTransactions  Time elapsed: 1.107 s  <<< FAILURE!
java.lang.AssertionError: 
1 expectation failed.
Response body doesn't match expectation.
Expected: is ""
  Actual: Multiple exceptions caught:
	[Exception 0] io.vertx.core.VertxException: Error : 1453, Position : 0, Sql = SET TRANSACTION ISOLATION LEVEL READ COMMITTED, OriginalSql = SET TRANSACTION ISOLATION LEVEL READ COMMITTED, Error Msg = ORA-01453: SET TRANSACTION must be first statement of transaction

	[Exception 1] java.lang.NullPointerException

	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
	at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:72)
	at org.codehaus.groovy.reflection.CachedConstructor.doConstructorInvoke(CachedConstructor.java:59)
	at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrap.callConstructor(ConstructorSite.java:84)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstructor(CallSiteArray.java:59)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:263)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:277)
	at io.restassured.internal.ResponseSpecificationImpl$HamcrestAssertionClosure.validate(ResponseSpecificationImpl.groovy:493)
	at io.restassured.internal.ResponseSpecificationImpl$HamcrestAssertionClosure$validate$1.call(Unknown Source)
	at io.restassured.internal.ResponseSpecificationImpl.validateResponseIfRequired(ResponseSpecificationImpl.groovy:674)
        ...