scala - 测试流式传输响应的 Play 框架 Controller

Question

我有一个发送分 block 响应的 Controller :

def streamDatase2t(query:String): Action[AnyContent] = Action.async {
    req =>
        serivce.getIterator(query).map(res => {
            Ok.chunked(Source.apply(res))
        })
  }

当我尝试检查 Controller 规范中的返回内容时，出现异常:

  "return 200 response with the content of the iterator" in {
      when(serivce.getIterator
      (Matchers.any[Request.DatasetLoad],
        Matchers.any[ResponseFormat], Matchers.any[Int]))
        .thenReturn(Future.successful(new FakeIterable(List("One", "Two", "Three").iterator)))

      val fakeRequest = FakeRequest.apply("GET", s"/data")

      val result = Helpers.route(fakeApp, fakeRequest).get
      checkStatus(result, OK)
      contentAsString(result) // <-- exception here ! 
    }

异常(exception):

NoMaterializer cannot materialize
java.lang.UnsupportedOperationException: NoMaterializer cannot materialize
    at play.api.test.NoMaterializer$.materialize(Helpers.scala:732)
    at akka.stream.scaladsl.RunnableGraph.run(Flow.scala:629)
    at akka.stream.scaladsl.Source.runWith(Source.scala:106)
    at akka.stream.scaladsl.Source.runFold(Source.scala:117)
    at play.api.http.HttpEntity.consumeData(HttpEntity.scala:49)
    at play.api.http.HttpEntity.consumeData$(HttpEntity.scala:48)
    at play.api.http.HttpEntity$Chunked.consumeData(HttpEntity.scala:117)
    at play.api.test.ResultExtractors.contentAsBytes(Helpers.scala:381)
    at play.api.test.ResultExtractors.contentAsBytes$(Helpers.scala:379)
    at play.api.test.Helpers$.contentAsBytes(Helpers.scala:676)

Answer 1

由于异常声明 NoMaterializer 无法实现，您可能需要添加一个 Materializer:

implicit lazy val mat = ActorMaterializer()
implicit lazy val ec = instanceOf[ExecutionContext]