Kotlin:手动内联通用函数会产生不同的结果吗? [英] Kotlin: Manually inlining a generic function produce a different result?

问题描述

我有一个简单的测试班

class SimpleClassTest {

    private fun <T> anyObject(): T {
        return Mockito.anyObject<T>()
    }

    lateinit var simpleObject: SimpleClass
    @Mock lateinit var injectedObject: InjectedClass


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

    @Test
    fun testSimpleFunction() {
        simpleObject = SimpleClass(injectedObject)
        simpleObject.simpleFunction()

        verify(injectedObject).settingDependentObject(anyObject())
    }
}

它可以正常运行并通过.

It works fine and pass.

由于私有通用anyObject()函数仅使用一次，因此我决定对其进行内联(手动)，即不再需要该函数，因此我可以从中更改

Since the private generic anyObject() function is only used once, so I decide to inlining it (manually) i.e. remove the need of that function, whereby I change from

verify(injectedObject).settingDependentObject(anyObject())

到

verify(injectedObject).settingDependentObject(Mockito.anyObject<DependentClass>())

但是现在这个错误为 java.lang.IllegalStateException: Mockito.anyObject<DependentClass>() must not be null

However this now error as java.lang.IllegalStateException: Mockito.anyObject<DependentClass>() must not be null

我在将函数调用内联到直接语句时做错了什么

Anything I did wrong inlining the function call to a direct statement?

使用之间有什么区别

private fun <T> anyObject(): T {
    return Mockito.anyObject<T>()
}

及以下?

Mockito.anyObject<DependentClass>()

推荐答案

Mockito.anyObject()的来源:

/**
 * Matches anything, including null.
 * <p>
 * This is an alias of: {@link #any()} and {@link #any(java.lang.Class)}
 * <p>
 * See examples in javadoc for {@link Matchers} class
 * 
 * @return <code>null</code>.
 */
public static <T> T anyObject() {
    return (T) reportMatcher(Any.ANY).returnNull();
}

此方法为Mockito设置一些内部状态，然后继续返回null.由于您期望在settingDependentObject()方法中使用非空实例，因此运行时将失败.

This method sets some internal state for Mockito, and then proceeds to return null. Since you're expecting a non-null instance in your settingDependentObject() method, the runtime fails.

为什么您的第一种方法成功了，但是我不确定.将null投射到T 似乎可以，但对我而言不再有效.因此，我也无法使您的第一个实现成功.

Why your first method succeeded, however, I'm not sure. Casting null to T seemed to work a while ago, but it doesn't work for me anymore. For that matter, I can't get your first implementation to succeed either.

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