Mockito matchers, scala value class and NullPointerException

问题

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

回答1:

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])

回答2:

I found solution:

val anyFirstId: FirstId = any[String].asInstanceOf[FirstId]
val eqSecondId: SecondId = org.mockito.Matchers.eq[String](secondId.value).asInstanceOf[SecondId]
given(mockedClass.someMethods(anyFirstId, eqSecondId)).willReturn(3)

回答3:

This works for all kinds of extends AnyVal value classes and doesn't need special matchers either:

    given(mockedClass.someMethods(FirstId(anyString), SecondId(org.mockito.Matchers.eq(secondId.value)))).willReturn(3)

回答4:

The newest version of mockito-scala (0.0.9) supports this out of the box, you can do something like

when(myObj.myMethod(anyVal[MyValueClass]) thenReturn "something"

myObj.myMethod(MyValueClass(456)) shouldBe "something"

verify(myObj).myMethod(eqToVal[MyValueClass](456))

Disclaimer: I'm a developer of that library

回答5:

If you have shapeless in your dependencies you could consider my little helper method: https://gist.github.com/Fristi/bbc9d0e04557278f8d19976188a0b733

Instead of writing

UserId(is(context.userId.value))

You can write

isAnyVal(context.userId)

Which is a bit more convenient :-)

来源：https://stackoverflow.com/questions/27289757/mockito-matchers-scala-value-class-and-nullpointerexception

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scala

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scalatest