title: How to test a JSON array from Spray GET response?
body: <p>Spray says that any normal data types, including <code>Seq</code> will get (un)marhsalled to/from JSON, automatically. For some reason, I don't experience this.</p>
  
  <pre><code>import spray.json._
  import DefaultJsonProtocol._
  ...
  
  class RestAPITest
    extends FlatSpec
    with Matchers
    with ScalatestRouteTest
    with MyRoute
  {
    ...
  
    behavior of "MyRoute"
  
    it should "return a list as JSON" in {
      Get("/computers") ~&gt; myRoute ~&gt; check {
        status should equal(OK)
  
        // 'sbt test' gives:
        // "could not find implicit value for evidence parameter of type spray.httpx.unmarshalling.FromResponseUnmarshaller[Seq[String]]"
        //
        responseAs[Seq[String]] should contain theSameElementsAs( List( "A01", "A02", "A03", "E01", "G04" ) )
      }
    }
  </code></pre>
  
  <p>What am I doing wrong?</p>