问题描述
使用ScalaTest时，我遇到了很难调试的错误。奇怪的是，这似乎在我的程序没有Main对象时发生，但是在它确实具有Main对象时却没有发生。我的代码实际上只是使用带有多态方法的类型类来从列表中获取切片，并且看起来像这样（为这个冗长的示例表示歉意，我已尽力减少了它的数量）：
package sportarray
object ArrayDefs {
abstract class IsArr[A,I0,DT] {
def getElem(self: A,i: Int): DT
def getSlice[R](self: A,r: R)(implicit sliceTc: IsSlice[R]): sliceTc.Out = sliceTc.getSlice(self,r)
trait IsSlice[R] {
type Out
def getSlice(self: A,ref: R): Out
}
object IsSlice {
implicit val iLocTCForInt = new IsSlice[Int] {
type Out = DT
def getSlice(self: A,ref: Int): Out = getElem(self,ref)
}
implicit val iLocTCForList = new IsSlice[List[Int]] {
type Out = List[DT]
def getSlice(self: A,ref: List[Int]): Out = ref.map(getElem(self,_))
}
}
}
object IsArrSyntax {
implicit class IsArrOps[A,T](self: A)(implicit
tc1d: IsArr[A,T]
) {
def getElem(i: Int) = tc1d.getElem(self,i)
def getSlice[R](r: R)(implicit sliceTc: tc1d.IsSlice[R]) = tc1d.getSlice(self,r)
}
}
}
object listofListsObj {
import ArrayDefs._
case class List1d[I0,T] (
indices: List[I0],data: List[T],)
implicit def list1dis1dSpArr[A,T] =
new IsArr[List1d[I0,T],T] {
def getElem(self: List1d[I0,i: Int) = self.data(i)
}
}
我的测试很简单，看起来像这样，位于测试目录中自己的文件中：
package sportarray
import org.scalatest.flatspec.AnyFlatSpec
import org.scalatest.matchers.should.Matchers
class ArraySpec extends AnyFlatSpec with Matchers {
"List" should "act as an array" in {
import ArrayDefs._
import ArrayDefs.IsArrSyntax._
import listofListsObj._
val list1d = List1d[Int,Double](List(1,2,3),List(1.0,2.0,3.0))
assert(list1d.getSlice(1) == 2.0)
}
}
如果我按原样sbt test会出现以下错误：
java.lang.NoSuchFieldError: sportarray$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
at sportarray.ArraySpec.$anonfun$new$1(HelloSpec.scala:12)
at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
然后我尝试将Main类添加到程序中，以查看这是测试问题还是代码本身问题：
object Main extends App {
import ArrayDefs._
import ArrayDefs.IsArrSyntax._
import listofListsObj._
val list1d = List1d[Int,3.0))
assert(list1d.getSlice(1) == 2.0)
}
如果我sbt run可以很好地工作，而且奇怪的是，它还允许我运行sbt test而没有任何问题。如果然后删除该主类，则sbt test再次失败。有人能对这里发生的事情有所了解吗？
感谢您的帮助！
解决方法
实际上我从命令行ran进行了Scalatest，它成功了
$ scalac -cp .:scalactic_2.13-3.2.2.jar:scalatest_2.13-3.2.2.jar:scalatest-core_2.13-3.2.2.jar:scalatest-flatspec_2.13-3.2.2.jar:scalatest-matchers-core_2.13-3.2.2.jar:scalatest-shouldmatchers_2.13-3.2.2.jar:scalatest-compatible-3.2.2.jar App.scala AppTest.scala
$ scala -cp .:scalactic_2.13-3.2.2.jar:scalatest_2.13-3.2.2.jar:scalatest-core_2.13-3.2.2.jar:scalatest-flatspec_2.13-3.2.2.jar:scalatest-matchers-core_2.13-3.2.2.jar:scalatest-shouldmatchers_2.13-3.2.2.jar:scalatest-compatible-3.2.2.jar:scala-xml_2.13-1.3.0.jar org.scalatest.run AppTest
Run starting. Expected test count is: 1
AppTest:
List
- should act as an array
Run completed in 151 milliseconds.
Total number of tests run: 1
Suites: completed 1,aborted 0
Tests: succeeded 1,failed 0,canceled 0,ignored 0,pending 0
All tests passed.
