Test.scala

package finagleprime.endpoints

import org.http4s._
import org.http4s.dsl._
import cats.implicits._
import cats.effect.Sync
import cats.data.EitherT

final class Test[F[_]: Sync] extends Http4sDsl[F] {
    
  val endpoint: HttpRoutes[F] = HttpRoutes.of[F] {

    case GET -> Root / "test" / test =>
      encodeEither[String](testRun(test))
  }

  def parse(s: String): Either[Throwable, String] =
    if (s.equals("test")) Either.right(s)
    else Either.left(new NumberFormatException(s"${s} is not a valid integer."))

  def testRun(a: String): EitherT[F, Throwable, String] =
     for {
       a <- EitherT(Sync[F].pure(parse(a)))
     } yield a

  def encodeEither[A](either: EitherT[F, Throwable, A])(implicit encoder: EntityEncoder[F, A]): F[Response[F]] = {
    either.foldF(
        err => BadRequest(err.toString()), 
        value => Ok(value)
    )
  }

}