Play Framework2.5测试ApplicationLifecycle指南Specs2设置

Question

我正在尝试用play2-reactivemongo运行一些功能测试。我会尽量具体，但如果有什么遗漏，请让我知道。

我的依赖项在这里

libraryDependencies ++= Seq(
  cache,
  "org.reactivemongo" %% "play2-reactivemongo" %  "0.12.0",
  "com.mohiva" %% "play-silhouette" % "4.0.0",
  "com.mohiva" %% "play-silhouette-testkit" % "4.0.0" % "test",
  specs2 % Test
)

在MongoUserDao.scala中

import play.modules.reactivemongo._
import play.modules.reactivemongo.json._
import reactivemongo.play.json.collection.JSONCollection

class MongoUserDao @Inject() (val reactiveMongoApi: ReactiveMongoApi) extends UserDao {
  val usersFuture = reactiveMongoApi.database.map(_.collection[JSONCollection]("users"))
...
}

在DaoSpecResources.scala中

trait DaoSpecResources {

  val timeout = DurationInt(10).seconds

  val fakeApp = new GuiceApplicationBuilder()
    .in(Mode.Test)
    .configure(
      "play.modules.enabled" -> List("play.modules.reactivemongo.ReactiveMongoModule"),
      "mongodb.uri" -> "mongodb://localhost:27017/test"
    )
    .build

  val reactiveMongoApi = fakeApp.injector.instanceOf[ReactiveMongoApi]
  ...
}

当我尝试运行测试时，我得到了这个错误

[error] cannot create an instance for class daos.UserDaoSpec
[error]   caused by com.google.inject.CreationException: Unable to create injector, see the following errors:
[error]
[error] 1) No implementation for play.api.inject.ApplicationLifecycle was bound.
[error]   while locating play.api.inject.ApplicationLifecycle
[error]     for parameter 1 at services.ApplicationTimer.<init>(ApplicationTimer.scala:24)
[error]   at Module.configure(Module.scala:23) (via modules: com.google.inject.util.Modules$OverrideModule -> Module)
[error]
[error] 1 error

Answer 1

这是由app/services/ApplicationTimer.scala引起的，它依赖于ApplicationLifecycle，但是您还没有将任何实现绑定到ApplicationLifecycle。ApplicationTimer是每个新的Play项目中都包含的一个演示。如果不需要它，您可能应该将其完全删除，否则，如果在测试模式下运行，则至少将其禁用。参见disabling modules和overriding modules。

解决方案

但是，由于DefaultReactiveMongoApi也依赖于ApplicationLifecycle，因此您需要提供到ApplicationLifecycle实现的绑定。最简单的方法：

import play.api.inject.{ ApplicationLifecycle, DefaultApplicationLifecycle }
import play.api.inject.bind

trait DaoSpecResources {

  val timeout = DurationInt(10).seconds

  val fakeApp = new GuiceApplicationBuilder()
    .in(Mode.Test)
    .configure(
      "play.modules.enabled" -> List("play.modules.reactivemongo.ReactiveMongoModule"),
      "mongodb.uri" -> "mongodb://localhost:27017/test"
    )
    .bindings(bind[ApplicationLifecycle].to[DefaultApplicationLifecycle])
    .build

  val reactiveMongoApi = fakeApp.injector.instanceOf[ReactiveMongoApi]

  val lifecycle = fakeApp.injector.instanceOf[DefaultApplicationLifecycle]
  def stopApp = lifecycle.stop()

}

(新增5行: imports、bindings、lifecycle、stopApp)

然后，在测试规范的末尾添加step(stopApp)，如下所示：

class FooSpec extends PlaySpecification with DaoSpecResources {

    // Your examples...

    step(stopApp)

}

替代解决方案

就我个人而言，我会创建一个专门的特征来扩展Specification或PlaySpecification，它会自动设置和拆卸所有东西，比如in this example from specs2 documentation。

trait PlayWithMongoSpecification extends PlaySpecification {

  val timeout = DurationInt(10).seconds

  val fakeApp = new GuiceApplicationBuilder()
    .in(Mode.Test)
    .configure(
      "play.modules.enabled" -> List("play.modules.reactivemongo.ReactiveMongoModule"),
      "mongodb.uri" -> "mongodb://localhost:27017/test"
    )
    .bindings(bind[ApplicationLifecycle].to[DefaultApplicationLifecycle])
    .build

  val reactiveMongoApi = fakeApp.injector.instanceOf[ReactiveMongoApi]

  val lifecycle = fakeApp.injector.instanceOf[DefaultApplicationLifecycle]
  def stopApp = lifecycle.stop()

  override def map(fs: =>Fragments) = fs ^ step(stopApp)

}

class FooSpec extends PlayWithMongoSpecification {

    // Your examples...

}

您可以考虑将reactiveMongoApi设置为lazy val。