ScalaTest:BeforeAndAfter 未运行

Question

我正在尝试学习如何在 ScalaTest 中使用夹具设置和拆卸。我一直在尝试的一个例子如下:

import org.scalatest._
import scala.collection.mutable

class SampleTest extends FlatSpec with BeforeAndAfter with Matchers{

  before {
     // Setup code
  }

  after {
    // Teardown code
  }

  "A Stack" should "pop values in last-in-first-out order" in {
    val stack = new mutable.Stack[Int]
    stack.push(1)
    stack.push(2)
    stack.pop() should be (2)
    stack.pop() should be (1)
  }

  it should "throw NoSuchElementException if an empty stack is popped" in {
    val emptyStack = new mutable.Stack[Int]
    a [NoSuchElementException] should be thrownBy {
      emptyStack.pop()
    }
  }
}

问题在于根本没有执行之前或之后的 block 。我觉得我完全遵循了项目文档中的说明 - 我做错了什么？

Answer 1

我试过你的例子，它运行良好:

import org.scalatest._
import scala.collection.mutable

class SampleSpec extends FlatSpec with BeforeAndAfter with Matchers{

  before {
    info("Setup code")
  }

  after {
    info("Teardown code")
  }

  "A Stack" should "pop values in last-in-first-out order" in {
    val stack = new mutable.Stack[Int]
    stack.push(1)
    stack.push(2)
    stack.pop() should be (2)
    stack.pop() should be (1)
  }

  it should "throw NoSuchElementException if an empty stack is popped" in {
    val emptyStack = new mutable.Stack[Int]
    a [NoSuchElementException] should be thrownBy {
      emptyStack.pop()
    }
  }
}

将它粘贴到 REPL 中可以得到:

scala> new SampleSpec execute
SampleSpec:
A Stack
+ Setup code 
- should pop values in last-in-first-out order
+ Teardown code 
+ Setup code 
- should throw NoSuchElementException if an empty stack is popped
+ Teardown code 

但是，鉴于您评论说需要说“override def”，我想我知道发生了什么。我认为您的 IDE 可能已将您的代码完成为 BeforeAndAfterEach，即使您想要 BeforeAndAfter。所以你混合了 BeforeAndAfterEach，这确实需要 :override def before...”但是正在查看 BeforeAndAfter 的文档。你能仔细检查一下，看看是否是问题所在？