ScalaTest AsyncFunSuiteLike multiple asserts

Question

I am rewriting tests that used to test an Akka actor that responded with a String, right now, we use a function that returns a Future[String]. So rewriting the tests using AsyncFunSuiteLike.

Currently I'm looking at a test that has to assert multiple Futures, but I don't seem to understand how to achieve it with AsyncFunSuiteLike.

My test looks as follows:

test("Error responses") {

    NanoHTTPD.Response.Status.values().filter(status => status.getRequestStatus >= 400).map {
      status => {
        val statusCode = status.getRequestStatus
        httpService.setStatusCode(status)
        val responseBody = s"Request failed with status $status"
        httpService.setResponseContent(responseBody)
        val errorMessage = s"Error response (${status.getRequestStatus}): $responseBody"

        myobject.request("123456").map {
          resp => assert(resp === "....")
        }
      }
    }

}

But I am getting an error type missmatch. Expected: Future[Assertion] actual: List[Future[scalatest.Assertion]]

Any idea on how can I achieve multiple assertions within a single test like that?

Answer 1

ScalaTest asynchronous testing expects the test body to return Future[Assertion]. Now your test body returns List[Future[Assertion]]] because

NanoHTTPD.Response.Status.values() ... // Returns List
  ...
    myobject.request("123456").map(resp => assert(resp === "....")} // Returns Future[Assertion]
  ...
}

We can convert List[Future[T]] to Future[List[T]] using

Future.sequence(listOfFutures)

and, we can convert List[Assertion] to Assertion using

assert(listOfAssertions.forall(_ == Succeeded))

Putting this together we get

Future.sequence {
  NanoHTTPD.Response.Status.values().filter(status => status.getRequestStatus >= 400).map {
    status => {
      val statusCode = status.getRequestStatus
      httpService.setStatusCode(status)
      val responseBody = s"Request failed with status $status"
      httpService.setResponseContent(responseBody)
      val errorMessage = s"Error response (${status.getRequestStatus}): $responseBody"

      myobject.request("123456").map {
        resp => assert(resp === "....")
      }
    }
  }
}.map(listOfAssertions => assert(listOfAssertions.forall(_ == Succeeded)))