Route based marshalling example

RouteTest.scala

package za.co.monadic.kumquat

import spray.testkit.ScalatestRouteTest
import org.scalatest.{FunSpec, Matchers}


import spray.json.DefaultJsonProtocol
import spray.routing.Directives._
import spray.httpx.marshalling.Marshaller
import spray.http.MediaTypes._
import spray.http.HttpEntity

// Data types that we trade in
case class Customer(name: String, no: Int)
case class Part( number: Int, name: String, length: Double)

// Marshallers for application/json (Spray's json)
object JsonMarshallers extends DefaultJsonProtocol {
  implicit val customerM = jsonFormat2(Customer)
  implicit val partM = jsonFormat3(Part)
}

// Custom marshalling for our text/plain
object TextMarshal {
  implicit val customerM = Marshaller.of[Customer](`text/plain`) {
    (value, content, ctx) => ctx.marshalTo(HttpEntity(content, value.toString))
  }
  implicit val partM = Marshaller.of[Part](`text/plain`) {
    (value, content, ctx) => ctx.marshalTo(HttpEntity(content, value.toString))
  }
}

// Map implicit
trait JsonApi {
  import spray.httpx.SprayJsonSupport._
  implicit val cm = sprayJsonMarshallerConverter(JsonMarshallers.customerM)
  implicit val pm = sprayJsonMarshallerConverter(JsonMarshallers.partM)
}

trait TextApi {
  implicit val cm = TextMarshal.customerM
  implicit val pm = TextMarshal.partM
}

// Build marshal format independent routing
sealed trait Routes {
  implicit val cm: Marshaller[Customer]
  implicit val pm: Marshaller[Part]

  val customer = path("customer" / IntNumber ){ id => complete(Customer("Frankie",id)) }
  val part = path("part" / IntNumber ){ partNo => complete(Part(partNo,"Power flubber", 1.33)) }
  val route = pathPrefix("v1_0" ) {
    get {
      part ~ customer
    }
  }
}

// Json mashalled route
object JsonRoutes extends Routes with JsonApi {
  val topRoute = pathPrefix("api" / "json" ) { route }
}

// Text marshalled route
object TextRoutes extends Routes with TextApi {
  val topRoute = pathPrefix("api" / "txt" ) { route }
}

/**
 *  Test case for the configuration above
 */
class RouteTest extends FunSpec with ScalatestRouteTest with Matchers{

  import spray.json._
  import JsonMarshallers._

  describe("Our routes should") {
    it("gets our customers as text") {
      Get("/api/txt/v1_0/customer/233") ~> TextRoutes.topRoute ~> check {
        responseAs[String] should equal(Customer("Frankie", 233).toString)
      }
    }
    it("gets part details as text") {
      Get("/api/txt/v1_0/part/233") ~> TextRoutes.topRoute ~> check {
        responseAs[String] should equal(Part(233, "Power flubber", 1.33).toString)
      }
    }
    it("gets our customers as JSON") {
      Get("/api/json/v1_0/customer/233") ~> JsonRoutes.topRoute ~> check {
        responseAs[String] should equal(Customer("Frankie", 233).toJson.prettyPrint)
      }
    }
    it("gets our part details as JSON") {
      Get("/api/json/v1_0/part/23") ~> JsonRoutes.topRoute ~> check {
        responseAs[String] should equal(Part(23, "Power flubber", 1.33).toJson.prettyPrint)
      }
    }
  }
}