Hibernate-validator 6: Weird behavior of the #Max annotation with a BigDecimal set on a Number field - hibernate-validator

Question

I think I might have found an oddity in hibernate-validator 6.0.15.Final. It used to work with the version 5.4.2.Final.
Here is a test example:
import lombok.Data;
import org.junit.Test;
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import javax.validation.constraints.Max;
import java.math.BigDecimal;
import java.util.Set;
import static org.assertj.core.api.Assertions.assertThat;
public class ValidTest {
#Data
static class ClassToValidate{
public ClassToValidate() {
failingNumber = new BigDecimal("1.001");
failingBigDecimal = new BigDecimal("1.001");
passingNumber = new BigDecimal("0.001");
passingBigDecimal = new BigDecimal("0.001");
}
#Max(1)
private Number failingNumber;
#Max(1)
private BigDecimal failingBigDecimal;
#Max(1)
private Number passingNumber;
#Max(1)
private BigDecimal passingBigDecimal;
}
#Test
public void test(){
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<ClassToValidate>> violations = validator
.validate(new ClassToValidate());
for (ConstraintViolation<ClassToValidate> violation : violations) {
System.out.println(violation);
}
assertThat(violations).hasSize(2);
}
}
The BigDecimal stored in a Number field will not trigger a constraint exception even though it is bigger than 1. And a bigdecimal such as 2.xxx would.
It feels like the validator does not (anymore) take into account the numbers after the comma in BigDecimals objects stored in a Number.

Answer 1

Hum, you're right, we have a bug here: when you use a Number as the declared type as you did, we end up comparing longs. It should be an easy fix though.
I saw you filled https://hibernate.atlassian.net/browse/HV-1699 , we will give you updates there.
I will make a release as soon as we have a fix as it's definitely a bad one.

Answer 2

With Java Bean Validation , you can use three alternative for BigDecimal type:
#DecimalMax --->
Sample:
#DecimalMax("30.00")
BigDecimal discount;
#DecimalMin --->
Sample:
#DecimalMin("5.00")
BigDecimal discount;
#Digits --->
Sample:
#Digits(integer=6, fraction=2)
BigDecimal price;
Note:
You can use #Max only for an integer value.