Question

我的方法ESV.allocate(BLOCK_NUMBER + 1)仅返回Exception中包含的Failure：

Failure(new Exception("Tried to allocate more than available memory"))

但是，我不确定如何测试它。

我尝试使用FunSuite，我把它放在我的单元测试中：

assert(ESV.allocate(BLOCK_NUMBER + 1) == Failure(new Exception("Tried to allocate more than available memory")))

但是，测试失败并显示以下消息：

 Failure(java.lang.Exception: Tried to allocate more than available memory) did not equal Failure(java.lang.Exception: Tried to allocate more than available memory)

这可能是因为我在断言中实例化了一个不同的Exception对象，并且它没有与我正在测试的方法返回的对象相等。

那么如何检查方法返回的结果呢？

Answer 1

比较类而不是比较绝对值。

assert(ESV.allocate(BLOCK_NUMBER + 1).getClass == classOf[Failure[_]])

如果你想检查异常消息，那么

assert((ESV.allocate(BLOCK_NUMBER + 1).getClass == classOf[Failure[_]]) && (ESV.allocate(BLOCK_NUMBER + 1).failed.get.getMessage == Failure(new Exception("Tried to allocate more than available memory")).failed.get.getMessage))

或

assert((ESV.allocate(BLOCK_NUMBER + 1).getClass == classOf[Failure[_]]) && ESV.allocate(BLOCK_NUMBER + 1).failed.get.getMessage == new Exception("Tried to allocate more than available memory").getMessage)

更好的解决方案

implicit class TryUtils[A](something: Try[A]) {
  def compare[B](other: Try[B]): Boolean = {
    (something, other) match {
      case (Success(a), Success(b)) => a == b
      case (Failure(a), Failure(b)) => a.getClass == b.getClass && (a.getMessage == b.getMessage)
      case (_, _) => false
    }
  }
}

用法：

assert(ESV.allocate(BLOCK_NUMBER + 1) compare Failure(new Exception("Tried to allocate more than available memory")))

断言抛出了正确的异常

1 个答案: