[Scala] Transforms one case class into another as long as the fields are a subset of the other via LabelledGeneric; Scastie link https://scastie.scala-lang.org/lloydmeta/ra0dvrV5Q2uxruQKoR020Q/2

Transform.scala

@ import $ivy.{`com.chuusai::shapeless:2.3.3`}

import shapeless._, ops.hlist.Align, ops.hlist.SelectAll, SelectAll._

class Transform[T] {

  // The fun stuff. Given an S, returns a T, if S has the right (subset of) fields
  def apply[S, SR <: HList, TR <: HList](s: S)(
      implicit
      genS: LabelledGeneric.Aux[S, SR],
      genT: LabelledGeneric.Aux[T, TR],
      selectAll: SelectAll[SR, TR],
      align: Align[SelectAll[SR, TR]#Out, TR]): T =
    genT.from(align(selectAll(genS.to(s))))
}

object Transform {

  // Convenience method for building an instance of `Transform`
  def into[T] = new Transform[T]
}