用PowerMock模拟私有方法

Question

我正在尝试测试下一种方法：

public void methodToTest() {
    // Other stuff
    privateMethod(false).execute(new Void[0]);
}

称为PrivateMethod：

private AsyncTask<Void, Void, CustomObject> privateMethod(final boolean renew) {
    AsyncTask<Void, Void, CustomObject> asyncTask = new AsyncTask<Void, Void, CustomObject>() {

        @Override
        protected CustomObject doInBackground(Void... params) {
            CustomObject custom = new CustomObject();

            return custom;
        }
        protected void onPostExecute(CustomObject custom) {
            //some code
        }
    };

asyncTask的执行无法在Mockito的测试中完成，所以我需要以某种方式模拟它。我试着用PowerMock来嘲弄私有方法：

@Mock Context mockContext;
@Mock AsyncTask<Void, Void, CustomObject> mockAsyncTask;

@Test
public void methodTest() {
    ClassToTest objectToTest = new ClassToTest(mockContext);
    try {
        PowerMockito.doReturn(mockAsyncTask).when(objectToTest, "privateMethod", ArgumentMatchers.anyBoolean());
    objectToTest.methodToTest();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

这在PowerMockito行（NullPointerException）中给了我一个异常，它说

方法引发了“org.mockito.exceptions.Misusing.UnfinishedStubbingException”异常。无法计算Android.os.AsyncTask$MockitoMock$1952591544.ToString（）

现在我已经没有办法模仿这个物体了。

Answer 1

我终于找到了答案：

@Test
public void methodTest() {
    ClassToTest objectToTest = PowerMockito.spy(new ClassToTest());
    try {
        when(objectToTest, method(ClassToTest.class, "privateMethod", boolean.class)).withArguments(false).thenReturn(mockAsyncTask);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

并且就在类声明之前：

@PrepareForTest(ClassToTest.class)