如何做非专用类型有接受函数1的方法?

Question

我有以下类：

class Elem[T](t: T){
def doSome(f: T => Unit):Unit = f(t)
}

所以我想测试给定Elem实例的函数调用(我正在使用 mockito(。运行测试时

val f = mock(classOf[Int => Unit])
new Elem(1).doSome(f)
verify(f).apply(1)

我得到了以下异常：

Wanted but not invoked:
function1.apply$mcVI$sp(1);
However, there was exactly 1 interaction with this mock:
function1.apply(1);

这是合理的，因为Function1专门用于Int。所以使测试作为

val f = mock(classOf[AnyRef => Unit])
new Elem(1.asInstanceOf[AnyRef]).doSome(f)
verify(f).apply(1.asInstanceOf[AnyRef])

工作正常。

有没有办法避免这种丑陋的演员表AnyRef？也许还有比mockito更适合这种情况的工具？

Answer 1

以下是强制编译器使用非专用泛型apply的一种方法：

def verifyGenericApply[X, Y](f: X => Y, x: X): Unit = {
verify(f).apply(x)
}
"Int function" should "invoke non-specialized apply" in {
class Elem[T](t: T){
def doSome(f: T => Unit):Unit = f(t)
}
val f = mock(classOf[Int => Unit])
new Elem(1).doSome(f)
verifyGenericApply(f, 1)
}

我对mockito不够熟悉，无法保证这是惯用语，不过......

Answer 2

ScalaMock 似乎开箱即用：

import org.scalatest._
import org.scalatest.matchers._
import org.scalamock.scalatest.MockFactory
import org.scalamock.scalatest._
class Elem[T](t: T){
def doSome(f: T => Unit):Unit = f(t)
}
class ExampleSpec extends FlatSpec with Matchers with MockFactory {
"Elem.doSome" should "apply given function once" in {
val f = mockFunction[Int, Unit]
f.expects(1).returning({}).once
new Elem(1).doSome(f)
}
}
run(new ExampleSpec)