ScalaTest：没有为生成器驱动的属性检查运行任何测试

Question

我正在尝试使用斯卡拉测试和斯卡拉检查设置基于属性的测试...根据预测，似乎我正在成功，但它需要太快了，从我通常的理解来看，ScalaCheck应该告诉你测试是如何运行的，在我的情况下，这些信息是不存在的：

[IJ]sbt:algorithms2_1> testOnly *MedianOf3PartitioningProps
[info] Compiling 1 Scala source to /Users/vasile.gorcinschi/gitPerso/Algorithms/Chapter 2 Sorting/algorithms2_1/target/scala-2.12/test-classes ...
[warn] there was one deprecation warning; re-run with -deprecation for details
[warn] one warning found
[info] Done compiling.

[info] MedianOf3PartitioningProps:
[info] sort
[info] - should sort array of ints from 0 to 100
[info]   +  
[info] ScalaTest
[info] Run completed in 412 milliseconds.
[info] Total number of tests run: 1
[info] Suites: completed 1, aborted 0
[info] Tests: succeeded 1, failed 0, canceled 0, ignored 0, pending 0
[info] All tests passed.
[info] Passed: Total 1, Failed 0, Errors 0, Passed 1

下面是测试类:

class MedianOf3PartitioningProps extends FlatSpec with Matchers with GeneratorDrivenPropertyChecks with Gens {

  private val medianOf3Partitioning = new MedianOf3Partitioning[Int]

  implicit override val generatorDrivenConfig: PropertyCheckConfiguration = PropertyCheckConfig(minSuccessful = 1, maxDiscarded = 500, workers = 1)

  behavior of "sort"

  it should "sort array of ints from 0 to 100" in {
    forAll(arraysGen){  a: Array[Int] =>
      info(s"${a.mkString(",")}")
    medianOf3Partitioning.sort(a) shouldEqual a.sorted }
  }
}

Gens 特征是我的 - 它只包含Gen[数组[Int]的定义：

trait Gens {

  val arraysGen: Gen[Array[Int]] = containerOf[Array, Int](
    chooseNum(Int.MinValue, Int.MaxValue) suchThat { _ < 100 }
  ).suchThat(_.length < 50)
}

我使用这个源进行测试设置。以防万一，我提供了scalacheck和scalatest的版本（来自Dependencies.scala和build.sbt）：

lazy val scalaTest = "org.scalatest" %% "scalatest" % "3.0.5"
...
libraryDependencies ++= {
      val scalaTestVersion = "3.0.5"
      val scalaCheckVersion = "1.14.0"
      Seq(scalaTest % Test,
        "org.scalatest" %% "scalatest" % scalaTestVersion % "test",
        "org.scalacheck" %% "scalacheck" % scalaCheckVersion % "test",
        "com.storm-enroute" %% "scalameter" % "0.9"
      )
    }

Answer 1

基于M. Odersky的“Scala编程”中的小例子，我从< code > GeneratorDrivenPropertyChecks 切换到更一般的< code>PropertyChecks。我还发现了我的< code>Gen[Array[Int]]的问题，所以我也必须检查一下。发布一个有效的解决方案(发现失败的案例),以帮助其他人:

性别特征：

trait Gens {

  val minIntArraysGen: Gen[Array[Int]] = containerOf[Array, Int](Gen.chooseNum(0, 100))
}

基于属性的测试：

import ca.vgorcinschi.Gens
import org.scalatest.MustMatchers._
import org.scalatest.WordSpec
import org.scalatest.prop.PropertyChecks

class MedianOf3PartitioningProps extends WordSpec with PropertyChecks with Gens {

  "sort method" must {
    "sort any Int array" in {
      forAll (minIntArraysGen){ (a: Array[Int]) =>
        whenever(a.nonEmpty) {
          val maybeSorted = new MedianOf3Partitioning[Int].sort(a)
          maybeSorted must equal (a.sorted)
        }
      }
    }
  }
}