为什么这个specs2测试使用Mockito传递？

假设我有这个接口和类:

abstract class SomeInterface{
  def doSomething : Unit
}

class ClassBeingTested(interface : SomeInterface){
  def doSomethingWithInterface : Unit = {
    Unit
  }
}

请注意,doSomethingWithInterface方法实际上不对接口执行任何操作.

我为它创建了一个测试:

import org.specs2.mutable._
import org.specs2.mock._
import org.mockito.Matchers
import org.specs2.specification.Scope

trait TestEnvironment extends Scope with Mockito{
  val interface = mock[SomeInterface]
  val test = new ClassBeingTested(interface)
}

class ClassBeingTestedSpec extends Specification{
  "The ClassBeingTested" should {
    "#doSomethingWithInterface" in {
      "calls the doSomething method of the given interface" in new TestEnvironment {
        test.doSomethingWithInterface
        there was one(interface).doSomething
      }
    }
  }
}

这个测试通过.为什么？我设置错了吗？

当我摆脱范围:

class ClassBeingTestedSpec extends Specification with Mockito{
  "The ClassBeingTested" should {
    "#doSomethingWithInterface" in {
      "calls the doSomething method of the given interface" in {
        val interface = mock[SomeInterface]
        val test = new ClassBeingTested(interface)
        test.doSomethingWithInterface
        there was one(interface).doSomething
      }
    }
  }
}

测试按预期失败:

[info]   x calls the doSomething method of the given interface
[error]      The mock was not called as expected: 
[error]      Wanted but not invoked:
[error]      someInterface.doSomething();

这两个测试有什么区别？为什么第一个应该失败时通过？这不是Scopes的预期用途吗？