tapirOneOf.scala

//> using scala 3.3.1
//> using dep com.softwaremill.sttp.tapir::tapir-core:1.10.3
//> using dep com.softwaremill.sttp.tapir::tapir-json-circe:1.10.3
//> using dep com.softwaremill.sttp.tapir::tapir-openapi-docs:1.10.3
//> using dep com.softwaremill.sttp.tapir::tapir-jdkhttp-server:1.10.3
//> using dep com.softwaremill.sttp.apispec::openapi-circe-yaml::0.8.0
//> using dep com.softwaremill.sttp.apispec::openapi-circe-yaml::0.8.0

import sttp.tapir.*
import sttp.tapir.json.circe.*
import io.circe.*
import sttp.model.*
import sttp.tapir.docs.openapi.*
import sttp.apispec.openapi.*
import sttp.apispec.openapi.circe.yaml.*
import sttp.tapir.server.jdkhttp.*
import java.net.InetSocketAddress
import scala.util.Random

sealed trait A
case class B(b: String) extends A derives Schema, Encoder.AsObject, Decoder
case class C(c: String) extends A derives Schema, Encoder.AsObject, Decoder
case class D(d: String) extends A derives Schema, Encoder.AsObject, Decoder

@main
def tapirOneOf =
  val myEndpoint = endpoint.get
    .in("path")
    .out(
      oneOf[A](
        oneOfVariant(statusCode(StatusCode.Ok).and(jsonBody[B])),
        oneOfVariant(statusCode(StatusCode.Ok).and(jsonBody[C])),
        oneOfVariant(statusCode(StatusCode.Accepted).and(jsonBody[D]))
      )
    )
    .handle(_ => Right(Random.shuffle(List[A](B(""), C(""), D(""))).head))

  val docs: OpenAPI =
    OpenAPIDocsInterpreter().toOpenAPI(myEndpoint, "My Service", "1.0")

  println(docs.toYaml)

  val server: HttpServer =
    JdkHttpServer().port(8082).addEndpoint(myEndpoint).start()


/*
`curl -v localhost:8080/path` can result both in B and C in case of 200 code, but the schema declares only C

Schema output:
openapi: 3.1.0
info:
  title: My Service
  version: '1.0'
paths:
  /path:
    get:
      operationId: getPath
      responses:
        '200':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/C'
        '202':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/D'
components:
  schemas:
    B:
      title: B
      required:
      - b
      type: object
      properties:
        b:
          type: string
    C:
      title: C
      required:
      - c
      type: object
      properties:
        c:
          type: string
    D:
      title: D
      required:
      - d
      type: object
      properties:
        d:
          type: string
*/