根据这个回答:https://dev59.com/y10a5IYBdhLWcg3wAEo3#30806548,我在项目中使用了Play的ExecutionContext。
最近我需要使用Mockito测试一些Play中的服务。以下是简化版本:
import scala.concurrent.{ Future, ExecutionContext }
import play.api.libs.concurrent.Execution.Implicits.defaultContext
case class Model(id: Int, name: String)
trait DAO {
def findAll(implicit ec: ExecutionContext): Future[List[Model]]
}
class Service(dao: DAO) {
def findAll: Future[List[Model]] = dao.findAll
}
测试:
import play.api.libs.concurrent.Execution.Implicits.defaultContext
// doesn't work when different ExecutionContext
// import scala.concurrent.ExecutionContext.Implicits.global
class FuturesTest extends PlaySpec with MockitoSugar with ScalaFutures {
"Service" should {
"return all future data" in {
val mockModel = Model(1, "name")
val mockDAO = mock[DAO]
when(mockDAO.findAll) thenReturn Future.successful(List(mockModel))
val service = new Service(mockDAO)
val futureData = service.findAll
whenReady(futureData) { data =>
data.map(_.name) must contain(mockModel.name)
}
}
}
}
注意test中的注释,当在Service中调用dao.findAll时,我会收到一个NullPointException
。起初我以为Mockito无法处理Scala的Futures,但我发现ExecutionContext
是问题所在。由于我不是并发专家,可以有人解释一下为什么会发生这种情况吗?