而不是混合特性“FlatSpecLike"：

class PingPongActorSpec extends TestKit(ActorSystem("PingPongActorSpec")) 
  with ImplicitSender with FlatSpecLike with Matchers with BeforeAndAfterAll  {
  override def withFixture(test: OneArgTest) = {}
}

我们需要混合特质“fixture.flatSpecLike"：

class PingPongActorSpec extends TestKit(ActorSystem("PingPongActorSpec")) 
  with ImplicitSender with fixture.FlatSpecLike with Matchers with BeforeAndAfterAll
  override def withFixture(test: OneArgTest) = {}
}

这解决了问题。

您需要使用org.scalatest. flatspec.

import org.scalatest.flatspec.FixtureFlatSpecLike

class PingPongActorSpec extends TestKit(ActorSystem("PingPongActorSpec")) 
      with ImplicitSender with FixtureFlatSpecLike with Matchers with BeforeAndAfterAll { ...

只需删除导入即可。OneArgTest是Suite trait中的内部保护trait，因此它可以在Suite的后代中使用，而无需导入。

class PingPongActorSpec extends TestKit(ActorSystem("PingPongActorSpec")) 
  with ImplicitSender with FlatSpecLike with Matchers with BeforeAndAfterAll {

  override def withFixture(test: OneArgTest) = {}
}