Scala / specs2：找不到类型为 AsExecution[ExecutionEnv => MatchResult[Future[AuthenticationResult]]] 的证据参数的隐式值

Question

我正在尝试将 Scala/Play 应用程序升级到 Play 2.7、Scala 2.12.11。

我有以下测试，在我升级 Play 和 Scala 之前，它可能曾经有效。

升级后出现如下编译错误：

Error: could not find implicit value for evidence parameter of type org.specs2.specification.core.AsExecution[org.specs2.concurrent.ExecutionEnv => org.specs2.matcher.MatchResult[scala.concurrent.Future[services.AuthenticationResult]]]

import org.specs2.concurrent.ExecutionEnv
import org.specs2.mutable.Specification

import scala.concurrent.duration._

class AuthenticationServiceSpec extends Specification {

  "The AuthenticationService" should {

    val service: AuthenticationService = new MyAuthenticationService

    "correctly authenticate Me" in { implicit ee: ExecutionEnv =>
      service.authenticateUser("myname", "mypassowrd") must beEqualTo (AuthenticationSuccessful).await(1, 200.millis)
    }

  }

}

为了尝试解决编译错误，我在 class 构造函数中添加了一个隐式参数（顺便说一句，之前它是如何工作的，没有隐式参数？）：

import org.specs2.concurrent.ExecutionEnv
import org.specs2.mutable.Specification

import scala.concurrent.duration._
import scala.concurrent.Future

import org.specs2.specification.core.AsExecution
import org.specs2.matcher.MatchResult    

class AuthenticationServiceSpec(implicit ee: AsExecution[ExecutionEnv => MatchResult[Future[AuthenticationResult]]]) extends Specification {

  "The AuthenticationService" should {

    val service: AuthenticationService = new MyAuthenticationService

    "correctly authenticate Me" in { implicit ee: ExecutionEnv =>
      service.authenticateUser("myname", "mypassowrd") must beEqualTo (AuthenticationSuccessful).await(1, 200.millis)
    }

  }

}

但是在运行测试时运行出现错误：

Can't find a suitable constructor with 0 or 1 parameter for class org.specs2.specification.core.AsExecution

基于AsExecution的构造函数，有道理...

那我该如何解决这个问题呢？

Answer 1

这应该有效

class AuthenticationServiceSpec(implicit ee: ExecutionEnv) extends Specification {

  "The AuthenticationService" should {

    val service: AuthenticationService = new MyAuthenticationService

    "correctly authenticate Me" in {
      service.authenticateUser("myname", "mypassword") must beEqualTo (AuthenticationSuccessful).await(1, 200.millis)
    }

  }

}

ee: ExecutionEnv 将在构建规范时直接注入。

这就是消息的意思Can't find a suitable constructor with 0 or 1 parameter for class ...。 specs2 尝试为规范递归构建参数，如果它们具有带 0 或 1 个参数的构造函数。 ExecutionEnv 是这样一个论点，specs2 能够自行构建。

Scala / specs2：找不到类型为 AsExecution[ExecutionEnv => MatchResult[Future[AuthenticationResult]]] 的证据参数的隐式值

Scala / specs2 : could not find implicit value for evidence parameter of type AsExecution[ExecutionEnv => MatchResult[Future[AuthenticationResult]]]

scala

playframework

implicit

specs2