Bug Report: Hibernate Validator Not Working in Script/Lambda Mode (`BeanValidator.validate(...)`)

[kangmind]

🐛 Bug Report: Hibernate Validator Not Working in Script/Lambda Mode (BeanValidator.validate(...))

Version: Jooby 4.0.4
Mode: Script/Lambda (extends Jooby)
Modules Used:

• jooby-hibernate-validator
• jooby-guice
  Reference:
  https://jooby.io/modules/hibernate-validator/#hibernate-validator-hibernate-integration

---

✅ Expected Behavior

Using the documented method:

post("/v1", BeanValidator.validate(ctx -> {
    UserDto userDto = ctx.body(UserDto.class);
    ...
}));

should automatically validate the UserDto object using
jakarta.validation annotations, e.g., @notblank, and return validation
errors only if fields are invalid.

---

❌ Actual Behavior

Even when all required fields are provided and valid, the validator
returns errors like:

{
  "title": "Validation failed",
  "status": 422,
  "errors": [
    {
      "field": "password",
      "messages": ["password can not empty"],
      "type": "FIELD"
    },
    {
      "field": "username",
      "messages": ["username can not empty"],
      "type": "FIELD"
    }
  ]
}

This does not happen if I manually validate the object.

---

🧪 Reproduction

1. DTO Class

   package app.domain.user;

   import jakarta.validation.constraints.NotBlank;
   import lombok.Data;

   @DaTa
   public class UserDto {
   @notblank(message = "username can not empty")
   private String username;

    @NotBlank(message = "password can not empty")
    private String password;
   

   }

2. ❌ Failing Handler Using BeanValidator.validate(...)

   post("/v1", BeanValidator.validate(ctx -> {
   UserDto userDto = ctx.body(UserDto.class);
   ...
   }));

3. ✅ Working Handler Using Manual Validation

   post("/v2", ctx -> {
   UserDto userDto = ctx.body(UserDto.class);

    Validator validator = require(Validator.class);
    Set<ConstraintViolation<UserDto>> violations = validator.validate(userDto);
    if (!violations.isEmpty()) {
        for (ConstraintViolation<UserDto> v : violations) {
            throw new StatusCodeException(StatusCode.BAD_REQUEST, v.getPropertyPath() + " " + v.getMessage());
        }
    }
   
    ...
   

   });

---

✅ Conclusion

• Validation annotations work correctly with manual validation
• But fail incorrectly using the documented
  BeanValidator.validate(...) approach in script/lambda mode
• This appears to be a bug specific to jooby-hibernate-validator
  integration in non-MVC mode

[kangmind]

Correction: the version is Jooby 4.0.2.