`fieldWithArgs` breaks list optionality of fields

[Paul Daniels]

Consider:

import caliban._
import caliban.schema._


case class MyArgs(int: Int)
case class Query(
  values: MyArgs => List[String],
  values1: MyArgs => String
)

implicit val myArgsSchema: Schema[Any, MyArgs] = Schema.gen
implicit val myArgsBuilder: ArgBuilder[MyArgs] = ArgBuilder.gen

implicit val schema: Schema[Any, Query] = Schema.obj("Query")(
  implicit fa => List(
    Schema.fieldWithArgs("values")(_.values),
    Schema.fieldWithArgs("values1")(_.values1)
  )
)

val api = graphQL(RootResolver(Query(_ => Nil, _ => "")))

api.render

This prints:

schema {
  query: Query
}

type Query {
  values(int: Int!): [String!]
  values1(int: Int!): String
}

Which makes the return value optional instead of non-null as it should be (note that this doesn't happen with Schema.gen or auto derivation, no does it happen with a normal arg-less field.

Reproduction: https://scastie.scala-lang.org/Dv987mCCRtqQbBDLRysUlg

[Pierre Ricadat]

It should be changed to () => if (ev1.optional) t else t.nonNull with t = ev1.toType_(fa.isInput, fa.isSubscription).