save() doesn't return updated entity if immutable properties used for @id or @version [DATACOUCH-625]

[spring-projects-issues]

jpringle opened DATACOUCH-625 and commented

I've been experimenting with an optimal combination of Lombok annotations, generated identity fields and version support.

Along the way, I've found that if the identity field or the version field are immutable (and thus with() methods used for property updates) then the property updates applied during save() are not propagated back to the returned object instance.

This appears to be due to expecting the updates to be applied to the passed in object instance, but "withers" return new object instances which are dropped along the way.

Ie, in ReactiveUpsertByIdOperationSupport.one():

    @Override    public Mono<T> one(T object) {
      return Mono.just(object).flatMap(o -> {
        CouchbaseDocument converted = template.support().encodeEntity(o);
        return template.getCollection(collection).reactive()
            .upsert(converted.getId(),
                    converted.export(),
                    buildUpsertOptions()).map(result -> {
              template.support().applyUpdatedCas(object, result.cas());
              return o;
            });
      }).onErrorMap(throwable -> {
    ...
    }

the object instance "o" (or "object") is never updated with the generated Id value or the result of "applyUpdatedCas()" if the property accessor results in a new object instance (as is the case with "wither" and final properties)

---

Referenced from: pull request #274

Backported to: 4.0.5 (Neumann SR5)

[spring-projects-issues]

Michael Reiche commented

Would not making those fields immutable be a solution?

[spring-projects-issues]

jpringle commented

well sure, but then you can't follow the documentation's advice for modeling objects.

Ie - it seems the contract being offered by the higher-level spring data mapping constructs is "you can (and should) use immutable objects, just make sure to provide wither methods for id and version properties", but spring data couchbase's implementation falls short.

In the spirit of "it just works if I follow the instructions and advice", I'd expect to be able to use this simple immutable data class w/o gymnastics:

 

@Value
@Document
public class Person {
  @Id @With String id;
  @Version @With long version;
  @Field String fName;
  @Field String lName;
}

[spring-projects-issues]

Michael Reiche commented

fixed 
template.support().applyUpdatedCas
and calling code, added
template.support().applyUpdatedId