DomainObjectReader bypasses value object invariants [DATAREST-1191]

Patrik Mihalcin opened DATAREST-1191 and commented

I have Validity value object:

@Value
@Embeddable
public class Validity {
    public static final String VALID_FROM_CANT_BE_NULL = "Valid from can't be null";
    public static final String VALID_TO_CANT_BE_BEFORE_VALID_FROM = "Valid to can't be before valid from";

    @Column(name = "VALID_FROM", nullable = false)
    private final LocalDate validFrom;

    @Column(name = "VALID_TO")
    private final LocalDate validTo;

    public Validity(LocalDate validFrom, LocalDate validTo) {
        checkValidity(validFrom, validTo);

        this.validFrom = validFrom;
        this.validTo = validTo;
    }

    private void checkValidity(LocalDate validFrom, LocalDate validTo) {
        Assert.notNull(validFrom, VALID_FROM_CANT_BE_NULL);
        if (validTo != null) {
            Assert.isTrue(validFrom.isBefore(validTo) || validFrom.isEqual(validTo), VALID_TO_CANT_BE_BEFORE_VALID_FROM);
        }
    }
}

When I want to create new Validity using REST API, I can issue POST request, but I have to tell Jackson to use Validity constructor using following Jackson customization:

abstract static class ValidityMixin {
	@JsonCreator
	public ValidityMixin(@JsonProperty(required = true) LocalDate validFrom,
							LocalDate validTo) {
	}
}

When I want to update existing Validity object and I issue PATCH request, DomainObjectReader used by JsonPatchHandler doesn't go through constructor and it sets fields using reflection and system ends up with Validity object with broken invariant.

Why is that?

No further details from DATAREST-1191