Multiple routes with difference Accept headers results in swagger.json with incomplete produces

[balthz]

(I'm filing this per discussion with @zarthross on Gitter.)

How to reproduce

import cats.effect.{ExitCode, IO, IOApp, Sync}
import io.circe.generic.auto._
import org.http4s.headers._
import org.http4s.rho.swagger
import org.http4s.server.blaze.BlazeServerBuilder
import org.http4s.syntax.kleisli.http4sKleisliResponseSyntax
import org.http4s.{EntityEncoder, MediaType}
import org.http4s.rho.RhoRoutes

case class SampleResponse(msg: String)

class Routes[F[_]: Sync] extends RhoRoutes[F] {
  def accept(mediaType: MediaType) =
    existsAnd(Accept) { (hdr: Accept) ⇒
      hdr.values.exists(_.mediaRange.satisfiedBy(mediaType))
    }

  {
    implicit val entityEncoder: EntityEncoder[F, SampleResponse] = org.http4s.circe.CirceEntityEncoder.circeEntityEncoder[F, SampleResponse]
    GET / "text-or-json" >>> accept(MediaType.application.json) |>> { () ⇒ Ok(SampleResponse("some JSON")) }
  }
  {
    implicit val encoder: EntityEncoder[F, SampleResponse] = EntityEncoder.stringEncoder[F].contramap(_.toString)
    GET / "text-or-json" >>> accept(MediaType.text.plain)       |>> { () ⇒ Ok(SampleResponse("some text")) }
  }
}

object Bug extends IOApp {
  override def run(args: List[String]): IO[ExitCode] = {
    val httpApp = new Routes[IO]()
      .toRoutes(swagger.syntax.io.createRhoMiddleware())
        .orNotFound

    BlazeServerBuilder[IO]
      .bindHttp(8081, "localhost")
      .withHttpApp(httpApp)
      .resource
      .use(server ⇒ IO.never)
  }
}

Once this is running, I did a

curl -v http://localhost:8081/swagger.json

and got:

  "paths" : {
    "/text-or-json" : {
      "get" : {
        "tags" : [ "text-or-json" ],
        "operationId" : "getText-or-json-Accept",
        "produces" : [ "text/plain" ],
        "parameters" : [ {
          "name" : "Accept",
          "in" : "header",
          "required" : true,
          "type" : "string"
        } ],
        "responses" : {
          "200" : {
            "description" : "OK",
            "schema" : {
              "$ref" : "#/definitions/SampleResponse"
            }
          }
        },
        "deprecated" : false
      }
    }
  }

I'd have expected to see also "application/json" in the "produces" array.

Note

The actual routes work correctly:

$ http -v GET :8081/text-or-json Accept:text/plain
…
SampleResponse(some text)

$  http -v GET :8081/text-or-json Accept:application/json
{
   "msg": "some JSON"
}

[Igosuki]

Having this problem as well, I get consumes : application/*, which is what the swagger js client sends to http4s and so gets rejected with unprocessable entity since it expects application/json...

The culprit is :

  implicit val http4sShowForMediaRange: Show[MediaRange] =
    Show.show(s => s"${s.mainType}/*${MediaRange.extensionsToString(s)}")

[Igosuki]

Plus it's not possible to setup a default consumes that gets appended everywhere, doing so in swagger syntax doesn't work