Mockito's Answer in ScalaTest

问题

Is there some alternative to Mockito's Answer in ScalaTest? I was going through its documentation, but didn't find anything.

I would like to, for example, execute some logic on arguments of a stubbed method. In Mockito, I would do something like this:

when(mock.create(any(A.class))).thenAnswer(new Answer() {
    Object answer(InvocationOnMock invocation) {
        A firstArg = (A) invocation.getArguments()[0];
        firstArg.callMethod();
        return null;
    }
});

In ScalaTest, I'm fine with using Mockito, as well. However, it would be nice if there was some more Scala-friendly syntax of defining such Answer.

Thank you.

回答1:

I just found this blog post. It describes how to use implicit conversions to achieve what you want. If you define an implicit conversion like this

implicit def toAnswerWithArgs[T](f: InvocationOnMock => T) = new Answer[T] {
    override def answer(i: InvocationOnMock): T = f(i)
}

you can call thenAnswer with a simple function as argument:

when(mock.someMethodCall()).thenAnswer((i) => calculateReturnValue())

There is also a slightly shorter alternative version for the case when your mocked method has no arguments. Follow the link for details.

回答2:

Define this helper function:

def answer[T](f: InvocationOnMock => T): Answer[T] = {
  new Answer[T] {
    override def answer(invocation: InvocationOnMock): T = f(invocation)
  }
}

And use it like this, e.g. for returning a Future[MyClass] containing any argument passed to a method:

when(myRepository.create(any[MyClass]())).thenAnswer(answer({ invocation =>
  Future.successful(invocation.getArguments.head.asInstanceOf[MyClass])
}))

回答3:

If you mix in the trait MockitoSugar, you can create a mock and and pass it an answer using this syntax:

mock[Collaborator](new Answer(){ ... })

回答4:

Have you tried ScalaMock? It is also integrated with ScalaTest and provides a more Scala-friendly API.

来源：https://stackoverflow.com/questions/15024352/mockitos-answer-in-scalatest

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scala

mockito

scalatest