如何在控制器中执行单元测试？

Question

假设，我有如下控制器：

class JenisKejahatanControl @Inject()(service: JenisKejahatanService, val messagesApi: MessagesApi) extends Controller with I18nSupport {

  def add = Action.async { implicit request =>
    lazy val incoming = JenisKejahatan.formJenisK.bindFromRequest()

    incoming.fold( error => {
      lazy val response = ErrorResponse(BAD_REQUEST, messagesApi("request.error"))
      Future.successful(BadRequest(Json.toJson(response)))
    }, { newJenisK =>
      lazy val future = service.addJenisK(newJenisK)
      future.flatMap {
        case Some(jenis) => Future.successful(Created(Json.toJson(SuccessResponse(jenis))))
        case None => Future.successful(BadRequest(Json.toJson(ErrorResponse(NOT_FOUND, messagesApi("add.jenis.kejahatan.fail")))))
      }
    })
  }
}

我想使用 specs2 测试我的 def add，怎么做？

Answer 1

由于您的控制器已注入组件，因此我认为您缺少的一点是如何在满足各种依赖关系的规范中获取它的实例。为此，您可以使用 GuiceApplicationBuilder 获取 Play 应用程序实例，然后使用其 injector 获取控制器的实例，而无需手动构建它（更多依赖注入文档 here，特别是关于使用 Guice 进行测试here.)

如果您可以像示例中那样手动构建控制器，那很好，并且使事情变得更简单，但是控制器往往具有非平凡的依赖关系，您很可能希望使用 @987654328 上的 overrides 方法来模拟这些依赖关系@。

通过构造控制器的实例，将模拟（假）请求“应用”到您的操作方法并确定它们提供您期望的状态和主体非常简单。这是一个例子：

import controllers.{SuccessResponse, JenisKejahatanControl}
import play.api.inject.guice.GuiceApplicationBuilder
import play.api.inject.bind
import play.api.mvc.Result
import play.api.test.{FakeRequest, PlaySpecification}

import scala.concurrent.Future

class JenisKejahatanControlSpec extends PlaySpecification {

  "JenisKejahatanControl#add" should {
    "be valid" in {

      // Build an instance of a Play application using the
      // default environment and configuration, and use it
      // to obtain an instance of your controller with the
      // various components injected.
      val jenisController = new GuiceApplicationBuilder()
        .overrides(  // Mock the data service
          bind[JenisKejahatanService]
           .toInstance(new MockJenisKejahatanService))
        .build()
        .injector
        .instanceOf[JenisKejahatanControl]

      // Create a "fake" request instance with the appropriate body data
      val request = FakeRequest().withFormUrlEncodedBody("name" -> "test")

      // Apply the request to your action to obtain a response
      val eventualResult: Future[Result] = jenisController.add.apply(request)

      // Check the status of the response
      status(eventualResult) must_== CREATED

      // Ensure the content of the response is as-expected
      contentAsJson(eventualResult).validate[SuccessResponse].asOpt must beSome.which { r =>
        r.jenis.name must_== "test"
      }
    }
  }
}