Bean Validation seems weird with lazy fetch attribute.

[onacit]

Apologies. This issue may be just a question.

I have an entity with a lazy-fetch -to-one attribute.

@MappedSuperclass
abstract class MappedParent {

    @NotNull
    private String a;
}

@MappedSuperclass
abstract class MappedChild<PARENT extends MappedParent> {

    @NotNull
    @Basic(optional = false)
    @Column(name = "parent_id", nullable = false, insertable = true, updatable = false)
    private Long parentId;

    @Valid // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    @NotNull
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "parent_id", nullable = false, insertable = true, updatable = false)
    private <PARENT> parent;
}

@Entity
class Parent extends MappedParent {
}

@Entity
class Child extends MappedChild<Parent> {
}

When I, in my test code, select one and assure that the entity is valid, the framework (or library) tries to validate fields on.

@Transactional
@SpringBootTest
class SomeTest { 

    @Autowired
    private EntityManager entityManager;

    void () {
        final var found = entityManager.find(...)
        BeanValidationTestUtils.requireValid(selected); // <<<<<<<<<<<<<<<<<<<<<<<
    }

The BeanValidationTestUtils.requireValid(selected); looks like this. Nothing's special.

    public static <T> Set<ConstraintViolation<T>> validate(Validator validator, final T object,
                                                           final Class<?>... groups) {
        Objects.requireNonNull(validator, "validator is null");
        Objects.requireNonNull(object, "object is null");
        Objects.requireNonNull(groups, "groups is null");
        return validator.validate(object, groups);
    }

    public static <T> T requireValid(final Validator validator, final T object, final Class<?>... groups) {
        final var violations = validate(validator, object, groups);
        if (!violations.isEmpty()) {
            throw new ConstraintViolationException(violations);
        }
        return object;
    }

The moment just before validating the entity looks like this.

selected = (Child ...)
    parent_id = xx
    parent = (Parent@HibernateProxy@nnnn; a=<real, not-null>, b = <real; not-null>)
        $$_hibernate_interceptor
        a = null
        b = null

And the validation fails tries to validate parent.a.

parent.a: must not be null,

When I comment-out the @Valid annotation, leaving the @NotNull annotation, it passes.

    //@Valid // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    @NotNull
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "parent_id", nullable = false, insertable = true, updatable = false)
    private <PARENT> parent;

• I'm not sure this issue arose from the Hibernate
• and/or Hibernate-Validator

[schauder]

This has really nothing to do with Spring Data, but seems to be about Hibernate Validator.