ScalaTest,Mockito,Guice和PartialMocking

Question

我正在使用Google Guice作为DI框架,我正在为使用Google Guice的课程编写单元测试.我也试图做部分嘲笑.

这是我写的代码

class Test1 {
   def test1() = "I do test1"
}
class Test2 {
   def test2() = "I do test2"
}
class TestPartialMock @Inject()(t1: Test1, t2: Test2) {
   def test3() = "I do test3"
   def createList() : List[String] = List(t1.test1(), t2.test2(), test3())
}

我的目标是为上面的代码编写测试用例,但我只想模拟 test3

我写了这个测试用例

class TestModule extends AbstractModule with ScalaModule with MockitoSugar {
   override def configure() = {
      bind[Test1]
      bind[Test2]
      val x = mock[TestPartialMock]
      when(x.test3()).thenReturn("I am mocked")
      when(x.createList()).thenCallRealMethod()
      bind(classOf[TestPartialMock]).toInstance(x)
   }
}

class PartialMockTest extends FunSpec with Matchers {
   describe("we are testing workhorse but mock test3") {
      it("should return mock for test3") {
         val module = new TestModule
         val injector = Guice.createInjector(module)
         val tpm = injector.getInstance(classOf[TestPartialMock])
         val result = tpm.workHorse()
         result should contain ("I do test2")
         result should contain ("I do test1")
         result should contain ("I am mocked")
         result should not contain ("I do test3")
      }
   }
}

但是,依赖项上的空指针异常测试失败(调用t1)

java.lang.NullPointerException
    at TestPartialMock.createList(TestPartialMock.scala:9)
    at PartialMockTest.$anonfun$new$2(PartialMockTest.scala:16)
    at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
    at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
    at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
    at org.scalatest.Transformer.apply(Transformer.scala:22)
    at org.scalatest.Transformer.apply(Transformer.scala:20)
    at org.scalatest.FunSpecLike$$anon$1.apply(FunSpecLike.scala:454)

那么如何将注入的依赖项与模拟test3方法一起使用呢？

如果您需要查看这些依赖项,请参阅以下内容

"net.codingwell" %% "scala-guice" % "4.1.0",
"org.scalatest" % "scalatest_2.12" % "3.0.3",
"org.scalamock" % "scalamock-scalatest-support_2.12" % "3.5.0",
"org.mockito" % "mockito-core" % "2.7.22"

Answer 1

诀窍在于,当创建模拟对象时,Mockito不会调用(基类)类的构造函数.因此,TestPartialMock未初始化的依赖性.解决这个问题的最简单方法是监视一个你可以用你想要的任何配置创建的真实对象

class TestModule extends AbstractModule with ScalaModule with MockitoSugar {
  override def configure() = {
    //bind[Test1]
    //bind[Test2]
    //val x = mock[TestPartialMock]
    val realObject = new TestPartialMock(new Test1, new Test2)
    val x = spy(realObject)
    when(x.test3()).thenReturn("I am mocked")
    when(x.createList()).thenCallRealMethod()
    bind(classOf[TestPartialMock]).toInstance(x)
  }
}