HttpExt.singleRequest with implicit parameters can not be mocked

If I try to mock the object HttpExt (imported like this import akka.http.scaladsl.HttpExt) it will not work with this library. This one will mock the object

import akka.http.scaladsl.HttpExt
import org.scalatest.mockito.MockitoSugar.mock
...

val mockHttp = mock[HttpExt]

this one will not work i.e. it will just return an instance of HttpExt and not a mock

import akka.http.scaladsl.HttpExt
import org.mockito.MockitoSugar.mock

...

val mockHttp = mock[HttpExt]

I also could not spy an HttpExt instance.

I am using

"org.mockito" % "mockito-scala_2.12" % "1.0.1"

and

"org.scalatest" % "scalatest_2.12" % "3.0.5" % "test"

[bbonanno]

@gadcam It actually doesn’t For starters, Scalatest doesn’t provide any mocking library, it only wraps the mock method with a nicer syntax, but you are 100% using the Java Mockito. Java Mockito is completely oblivious to default arguments (and any other Scala-only feature), from the Mockito point of view, they are null if you don’t provide them (you can check this by writing a verify to see what arguments were passed to the method). You can find a more detailed explanation here

[bbonanno]

@gadcam The problem is that mockito-scala is aware of default arguments, if you look at the signature of singleRequest it looks like

  def singleRequest(
    request:           HttpRequest,
    connectionContext: HttpsConnectionContext = defaultClientHttpsContext,
    settings:          ConnectionPoolSettings = defaultConnectionPoolSettings,
    log:               LoggingAdapter         = system.log): Future[HttpResponse]

Now, the log parameter receives as default system.log. As system hasn’t been stubbed, mockito-scala will return a SmartNull (a mock that will fail if you call any method on it) which is the one that is throwing that exception you see…

You have many ways to overcome this, but probably the easiest is to pass a mock of a LoggingAdapter to the singleRequest method so the default value is not used…

BTW, your code would look much cleaner with the new API, e.g.

  val randomRequest = HttpRequest()
  val response      = Future(HttpResponse())
  "mock" should {
    "should work if coming from mockito" in {
      val mockHttp = mock[HttpExt]
      val logger   = mock[LoggingAdapter]

      mockHttp.singleRequest(*, *, *, *) shouldReturn response

      mockHttp.singleRequest(randomRequest, log = logger) should be theSameInstanceAs response
    }
  }