Mockito doReturn：对重载定义的不明确引用

Question

我正在尝试将Scala系统移植到Mockito2。有一些测试用例doReturn，现在在Mockito中出现2.18.0此错误：

Error:(34, 5) ambiguous reference to overloaded definition,
both method doReturn in object Mockito of type (x$1: Any, x$2: Object*)org.mockito.stubbing.Stubber
and  method doReturn in object Mockito of type (x$1: Any)org.mockito.stubbing.Stubber
match argument types (com.twitter.util.Future[Unit])
doReturn(Future.Unit).when(f.adapterSpy).myFunction(userData, Some(offerId), Always)

进入Mockito.java，doReturn确实像这样超载：

public static Stubber doReturn(Object toBeReturned) 
public static Stubber doReturn(Object toBeReturned, Object... toBeReturnedNext)

这在地球上怎么不总是模棱两可？如何进行编译？

谢谢

Answer 1

Scala backlog 中有一张票。见https://github.com/scala/bug/issues/4775

Answer 2

这也可以通过使用doAnswer代替doReturn

// no good
doReturn(true).when(foo).bar()
// works
doAnswer(_ => true).when(foo).bar()

Answer 3

作为临时的解决方法，您可以执行以下操作：

trait MockitoHelper extends MockitoSugar {
  def doReturn(toBeReturned: Any): Stubber = {
    Mockito.doReturn(toBeReturned, Nil: _*)
  }
}

然后让您的测试混入此MockitoHelper。