[BUG] incorrect names for newtyped map schemas about tapir

[kciesielski]

@lgmyrek thanks for reporting. This one is tricky to tackle. The @newtype macro generates code like

package object Defs {
  type UserId = UserId.Type
  object UserId {
    type Repr = String
    type Base = Any { type UserId$newtype }
    trait Tag extends Any
    type Type <: Base with Tag

    def apply(x: String): UserId = x.asInstanceOf[UserId]

    implicit final class Ops$newtype(val $this$: Type) extends AnyVal {
      def value: String = $this$.asInstanceOf[String]
    }
  }
}

I simplified the inner type to String but it doesn't change the fact, that the resolved type name will be UserId.Type, which in the end results in Map_Type_Type. I tried to find a way to work around this, but so far without success. Maybe it's the newtype library that could change the Type type to something like UserIdType 🤔

[lgmyrek]

You could try to always name the schemas for new types eg:

  implicit def namedSchemaForNewType[A, B: WeakTypeTag](
    implicit
    ev: Coercible[Schema[A], Schema[B]],
    schema: Schema[A],
  ): Schema[B] = {
    val s = symbolOf[B]

    ev(schema).name(SName(s.fullName))
  }
  

tho this surely needs some work to also handle newtypes with generic params and I do not know the implications of always naming those for compatibility and other schema interactions