type classes

tc.scala

private object Validations {
  trait NotEmpty[F[_], T] {
    def validate(field: F[T]): Boolean
  }

  implicit def optionNotEmpty[T]: NotEmpty[Option, T] = field => field.isDefined
  implicit def listNotEmpty[T]: NotEmpty[List, T] = field => field.nonEmpty

  def notEmpty[F[_], T](field: F[T])(implicit ev: NotEmpty[F, T]): Boolean = ev.validate(field)
}

import Validations._

case class Template(url: Option[String],
                    expectedHttpStatus: List[Int]) {
  require(notEmpty(url), "url cannot be empty")
  require(notEmpty(expectedHttpStatus), "expectedHttpStatus cannot be empty")
}