在IntelliJ和sbt中失败了：
（IntelliJ）
An exception or error caused a run to abort: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
at AppTest.$anonfun$new$1(AppTest.scala:10)
at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
at org.scalatest.TestSuite.withFixture(TestSuite.scala:196)
at org.scalatest.TestSuite.withFixture$(TestSuite.scala:195)
at org.scalatest.flatspec.AnyFlatSpec.withFixture(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.invokeWithFixture$1(AnyFlatSpecLike.scala:1681)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTest$1(AnyFlatSpecLike.scala:1693)
at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
at org.scalatest.flatspec.AnyFlatSpecLike.runTest(AnyFlatSpecLike.scala:1693)
at org.scalatest.flatspec.AnyFlatSpecLike.runTest$(AnyFlatSpecLike.scala:1675)
at org.scalatest.flatspec.AnyFlatSpec.runTest(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTests$1(AnyFlatSpecLike.scala:1751)
at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:413)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:390)
at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:427)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:396)
at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:475)
at org.scalatest.flatspec.AnyFlatSpecLike.runTests(AnyFlatSpecLike.scala:1751)
at org.scalatest.flatspec.AnyFlatSpecLike.runTests$(AnyFlatSpecLike.scala:1750)
at org.scalatest.flatspec.AnyFlatSpec.runTests(AnyFlatSpec.scala:1685)
at org.scalatest.Suite.run(Suite.scala:1112)
at org.scalatest.Suite.run$(Suite.scala:1094)
at org.scalatest.flatspec.AnyFlatSpec.org$scalatest$flatspec$AnyFlatSpecLike$$super$run(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$run$1(AnyFlatSpecLike.scala:1796)
at org.scalatest.SuperEngine.runImpl(Engine.scala:535)
at org.scalatest.flatspec.AnyFlatSpecLike.run(AnyFlatSpecLike.scala:1796)
at org.scalatest.flatspec.AnyFlatSpecLike.run$(AnyFlatSpecLike.scala:1794)
at org.scalatest.flatspec.AnyFlatSpec.run(AnyFlatSpec.scala:1685)
at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:45)
at org.scalatest.tools.Runner$.$anonfun$doRunRunRunDaDoRunRun$13(Runner.scala:1320)
at org.scalatest.tools.Runner$.$anonfun$doRunRunRunDaDoRunRun$13$adapted(Runner.scala:1314)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1314)
at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24(Runner.scala:993)
at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24$adapted(Runner.scala:971)
at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1480)
at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:971)
at org.scalatest.tools.Runner$.run(Runner.scala:798)
at org.scalatest.tools.Runner.run(Runner.scala)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.runScalaTest2or3(ScalaTestRunner.java:40)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.main(ScalaTestRunner.java:27)
（sbt）
[error] java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
[error] at AppTest.$anonfun$new$1(AppTest.scala:10)
[error] at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
[error] at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
[error] at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
[error] at org.scalatest.Transformer.apply(Transformer.scala:22)
[error] at org.scalatest.Transformer.apply(Transformer.scala:20)
[error] at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
[error] at org.scalatest.TestSuite.withFixture(TestSuite.scala:196)
[error] at org.scalatest.TestSuite.withFixture$(TestSuite.scala:195)
[error] at org.scalatest.flatspec.AnyFlatSpec.withFixture(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.invokeWithFixture$1(AnyFlatSpecLike.scala:1681)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTest$1(AnyFlatSpecLike.scala:1693)
[error] at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTest(AnyFlatSpecLike.scala:1693)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTest$(AnyFlatSpecLike.scala:1675)
[error] at org.scalatest.flatspec.AnyFlatSpec.runTest(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTests$1(AnyFlatSpecLike.scala:1751)
[error] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:413)
[error] at scala.collection.immutable.List.foreach(List.scala:333)
[error] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[error] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:390)
[error] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:427)
[error] at scala.collection.immutable.List.foreach(List.scala:333)
[error] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[error] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:396)
[error] at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:475)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTests(AnyFlatSpecLike.scala:1751)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTests$(AnyFlatSpecLike.scala:1750)
[error] at org.scalatest.flatspec.AnyFlatSpec.runTests(AnyFlatSpec.scala:1685)
[error] at org.scalatest.Suite.run(Suite.scala:1112)
[error] at org.scalatest.Suite.run$(Suite.scala:1094)
[error] at org.scalatest.flatspec.AnyFlatSpec.org$scalatest$flatspec$AnyFlatSpecLike$$super$run(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$run$1(AnyFlatSpecLike.scala:1796)
[error] at org.scalatest.SuperEngine.runImpl(Engine.scala:535)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.run(AnyFlatSpecLike.scala:1796)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.run$(AnyFlatSpecLike.scala:1794)
[error] at org.scalatest.flatspec.AnyFlatSpec.run(AnyFlatSpec.scala:1685)
[error] at org.scalatest.tools.Framework.org$scalatest$tools$Framework$$runSuite(Framework.scala:318)
[error] at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:513)
[error] at sbt.TestRunner.runTest$1(TestFramework.scala:139)
[error] at sbt.TestRunner.run(TestFramework.scala:154)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.$anonfun$apply$1(TestFramework.scala:317)
[error] at sbt.TestFramework$.sbt$TestFramework$$withContextLoader(TestFramework.scala:277)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:317)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:317)
[error] at sbt.TestFunction.apply(TestFramework.scala:329)
[error] at sbt.Tests$.$anonfun$toTask$1(Tests.scala:311)
[error] at sbt.std.Transform$$anon$3.$anonfun$apply$2(Transform.scala:46)
[error] at sbt.std.Transform$$anon$4.work(Transform.scala:67)
[error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281)
[error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19)
[error] at sbt.Execute.work(Execute.scala:290)
[error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281)
[error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] at java.lang.Thread.run(Thread.java:748)
[error] (Test / executeTests) java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
所以问题似乎在于IntelliJ和sbt如何运行Scalatest。