android - 使用 Mockito-Kotlin 模拟的上下文在定义调用 getSharedPreferences 时的操作后返回一个空 SharedPreferences 实例

Question

我有以下测试类：

@RunWith(MockitoJUnitRunner::class)
class RegistrationDataProviderUnitTest {

    private val mMockContext: Context = mock {
        on { getString(R.string.is_device_registered_key) } doReturn "is_device_registered_key"
        on {
            getSharedPreferences(
                anyString(), anyInt()
            )
        } doReturn mMockSharedPreferences
    }
    private val mMockSharedPreferences: SharedPreferences = mock {
        on {
            getBoolean(
                mMockContext.getString(R.string.is_device_registered_key), false
            )
        } doReturn true
        on {
            edit()
        } doReturn mMockSharedPreferencesEditor
    }
    private val mMockSharedPreferencesEditor: SharedPreferences.Editor = mock()
    private val okHttpClient: OkHttpClient = mock()
    private val analyticsService: AnalyticsService = mock()
    private val mRegistrationDataProvider =
        RegistrationDataProvider(mMockContext, okHttpClient, analyticsService)

    @Test
    fun registrationDataProvider_CheckIfDeviceIsRegistered() {
        val success: Boolean = mRegistrationDataProvider.checkIfDeviceIsRegistered()
        MatcherAssert.assertThat(
            "Checking that we retrieved the value of the shared preference key for when device is registered",
            success
        )
    }
}

我在模拟上下文，并在调用 getSharedPreferences 时传递了一个模拟共享首选项。

然后我将上下文传递给我的 RegistrationDataProvider 类。这是该类的外观：

class RegistrationDataProvider @Inject constructor(
    @ApplicationContext private val appContext: Context,
    private val okHttpClient: OkHttpClient,
    private val analyticsService: AnalyticsService
) {

    fun checkIfDeviceIsRegistered(): Boolean {
        println(appContext)
        val sharedPref = appContext.getSharedPreferences(
            appContext.getString(R.string.shared_preferences_key),
            Context.MODE_PRIVATE
        )
        println(sharedPref)
        return sharedPref.getBoolean(
            appContext.getString(R.string.is_device_registered_key),
            false
        )
    }
}

当我调用时，我期望mRegistrationDataProvider.checkIfDeviceIsRegistered()的是正在使用的共享首选项是 mMockSharedPreferences 的一个实例，但是我得到的只是null。

如您所见，我的checkIfDeviceIsRegistered()函数中有两个打印语句，其中appContext返回mMockContext，sharedPref返回null。

为什么返回 null 以及如何修改测试以返回正确的值？