scala - 为什么这个 specs2 测试使用 Mockito 通过？

Question

假设我有这个接口(interface)和类:

abstract class SomeInterface{
  def doSomething : Unit
}

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

请注意，doSomethingWithInterface 方法实际上并没有对接口(interface)做任何事情。

我为它创建了一个测试，如下所示:

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
      }
    }
  }
}

该测试通过。为什么？我设置错了吗？

当我摆脱范围时:

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了？这不是 Scopes 的预期用途吗？

Answer 1

当你混入 Mockito特质到另一个特质，你可以创造像 there was one(interface).doSomething 这样的期望.如果这样的表达式失败，它只会返回 Result ，它不会抛出 Exception .然后它会在 Scope 中丢失。因为它只是特征体内的“纯”值。

但是，如果您混入 Mockito mutable.Specification 的特征然后在失败时会抛出异常。这是因为 mutable.Specification类指定应该有 ThrownExpectations通过混合这种特性。

因此，如果您想创建一个扩展两个 Scope 的特征您可以:

从规范内部创建特征，而不是让它扩展 Mockito:

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

像你一样创建特征和规范，但要混入 org.specs2.execute.ThrownExpectations

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

class MySpec extends mutable.Specification with Mockito {
  ...
}