Facing issue testing akka http cache - scala

Question

I am using Akka HTTP cache to cache my result. But i am facing issue to test it.
class GoogleAnalyticsController #Inject()(cache: Cache[String, HttpResponse],
googleAnalyticsApi: GoogleAnalyticsTrait,
googleAnalyticsHelper: GoogleAnalyticsHelper)
(implicit system: ActorSystem, materializer: ActorMaterializer) {
def routes: Route =
post {
pathPrefix("pageviews") {
path("clients" / Segment) { accountsClientId =>
entity(as[GoogleAnalyticsMetricsRequest]) { googleAnalyticsMetricsRequest =>
val googleAnalyticsMetricsKey = "key"
complete(
cache.getOrLoad(googleAnalyticsMetricsKey, _ => getGoogleAnalyticsMetricsData(accountsClientId, googleAnalyticsMetricsRequest))
)
}
}
}
}
private def getGoogleAnalyticsMetricsData(accountsClientId: String,
request: GoogleAnalyticsMetricsRequest) = {
val payload = generate(request)
val response = googleAnalyticsApi.googleAnalyticsMetricResponseHandler(accountsClientId, payload) // response from another microservice
googleAnalyticsHelper.googleAnalyticsMetricResponseHandler(
googleAnalyticsMetricsRequest.metricName, response)
}
}
class GoogleAnalyticsHelper extends LoggingHelper {
def googleAnalyticsMetricResponseHandler(metricName: String, response: Either[Throwable, Long]): Future[HttpResponse] =
response.fold({ error =>
logger.error(s"An exception has occurred while getting $metricName from behavior service and error is ${error.getMessage}")
Marshal(FailureResponse(error.getMessage)).to[HttpResponse].map(httpResponse => httpResponse.copy(status = StatusCodes.InternalServerError))
}, value =>
Marshal(MetricResponse(metricName, value)).to[HttpResponse].map(httpResponse => httpResponse.copy(status = StatusCodes.OK))
)
}
Test case: Sharing only the relevant part
"get success metric response for " + pageviews + " metric of given accounts client id" in { fixture =>
import fixture._
val metricResponse = MetricResponse(pageviews, 1)
val eventualHttpResponse = Marshal(metricResponse).to[HttpResponse].map(httpResponse => httpResponse.copy(status = StatusCodes.OK))
when(cache.getOrLoad(anyString, any[String => Future[HttpResponse]].apply)).thenReturn(eventualHttpResponse)
when(googleAnalyticsApi.getDataFromGoogleAnalytics(accountsClientId, generate(GoogleAnalyticsRequest(startDate, endDate, pageviews))))
.thenReturn(ApiResult[Long](Some("1"), None))
when(googleAnalyticsHelper.googleAnalyticsMetricResponseHandler(pageviews, Right(1))).thenReturn(eventualHttpResponse)
Post(s"/pageviews/clients/$accountsClientId").withEntity(requestEntity) ~>
googleAnalyticsController.routes ~> check {
status shouldEqual StatusCodes.OK
responseAs[String] shouldEqual generate(metricResponse)
}
}
By doing this, I am best to test if the cache has the key but not able to test if cache misses the hit. In code coverage, it misses following highlighted part
cache.getOrLoad(googleAnalyticsMetricsKey, _ =>
getGoogleAnalyticsMetricsData(accountsClientId,
googleAnalyticsMetricsRequest))
If there is a design issue, please feel free to guide me on how can I make my design testable.
Thanks in advance.

Answer 1

I think you don't need to mock the cache. You should create an actual object for cache instead of mocked one.
What you have done is, you have mocked the cache, in this case, the highlighted part will be not called as you are providing the mocked value. In the following stubbing, whenever cache.getOrLoad is found, eventualHttpResponse is returned:
when(cache.getOrLoad(anyString, any[String => Future[HttpResponse]].apply)).thenReturn(eventualHttpResponse)
and hence the function getGoogleAnalyticsMetricsData(accountsClientId, googleAnalyticsMetricsRequest) is never called.