ScalaTest - 如何检查序列的所有项目是否与谓词匹配？

Question

有没有办法显示更好的错误信息？例如下面的代码

it should "check that items satisfy predicate" in {
  List(1,2,3,4,5,6).forall(x => x < 5) should equal (true)
}

只给我以下错误，没有任何描述:

"false did not equal true"

Predicate 不仅可以是least 表达式，还可以是任何其他函数。 至少我找到了https://www.scalatest.org/user_guide/using_matchers#inspectorShorthands .

Answer 1

can not only be least expression, but any other function

使用 inspector尝试

forAll (xs) { x => assert(pred(x)) }

where pred: T => Boolean，它输出索引和谓词失败的信息性错误消息，类似于

- should check that items satisfy predicate *** FAILED ***
  forAll failed, because: 
    at index 4, pred(x) was false (HelloSpec.scala:41) 
  in List(1, 2, 3, 4, 5, 6) (HelloSpec.scala:41)