Play2 Form handling of json with missing property vs null

jsonformtest.scala

import org.specs2.mutable._
import play.api.test._
import play.api.test.Helpers._
import play.api.data._
import play.api.data.Forms._
import play.api.libs.json.Json

class JsonBindingSpec extends Specification {
  
  val missingProperty = Json parse """{}"""
  val nullValue = Json parse """{"foo":null}"""
  val stringValue = Json parse """{"foo":"bar"}"""
 
  "The JSON form processor" should {
    "bind a missing property to None" in {
      form.bind(missingProperty).get must_== None
    }
    "bind a null value to Some(None)" in {
      form.bind(nullValue).get must_== Some(None)
    }
    "bind a 'bar' value to Some(Some(bar))" in {
      println(form.bind(stringValue).get)
      form.bind(stringValue).get must_== Some(Some("bar"))
    }
  }
  
   val form = Form(
      single("foo" -> maybe(optional(text))))
  
  // This needs to be implemented in a way that it returns None on a missing property,
  // but Some[A] when the property exists, even if the value is a null
  def maybe[A](mapping: Mapping[A]): Mapping[Option[A]] = OptionalMapping(mapping)
}