Playframework Scala Specs2 JSON Matchers

Question

I'm using the Play! framework and trying to work with JSON response messages in Specs2 tests with no success.

What I am trying to do is assert key->value pairs in a JsValue like in the example below ... but I can't get the matchers to correctly pass.

import org.specs2.mutable._
import play.api.libs.json.{Json, JsValue}

class JsonSpec extends Specification {

  "Json Matcher" should {

    "Correctly match Name->Value pairs" in {
      val resultJson:JsValue = Json.parse("""{"name":"Yardies"}""")
      resultJson must  /("name" -> "Yardies")
    }

    "Correctly match Name->Value pairs with numbers as doubles" in {
      val resultJson:JsValue = Json.parse("""{"id":1}""")
      resultJson must  /("id" -> 1.0)
    }
  }
}

Errors I get are

{name : Yardies} doesn't contain '(name,Yardies)'

and

{id : 1.0} doesn't contain '(id,1.0)'

Not very helpful, I imagine that it is something simple I am missing (new to both Scala and Play)

Steve

Answer 1

The JsonMatchers in specs2 should be tightened a little bit. They are Matcher[Any] , where Any is supposed to have a toString method which can be parsed by Scala's json parser (and not Play's one).

The following specification works as expected:

class JsonSpec extends Specification {

  "Json Matcher" should {

    "Correctly match Name->Value pairs" in {
      val resultJson = """{"name":"Yardies"}"""
      resultJson must  /("name" -> "Yardies")
    }

    "Correctly match Name->Value pairs with numbers as doubles" in {
      val resultJson = """{"id":1}"""
      resultJson must  /("id" -> 1.0)
    }
  }
}

In your case I suspect that parsing the toString representation of Play's Json values returns something slightly different what the matchers are expecting. This will be fixed in the next specs2 release.