如何在Kotlin中模拟和验证Lambda表达? [英] How to mock and verify Lambda expression in Kotlin?

问题描述

在Kotlin(和Java 8)中，我们可以使用Lambda表达式删除样板回调接口.例如，

In Kotlin (and Java 8) we can use Lambda expression to remove boilerplate callback interface. For example,

data class Profile(val name: String)

interface ProfileCallback {
  fun onSuccess(profile: Profile)
}

class ProfileRepository(val callback: ProfileCallback) {

  fun getProfile() {
    // do calculation
    callback.onSuccess(Profile("name"))
  }
}

我们可以更改删除ProfileCallback并将其更改为Kotlin的Lambda:

We can change remove ProfileCallback and change it into Kotlin's Lambda:

class ProfileRepository(val callback: (Profile) -> Unit) {

  fun getProfile() {
    // do calculation
    callback(Profile("name"))
  }
}

这可以正常工作，但是我不确定如何模拟然后验证该功能.我有 尝试像这样使用Mockito

This works fine, but I'm not sure how to mock and then verify that function. I have tried using Mockito like this

@Mock
lateinit var profileCallback: (Profile) -> Unit

@Test
fun test() {
    // this wouldn't work
    Mockito.verify(profileCallback).invoke(any())   
}

但它抛出异常:

org.mockito.exceptions.base.MockitoException:ClassCastException 在创建模仿者嘲笑:模仿的类时发生: 'kotlin.jvm.functions.Function1'，由classloader加载: 'sun.misc.Launcher$AppClassLoader@7852e922'

org.mockito.exceptions.base.MockitoException: ClassCastException occurred while creating the mockito mock : class to mock : 'kotlin.jvm.functions.Function1', loaded by classloader : 'sun.misc.Launcher$AppClassLoader@7852e922'

如何在Kotlin中模拟和验证Lambda表达?甚至有可能吗?

How to mock and verify Lambda expression in Kotlin? Is it even possible?

推荐答案

以下是使用mockito-kotlin的示例:

给出存储库类

class ProfileRepository(val callback: (Int) -> Unit) {

    fun getProfile() {
        // do calculation
        callback(1)
    }
}

使用mockito-kotlin lib-您可以像这样编写测试模拟lambda:

Using mockito-kotlin lib - you can write test mocking lambdas like this:

@Test
fun test() {
    val callbackMock: (Int) -> Unit = mock()
    val profileRepository = ProfileRepository(callbackMock)

    profileRepository.getProfile()

    argumentCaptor<Int>().apply {
        verify(callbackMock, times(1)).invoke(capture())
        assertEquals(1, firstValue)
    }
}

这篇关于如何在Kotlin中模拟和验证Lambda表达?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！