将模拟对象注入伴随对象字段

Question

我有一个这样的 Scala 类：

object MyClient {
  private lazy val theClient: TheClient = new TheClient()
}

class MyClient {
  import MyClient._

  var client = null // this is only for unittest

  def getSomethingFromTheClient() = {
    if (client == null) client = theClient 
    client.getSomething() + " from MyClient" 
  }
}

其中一些代码只是为了方便单元测试，我可以在其中模拟 TheClient 并将其注入 MyClient，如下所示（我正在使用 Mockito）：

val mockTheClient = mock[TheClient]
val testMyClient = new MyClient()
testMyClient.client = mockTheClient
testMyClient.getSomethingFromTheClient() shouldBe "blabla"

这可行，但看起来很难看。理想情况下，如果我可以将 mockTheClient 注入到伴随对象字段中，那就太好了。还是我错过了其他东西？

Answer 1

为什么不直接做依赖注入

例如

lazy val client: TheClient = new TheClient()

class MyClient(client: => TheClient) {
  def getSomethingFromTheClient() = {
    client.getSomething() + " from MyClient" 
  }
}

然后在中测试

val mockTheClient = mock[TheClient]
val testMyClient = new MyClient(mockTheClient)
testMyClient.getSomethingFromTheClient() shouldBe "blabla"