Persistable implementation not carrying is-new state forward for immutable types

[odrotbohm]

When aggregates are designed to be effectively immutable, e.g. by providing with…(…) methods, the state of the synthetic is-new flag introduced via the ByteBuddy plugin is not transferred to the fresh instance created as the user code doesn't know about it.

@AllArgsConstructor // Gets this.__jMolecules_isNew = true; added
class Sample {

  private final UUID id;
  private final Status status;

  // Generated:
  // private @Transient boolean __jMolecules_isNew = true; <- generated

  Sample(Status status) {

    this.id = UUID.randomUUID();
    this.status = status;
    
    // Generated:
    // this.__jMolecules_isNew = true; 
  }

  Sample withStatus(Status status) {
    return new Sample(this.id, status);
  }

  // Generated:
  // @PrePersist
  // @PostLoad
  // void markNotNew() {
  //   this.__jMolecules_isNew = false;
  // }
}

Imagine a Sample instance created and persisted. It'll end up with the is-new flag set to false. Calling withStatus(…) however will result the new instance that is effectively considered the same aggregate (same identifier) but has the is-new flag reset to true.

A first attempt to solve the problem might be to attach to the wither convention and post process object instances returned for those to transfer the flag if the type returned is the current type or a specialized flavor of it.