您如何在用 scala 编写的 JUnit 4 测试中实现 @BeforeClass 语义？

Question

我继承了一些用 scala 编写的 JUnit 测试，这些测试需要修复才能使用 @BeforeClass 语义。我知道 @BeforeClass 注释只能应用于静态方法。我知道在“伴侣”对象（而不是 scala 类）中定义的方法是静态的。如何在测试类中的各个实例方法之前调用一次测试方法？

Answer 1

object TestClass {

  @BeforeClass
  def stuff() {
    // beforeclass stuff
  }

}

class TestClass {

  @Test
  ...

}

似乎有效...

Answer 2

我不得不转移到 specs2 以使用 Scala 实现此功能。只是添加一个例子来帮助那些与原始海报有同样问题但还不知道 specs2 的人。

specs2 方式使用“步骤”的概念来完成测试套件的设置和拆卸。如果您使用 JUnitRunner 运行，所有使用 JUnit 的 Ant 脚本和 IDE 仍将知道如何运行它。下面是一个使用来自 specs2 的可变规范的示例：

import org.specs2.mutable.Specification
import org.junit.runner.RunWith
import org.specs2.runner.JUnitRunner

@RunWith(classOf[JUnitRunner])
class MutableSpecs2ExampleTest extends Specification {

  var firstStep: String = null
  var secondStep: String = null
  var thirdStep: String = null
  //Steps are guaranteed to run serially
  step{println("Loading Spring application context...");firstStep="Hello World"}
  step{println("Setting up mocks...");secondStep = "Hello Scala"}

  //The fragments should be run in parallel by specs2
  "Some component Foo in my project" should{
    " pass these tests" in {
      println("Excersizing some code in Foo")
      firstStep must startWith("Hello") and endWith("World")
    }
    " pass theses other tests" in  {
      println("Excersizing some other code in Foo")
      firstStep must have size(11)
    }
  }
  "Some component Bar in my project" should{
    " give the correct answer" in {
      println("Bar is thinking...")
      secondStep must startWith("Hello") and endWith("Scala")
      thirdStep must be equalTo null
    }
  }
  step{println("Tearing down resources after tests...");thirdStep = "Hello Specs2"}
}

这是一个不可变规范的示例：

import org.specs2.Specification
import org.specs2.specification.Step
import org.junit.runner.RunWith
import org.specs2.runner.JUnitRunner

@RunWith(classOf[JUnitRunner])
class Specs2ExampleTest extends Specification{
  var firstStep: String = null
  var secondStep: String = null
  var thirdStep: String = null

  def is =
  "This is a test with some set-up and tear-down examples" ^
                                                           p^
    "Initialize"                                           ^
                                                           Step(initializeDependencies())^
                                                           Step(createTestData())^
    "Component Foo should"                                 ^
      "perform some calculation X "                        !testX^
      "perform some calculation Y"                         !testY^
                                                           p^
    "Tidy up"                                              ^
                                                           Step(removeTestData())^
                                                           end
    def testX = {
      println("testing Foo.X")
      firstStep must be equalTo("Hello World")
    }
    def testY = {
      println("testing Foo.Y")
      secondStep must be equalTo("Hello Scala")
      thirdStep must be equalTo null
    }

  def initializeDependencies(){
    println("Initializing Spring applicaiton context...")
    firstStep = "Hello World"
  }
  def createTestData(){
    println("Inserting test data into the db...")
    secondStep = "Hello Scala"
  }

  def removeTestData(){
    println("Removing test data from the db...")
    println("Tearing down resources...")
    thirdStep = "Hello Specs2"
  }
}

Answer 3

您没有具体说明您是指 OO 编程意义上的继承还是“从其他人那里接管”这个词的含义。

在后一种情况下，我建议您使用 ScalaTest 或 Specs2 重写该东西并将其公开为 JUnit 测试（两个框架都支持这一点），以便它与您的任何其他工具和流程集成已经到位了。