当 scalatest 检测到故障时如何忽略测试实用程序方法？

Question

我在测试中有这个方便的方法：

  def assertFormat[T: SexpFormat](start: T, expect: Sexp): Unit = {
    val sexp = start.toSexp
    assert(sexp === expect, s"${sexp.compactPrint} was not ${expect.compactPrint}")
    expect.convertTo[T] should be(start)
  }

这基本上是运行我经常使用的断言模式的便利。

不可能将其重写为 Matcher，因为对 SexpFormat[T] 的隐含要求（尽管我很想听听不需要我这样做的方法在foo should roundTrip[MyFormat](...))

中写入类型MyFormat

如果此实用程序方法中的任何测试失败，scalatest 会将 assertFormat 的内部标记为测试失败的原因。但是我真的想让scalatest检测到这个方法的caller是测试的原因。我该怎么做？

即当前输出为

[info] - should support custom missing value rules *** FAILED ***
[info]   SexpNil did not equal SexpCons(SexpSymbol(:duck),SexpCons(SexpNil,SexpNil)) nil was not (:duck nil) (FormatSpec.scala:11)
[info]   org.scalatest.exceptions.TestFailedException:
[info]   at org.scalatest.Assertions$class.newAssertionFailedException(Assertions.scala:529)
[info]   at org.scalatest.FlatSpec.newAssertionFailedException(FlatSpec.scala:1691)
[info]   at org.scalatest.Assertions$AssertionsHelper.macroAssert(Assertions.scala:502)
[info]   at org.ensime.sexp.formats.FormatSpec$class.assertFormat(FormatSpec.scala:11)
[info]   at org.ensime.sexp.formats.test.FamilyFormatsSpec.assertFormat(FamilyFormatsSpec.scala:151)
[info]   at org.ensime.sexp.formats.test.FamilyFormatsSpec.roundtrip(FamilyFormatsSpec.scala:156)
[info]   at org.ensime.sexp.formats.test.FamilyFormatsSpec$$anonfun.apply(FamilyFormatsSpec.scala:222)
[info]   at org.ensime.sexp.formats.test.FamilyFormatsSpec$$anonfun.apply(FamilyFormatsSpec.scala:221)

FormatSpec.scala:11 是定义我的 assertFormat 的地方。真正的失败是在 FamilyFormatsSpec.scala:222（调用 另一个 便捷方法 FamilyFormatsSpec.scala:156）

Answer 1

这在 ScalaTest 3.0 中是可能的，方法是在您的自定义断言中采用隐式 org.scalactic.source.Position。每当您的 assertFormat 方法被调用时，该位置就会被计算（通过宏），并且该位置将由 assertFormat 内的断言和匹配器表达式选取。这是它的样子：

import org.scalactic.source

def assertFormat[T: SexpFormat](start: T, expect: Sexp)(implicit pos: source.Position): Unit = {
  val sexp = start.toSexp
  assert(sexp === expect, s"${sexp.compactPrint} was not ${expect.compactPrint}")
  expect.convertTo[T] should be(start)
}

下面的例子说明了这一点。如果您在 class 路径上有 ScalaTest 3.0，只需：将以下文件加载到 Scala REPL 中：

:paste

import org.scalatest._
import org.scalactic._
import Matchers._

case class Sexp(o: Any) {
  def compactPrint: String = o.toString
  def convertTo[T: SexpFormat]: Sexp = implicitly[SexpFormat[T]].convertIt(o)
  override def toString = "I'm too sexp for my shirt."
}

trait SexpFormat[T] {
  def convertIt(o: Any): Sexp = new Sexp(o)
}

implicit class Sexpify(o: Any) {
  def toSexp: Sexp = new Sexp(o)
}

implicit def universalSexpFormat[T]: SexpFormat[T] = new SexpFormat[T] {}

def assertFormat[T: SexpFormat](start: T, expect: Sexp): Unit = {
  val sexp = start.toSexp
  assert(sexp === expect, s"${sexp.compactPrint} was not ${expect.compactPrint}")
  expect.convertTo[T] should be(start)
}

import org.scalatest.exceptions.TestFailedException

val before = intercept[TestFailedException] { assertFormat(1, new Sexp) }

println(s"${before.failedCodeStackDepth} - This stack depth points to the assert call inside assertFormat")

import org.scalactic.source

def betterAssertFormat[T: SexpFormat](start: T, expect: Sexp)(implicit pos: source.Position): Unit = {
  val sexp = start.toSexp
  assert(sexp === expect, s"${sexp.compactPrint} was not ${expect.compactPrint}")
  expect.convertTo[T] should be(start)
}

val after = intercept[TestFailedException] { betterAssertFormat(1, new Sexp) }

println(s"${after.failedCodeStackDepth} - This stack depth is the betterAssertFormat call itself in your test code")

它将打印：

3 - This stack depth points to the assert call inside assertFormat
4 - This stack depth is the betterAssertFormat call itself in your test code

当 scalatest 检测到故障时如何忽略测试实用程序方法？

how to ignore test utility methods when scalatest detects failures?

scala

scalatest