Macro Testing (macro)

Macro.scala

package ajr.scala3test

import scala.quoted.*
import upickle.default.Writer


def callImpl(obj: Expr[MyObject], argsExpr: Expr[Seq[Any]])(using Quotes): Expr[String] =
   import quotes.reflect.report
   argsExpr match
      case Varargs(argExprs) =>
         val argShowedExprs = argExprs.map {
            case '{ $arg: tp } =>
              val str = Type.show[tp]
              println(s"matched arg=$arg str=$str")

              Expr.summon[Writer[tp]] match
                case Some(showExpr) =>                  
                  '{ upickle.default.write($arg)($showExpr) }
                case None =>
                  report.error(s"could not find implicit for ${Type.show[Writer[tp]]}", arg); '{???}
         }
         val newArgsExpr = Varargs(argShowedExprs)
         '{ "[" + $newArgsExpr.mkString(",") + "]" }
         
      case _ =>
        report.error(s"Args must be explicit", argsExpr)
        '{???}