如何模拟SQLiteOpenHelper

Question

null

@RunWith(AndroidJUnit4::class)
class ToDoListInstrumentedTest {

    @Rule
    @JvmField var activityRule: ActivityTestRule<MainActivity> = ActivityTestRule(MainActivity::class.java)

    private fun getActivity() = activityRule.activity

    @After
    fun tearDown() {
        InstrumentationRegistry.getInstrumentation().getTargetContext().deleteDatabase("TaskDatabase")
    }

    @Test
    fun oneTask() {
        val mock = mock(DatabaseHandler::class.java)
        `when`(mock.getTasks()).thenThrow()

        onView(withId(R.id.taskName)).check(matches(isDisplayed()))
    }
}

class DatabaseHandler(context: Context): SQLiteOpenHelper(context, DATABASE_NAME, null, DATABASE_VERSION) {
    companion object {
    private const val DATABASE_VERSION = 5
    private const val DATABASE_NAME = "TaskDatabase"
        ...
    }

    override fun onCreate(db: SQLiteDatabase?) {
        ...
    }

    override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
        ...
    }    
    fun getTasks(): MutableList<Pair<MutableList<String>, MutableList<Room>>> {
        ...
    }
}

我看过其他几个类似的问题，但没有一个有帮助：

• 模拟包含对SQLiteOpenHelper引用的类时出错
• 使用mockito库在java中模拟最终类-我在导入PowerMock时遇到了很多问题
• 如何用mockito模拟最后一个类-我已经添加了依赖项，并用mock-maker-inline行创建了文件，正如答案中所建议的那样，我仍然得到同样的错误。我还尝试了建议mockito.mock（somemockabletype.class,additionalanswers.delegatesto（someInstanceThatIsNotMockableOrSpyable))的答案，但这给了我一个‘没有足够的信息来推断类型变量t'error
• 用Mockito 2模拟最终类
• mockito不能mock/spy，因为：Final类
• 无法模拟/spy类java.util.optional

Answer 1

我会做一个界面：

public interface ContainerHandler {
    MutableList<Pair<MutableList<String>, MutableList<Room>>> getTasks();
}

然后让DatabaseHandler继承这个接口，用这个接口调用Mockito的mock函数。

val mock = mock(ContainerHandler::class.java)
    `when`(mock.getTasks()).thenThrow()

最后，我将我的模拟注入到测试类中。