writing a rule using multiple fields

Given the following data structure

  case class Family(name: String, children: Set[Child], mainPet: Pet, otherPets: Seq[Pet])
  object Family {
    implicit val validations: Validator[Family] = Validator
      .derived[Family]
      .rule[String](_.name, _.nonEmpty, "is required")
  }

Is there a way to write a rule that combines more than one field? E.g.

• mainPet can’t be the same as one of the otherPets
• mainPet name can’t be the same as one of the childrens’ name

I tried writing a selector that would map a tuple, e.g. Family => (String, Pet), but it looks like the macro won’t support that.

val familyNameCantBeSameAsMainPet = (pair: (String, Pet)) => pair._1 != pair._2.name
val nameAndMainPetSelector = (family: Family) => (family.name, family.mainPet)
...
...
.rule[(String, Pet)](nameAndMainPetSelector, familyNameCantBeSameAsMainPet, "testing tuple selector")

[andyczerwonka]

We can throw this one on the roadmap as a feature request for custom naming. Closing.

[krzemin]

Well, empty path here means root path. So in this context I believe it’s correct as for such validation the problem is due to invalid relationship between different field values.

When you have Family nested (or in a collection), you get your family-level errors prefixed with non empty path.

If you really need to, you can assign this error to a single specific field (name? using 3 arg rule). Other options are not supported currently.