Specs2：如何测试具有多个注入依赖关系的类？ [英] Specs2: how to test a class with more than one injected dependency?

问题描述

播放2.4应用程序，使用依赖注入服务类

Play 2.4 app, using dependency injection for service classes.

我发现当测试的服务类有多个注入的依赖项时，Specs2阻塞。它失败了找不到类... 的构造函数

I found that Specs2 chokes when a service class being tested has more than one injected dependency. It fails with "Can't find a constructor for class ..."

$ test-only services.ReportServiceSpec
[error] Can't find a constructor for class services.ReportService
[error] Error: Total 1, Failed 0, Errors 1, Passed 0
[error] Error during tests:
[error]         services.ReportServiceSpec
[error] (test:testOnly) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 2 s, completed Dec 8, 2015 5:24:34 PM

生产代码这个问题：

package services

import javax.inject.Inject

class ReportService @Inject()(userService: UserService, supportService: SupportService) {  
   // ...  
}

class UserService {  
   // ...  
}

class SupportService {  
   // ...  
}

测试代码：

package services

import javax.inject.Inject

import org.specs2.mutable.Specification

class ReportServiceSpec @Inject()(service: ReportService) extends Specification {

  "ReportService" should {
    "Work" in {
      1 mustEqual 1
    }
  }

}

如果我从 ReportService 中删除​​ UserService 或 SupportService ，测试工作。但显然，依赖关系在生产代码中是一个原因。 问题是，如何使此测试工作？

If I remove either UserService or SupportService dependency from ReportService, the test works. But obviously the dependencies are in the production code for a reason. Question is, how do I make this test work?

编辑：尝试在IntelliJ中运行测试IDEA，同样的事情失败，但有不同的消息：测试框架意外退出，这看起来像一个specs2异常...;请参阅使用堆栈跟踪完整输出。我按照输出中的说明打开了Specs2 问题，尽管我不知道是否有问题在Play或Specs2或其他地方。

Edit: When trying to run the test inside IntelliJ IDEA, the same thing fails, but with different messages: "Test framework quit unexpectedly", "This looks like a specs2 exception..."; see full output with stacktrace. I opened a Specs2 issue as instructed in the output, though I have no idea if the problem is in Play or Specs2 or somewhere else.

我的库依赖关系如下。 （我尝试指定Specs2版本明确，但这没有帮助。看起来我需要 specs2％Test ，因为Play的测试类，如 WithApplication 可以正常工作。）

My library dependencies below. (I tried specifying Specs2 version explicitly, but that didn't help. Looks like I need specs2 % Test as is, for Play's test classes like WithApplication to work.)

resolvers += "scalaz-bintray" at "https://dl.bintray.com/scalaz/releases"
libraryDependencies ++= Seq(
  specs2 % Test,
  jdbc,
  evolutions,
  filters,
  "com.typesafe.play" %% "anorm" % "2.4.0",
  "org.postgresql" % "postgresql" % "9.4-1205-jdbc42"
)

推荐答案

在specs2中对依赖注入的支持有限，主要是执行环境或命令行参数。

There is limited support for dependency injection in specs2, mostly for execution environments or command-line arguments.

没有什么可以阻止你使用 lazy val 和你最喜欢的注入框架：

There is nothing preventing you from just using a lazy val and your favourite injection framework:

class MySpec extends Specification with Inject {
  lazy val reportService = inject[ReportService]

  ...
}

通过 Play和Guice ，您可以有一个测试助手如下所示：

With Play and Guice, you could have a test helper such as this:

import play.api.inject.guice.GuiceApplicationBuilder
import scala.reflect.ClassTag    

trait Inject {
  lazy val injector = (new GuiceApplicationBuilder).injector()

  def inject[T : ClassTag]: T = injector.instanceOf[T]
}

这篇关于Specs2：如何测试具有多个注入依赖关系的类？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！