使用scalamock将模拟对象用作scala中的隐式对象

时间:2014-11-20 02:56:44

标签: scala unit-testing mocking scalatest scalamock

我正在使用具有各种具体衍生物的特征定义,并隐含地将依赖性注入对象,并在单元测试时模拟系统的各个部分。问题是当一个类型的模拟版本被用作隐式声明时,它与消费对象中的scala不匹配。

以下是我的设置的简化版本。有没有办法让 Test1 使用模拟工作。 Test2 工作正常,但很难维护,需要设置太多。

模特:

case class User (first: String, last: String, enabled: Boolean)

组件定义:

trait DataProviderComponent {
  def find[T](id: Int): Try[T]
  def update[T](data: T): Try[T]
}

具体组件实现之一:

class DbProvider extends DataProviderComponent {
  override def find[T](id: Int): Try[T] = { ... }
  override def update[T](data: T): Try[T] = { ... }
}

在系统的某处隐式使用组件impl:

implicit val provider = new DbProvider()

class UserRepsitory(implicit provider: DataProviderComponent) {
  def userEnabled(id: Int): Boolean = {
    val user = provider.find[User](id)
    user.isSuccess && user.get.enabled
  }
}

单元Test1,试图模拟提供程序以隔离存储库测试。这不起作用,尽管存储库类基于DataProviderComponent,但它与隐式类不匹配:

class UserRepository$Test1 extends FunSuite with Matchers with MockFactory {
  test("invalid data request should return false") {
    implicit val  mockProvider = mock[DataProviderComponent]
    (mockProvider.find[User] _).expects(13).returns(Failure[User](new Exception("Failed!")))

    val repo = new UserRepsitory()
    repo.userEnabled(13) should be (false)
  }
}

此版本确实有效,但很难维护,需要更多代码:

class UserRepository$Test2 extends FunSuite with Matchers with MockFactory {
  test("invalid data request should return false") {
    class FakeProvider extends DataProviderComponent {
      override def find[T](id: Int): Try[T] = ???
      override def update[T](data: T): Try[T] = Failure[T](new Exception("Failed!"))
    }

    implicit val provider = new FakeProvider()
    val repo = new UserRepsitory()
    repo.userEnabled(13) should be (false)
  }
}

有没有办法使用模拟类型作为注入隐式 - 或者是否有另一个scala-thonic模式我应该用来解决这个问题?

1 个答案:

答案 0 :(得分:2)

此代码成功编译并为我运行

scala:2.10.4

scalaTest:2.1.0-RC2

scalaMock:3.1.RC1

import org.scalamock.scalatest.MockFactory
import org.scalatest.{FunSuite, Matchers}

import scala.util.{Failure, Try}

case class User(first: String, last: String, enabled: Boolean)

trait DataProviderComponent {
  def find[T](id: Int): Try[T]

  def update[T](data: T): Try[T]
}

class DbProvider extends DataProviderComponent {
  override def find[T](id: Int): Try[T] = {
    ???
  }

  override def update[T](data: T): Try[T] = {
    ???
  }
}

class UserRepository(implicit provider: DataProviderComponent) {
  def userEnabled(id: Int): Boolean = {
    val user = provider.find[User](id)
    user.isSuccess && user.get.enabled
  }
}

class UserRepositoryTest extends FunSuite with Matchers with MockFactory {
  test("invalid data request should return false") {
    implicit val mockProvider: DataProviderComponent = mock[DataProviderComponent]
    (mockProvider.find[User] _).expects(13).returns(Failure[User](new Exception("Failed!")))

    val repo = new UserRepository()
    repo.userEnabled(13) should be(false)
  }
}