Marek Kliś Marek Kliś - 3 months ago 10
Scala Question

Mockito matchers, scala value class and NullPointerException

I'm using mockito with scalatest. I have following problem when using matcher with value class.



import org.scalatest.FlatSpec
import org.scalatest.mock.MockitoSugar
import org.mockito.BDDMockito._
import org.mockito.Matchers.any

case class FirstId(val value: String) extends AnyVal
case class SecondId(val value: String) extends AnyVal

trait MockedClass {
def someMethods(firstId: FirstId, secondId: SecondId): Int
}

class ValueClassSpec() extends FlatSpec with MockitoSugar {

val mockedClass = mock[MockedClass]
val secondId = SecondId("secondId")

"Matchers" should "work for value class" in {
// given
given(mockedClass.someMethods(any[FirstId], org.mockito.Matchers.eq(secondId))).willReturn(3)
// when
val result = mockedClass.someMethods(FirstId("firstId"), secondId)
// then
assert(result == 3)
}

}


and the result is:

ValueClassSpec:
Matchers
- should work for value class *** FAILED ***
java.lang.NullPointerException:
at io.scalac.fow.party.ValueClassSpec$$anonfun$1.apply$mcV$sp(ValueClassSpec.scala:22)
at io.scalac.fow.party.ValueClassSpec$$anonfun$1.apply(ValueClassSpec.scala:20)
at io.scalac.fow.party.ValueClassSpec$$anonfun$1.apply(ValueClassSpec.scala:20)
at org.scalatest.Transformer$$anonfun$apply$1.apply(Transformer.scala:22)
at org.scalatest.Transformer$$anonfun$apply$1.apply(Transformer.scala:22)
at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.FlatSpecLike$$anon$1.apply(FlatSpecLike.scala:1639)
...


I found similar question (Scala Value classes and Mockito Matchers don't play together) but without any advice.

Is there any posibility to use mockito matchers with scala value class?

Lib versions: scala 2.11.2, mockito 1.10.8, scalatest 2.1.6

Answer

The proper solution is:

case class StringValue(val text: String) extends AnyVal
case class LongValue(val value: Long) extends AnyVal

val eqFirst: StringValue = StringValue(org.mockito.Matchers.eq("first"))
val anySecond: StringValue = StringValue(org.mockito.Matchers.any[String])

val eqFirst: LongValue = LongValue(org.mockito.Matchers.eq(1L))
val anySecond: LongValue = LongValue(org.mockito.Matchers.any[Long])