Automatic typeclass (scalacheck arbitrary here) generation using Shapeless

shapeless-quickcheck.scala

scala> :paste
// Entering paste mode (ctrl-D to finish)

import org.scalacheck.Prop.forAll
import org.scalacheck.Properties
import shapeless.contrib.scalacheck._

case class WebServerConfig(hostname: String, port: Int)
case class ApplicationConfig(webServer: WebServerConfig)

class Application(applicationConfig: ApplicationConfig) {
  import applicationConfig._
  def callWebServer(s: String): String = s"This web server on ${webServer.hostname}:${webServer.port} was called with $s"
}

// Exiting paste mode, now interpreting.

import org.scalacheck.Prop.forAll
import org.scalacheck.Properties
import shapeless.contrib.scalacheck._
defined class WebServerConfig
defined class ApplicationConfig
defined class Application

scala> val prop = forAll { (c: ApplicationConfig, s: String) =>
     |     val app = new Application(c)
     |     val response = app.callWebServer(s)
     |
     |     response.contains(c.webServer.hostname) && response.contains(s)
     |   }
prop: org.scalacheck.Prop = Prop

scala> prop.check
+ OK, passed 100 tests.