CODEWITHSUNDEEP
scalamockitospecs2
tony_k
tony_k

Reputation: 2061

are there any tricks to working with overloaded methods in specs2?

i've been getting beat up attempting to match on an overloaded method.

i'm new to scala and specs2, so that is likely one factor ;)

so i have a mock of this SchedulerDriver class

and i'm trying to verify the content of the arguments that are being passed to the signature of this launchTasks method:

http://mesos.apache.org/api/latest/java/org/apache/mesos/SchedulerDriver.html#launchTasks(java.util.Collection,%20java.util.Collection)

i have tried the answers style like so:

val mockSchedulerDriver = mock[SchedulerDriver]
mockSchedulerDriver.launchTasks(haveInterface[Collection[OfferID]], haveInterface[Collection[TaskInfo]]) answers { i => System.out.println(s"i=$i") }

and get

ambiguous reference to overloaded definition, both method launchTasks in trait SchedulerDriver of type (x$1: org.apache.mesos.Protos.OfferID, x$2: java.util.Collection[org.apache.mesos.Protos.TaskInfo])org.apache.mesos.Protos.Status and method launchTasks in trait SchedulerDriver of type (x$1: java.util.Collection[org.apache.mesos.Protos.OfferID], x$2: java.util.Collection[org.apache.mesos.Protos.TaskInfo])org.apache.mesos.Protos.Status match argument types (org.specs2.matcher.Matcher[Any],org.specs2.matcher.Matcher[Any])

and i have tried the capture style like so:

val mockSchedulerDriver = mock[SchedulerDriver]
val offerIdCollectionCaptor = capture[Collection[OfferID]]
val taskInfoCollectionCaptor = capture[Collection[TaskInfo]]
there was one(mockSchedulerDriver).launchTasks(offerIdCollectionCaptor, taskInfoCollectionCaptor)

and get:

overloaded method value launchTasks with alternatives: (x$1: org.apache.mesos.Protos.OfferID,x$2: java.util.Collection[org.apache.mesos.Protos.TaskInfo])org.apache.mesos.Protos.Status <and> (x$1: java.util.Collection[org.apache.mesos.Protos.OfferID],x$2: java.util.Collection[org.apache.mesos.Protos.TaskInfo])org.apache.mesos.Protos.Status cannot be applied to (org.specs2.mock.mockito.ArgumentCapture[java.util.Collection[mesosphere.mesos.protos.OfferID]], org.specs2.mock.mockito.ArgumentCapture[java.util.Collection[org.apache.mesos.Protos.TaskInfo]])

any guidance or suggestions on how to approach this appreciated...!

best, tony.

Upvotes: 1

Views: 342

Answers (2)

Eric
Eric

Reputation: 15557

You can use the any matcher in that case:

val mockSchedulerDriver = mock[SchedulerDriver]

mockSchedulerDriver.launchTasks(
 any[Collection[OfferID]],     
 any[Collection[TaskInfo]]) answers { i => System.out.println(s"i=$i")

The difference is that any[T] is a Matcher[T] and the overloading resolution works in that case (whereas haveInterface is a Matcher[AnyRef] so it can't direct the overloading resolution).

Upvotes: 1

Daniel Martin
Daniel Martin

Reputation: 23558

I don't understand why the first alternative didn't work, but the second alternative isn't working because scala doesn't consider implicit functions when resolving which overloaded method to call, and the magic that lets you use a capture as though it were the thing you captured depends on an implicit function call.

So what if you make it explicit?

val mockSchedulerDriver = mock[SchedulerDriver]
val offerIdCollectionCaptor = capture[Collection[OfferID]]
val taskInfoCollectionCaptor = capture[Collection[TaskInfo]]
there was one(mockSchedulerDriver).launchTasks(
    offerIdCollectionCaptor.capture, taskInfoCollectionCaptor.capture)

Upvotes: 0

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