将Scalacheck与Inside trait结合使用

Question

我有一个非常简单的场景:测试任何一对长度为10的随机字符串作为参数传递给一个case类对(一个正在测试的自定义字符串)应该是相同的。

class ExercisesPropSpec extends PropSpec with Checkers with Matchers with Inside{

  import Exercises._

  lazy val genPairs = for {
    left <- Gen.listOfN(10, Gen.alphaChar)
    right <- Gen.listOfN(10, Gen.alphaChar)
  } yield (left.mkString, right.mkString)

  property("pattern match tuples of alphanumerics to our custom pair class"){
    forAll(genPairs) {case (left: String, right: String) =>
      val pair = Pair(left, right)
      inside(pair) { case Pair(firstName, lastName) =>
        firstName shouldEqual(left)
        lastName shouldEqual(right)
      }
    }
  }
}

但是，当我从sbt运行测试时，我只得到这个编译错误：

Compiling 1 Scala source to /home/vgorcinschi/ideaProjects/Learning Concurrent Programming in Scala/chapter01_introduction/target/scala-2.12/test-classes ...
[error] ~/ideaProjects/Learning Concurrent Programming in Scala/chapter01_introduction/src/test/scala/org/learningconcurrency/ExercisesPropSpec.scala:18:28: No implicit view available from org.scalatest.Assertion => org.scalacheck.Prop.
[error]     check(forAll(genPairs) {case (left: String, right: String) =>
[error]                            ^

斯卡拉切克烹饪书中的一个注解说

该错误消息表明，我们的属性检查没有按照布尔逻辑进行评估

我希望内部块最终应该返回布尔值。如果您能指出我在这个实现中理解基于属性的测试或使用Inside trait时缺少什么，我将不胜感激。

Answer 1

你只需要写

firstName == left && lastName == right

相反

(如果< code>shouldEqual确实返回了< code>Boolean，则< code > first name should equal(left)的结果将被丢弃。)