一个带有mockito测试的简单kotlin类导致了MissingMethodInvocationException

Question

我开始学习Kotlin和Mockito,所以我编写了一个简单的模块来测试它.

AccountData_K.kt:

open class AccountData_K {
var isLogin: Boolean = false
var userName: String? = null

    fun changeLogin() : Boolean {
        return !isLogin
    }
}

AccountDataMockTest_K.kt:

class AccountDataMockTest_K {
    @Mock
    val accountData = AccountData_K()

    @Before
    fun setupAccountData() {
        MockitoAnnotations.initMocks(this)
    }

    @Test
    fun testNotNull() {
        assertNotNull(accountData)
    }

    @Test
    fun testIsLogin() {
        val result = accountData.changeLogin()
        assertEquals(result, true)
    }

    @Test
    fun testChangeLogin() {        
        `when`(accountData.changeLogin()).thenReturn(false)
        val result = accountData.changeLogin()
        assertEquals(result, false)
    }
}

当我运行测试时,它会报告有关该testChangeLogin()方法的异常:

org.mockito.exceptions.misusing.MissingMethodInvocationException: 
when() requires an argument which has to be 'a method call on a mock'.
For example:
    when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
2. inside when() you don't call method on mock but on some other object.
3. the parent of the mocked class is not public.
   It is a limitation of the mock engine.

at com.seal.materialdesignwithkotlin.AccountDataMockTest_K.testChangeLogin(AccountDataMockTest_K.kt:57)
...

我怀疑为什么这个方法不是模拟的方法调用...

所以请帮助我,谢谢.

Answer 1

默认情况下,Kotlin的课程和成员都是最终的.Mockito无法模拟最终类和方法.要使用Mockito,您需要使用open您想要模拟的方法:

open fun changeLogin() : Boolean {
    return !isLogin
}

进一步阅读

• 可以在Kotlin中使用Mockito吗？
• 是否可以在没有开课的情况下使用Mockito和Kotlin？

PS.在我看来,只要你通过ISP保持接口很小,使用Mockito或其他模拟框架的测试代码很少比手写假货/存根更易读和易懂.