如何使用 Robolectric 测试 IntentService？

我正在尝试测试onHandleIntent()的方法IntentService using Robolectric.

我正在启动该服务：

Activity activity = new Activity();
Intent intent = new Intent(activity, MyService.class);
activity.startService(intent);

ShadowActivity shadowActivity = Robolectric.shadowOf(activity);
Intent startedIntent = shadowActivity.getNextStartedService();
assertNotNull(startedIntent);

似乎startedIntent不为空，但是onHandleIntent()似乎没有被调用。

我应该如何测试它？

Robolectric 有一个ServiceController https://github.com/robolectric/robolectric/blob/robolectric-3.0/robolectric/src/main/java/org/robolectric/util/ServiceController.java它可以像活动一样贯穿服务生命周期。该控制器提供了执行相应服务回调的所有方法（例如controller.attach().create().startCommand(0, 0).destroy()).

理论上我们可以预期IntentService.onStartCommand() https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/java/android/app/IntentService.java#130将触发IntentService.onHandleIntent(Intent)，通过其内部Handler。然而这Handler uses a Looper它在后台线程上运行，我不知道如何使该线程前进到下一个任务。解决方法是创建TestService模仿相同的行为，但触发onHandleIntent(Intent)在主线程上（用于运行测试的线程）。

@RunWith(RobolectricGradleTestRunner.class)
public class MyIntentServiceTest {
    private TestService service;
    private ServiceController<TestService> controller;

    @Before
    public void setUp() {
        controller = Robolectric.buildService(TestService.class);
        service = controller.attach().create().get();
    }

    @Test
    public void testWithIntent() {
        Intent intent = new Intent(RuntimeEnvironment.application, TestService.class);
        // add extras to intent
        controller.withIntent(intent).startCommand(0, 0);
        // assert here
    }

    @After
    public void tearDown() {
        controller.destroy();
    }

    public static class TestService extends MyIntentService {
        public boolean enabled = true;

        @Override
        public void onStart(Intent intent, int startId) {
            // same logic as in internal ServiceHandler.handleMessage()
            // but runs on same thread as Service
            onHandleIntent(intent);
            stopSelf(startId);
        }
    }
}

UPDATE：或者，为 IntentService 创建类似的控制器也非常简单，如下所示：

public class IntentServiceController<T extends IntentService> extends ServiceController<T> {
    public static <T extends IntentService> IntentServiceController<T> buildIntentService(Class<T> serviceClass) {
        try {
            return new IntentServiceController<>(Robolectric.getShadowsAdapter(), serviceClass);
        } catch (IllegalAccessException | InstantiationException e) {
            throw new RuntimeException(e);
        }
    }

    private IntentServiceController(ShadowsAdapter shadowsAdapter, Class<T> serviceClass) throws IllegalAccessException, InstantiationException {
        super(shadowsAdapter, serviceClass);
    }

    @Override
    public IntentServiceController<T> withIntent(Intent intent) {
        super.withIntent(intent);
        return this;
    }

    @Override
    public IntentServiceController<T> attach() {
        super.attach();
        return this;
    }

    @Override
    public IntentServiceController<T> bind() {
        super.bind();
        return this;
    }

    @Override
    public IntentServiceController<T> create() {
        super.create();
        return this;
    }

    @Override
    public IntentServiceController<T> destroy() {
        super.destroy();
        return this;
    }

    @Override
    public IntentServiceController<T> rebind() {
        super.rebind();
        return this;
    }

    @Override
    public IntentServiceController<T> startCommand(int flags, int startId) {
        super.startCommand(flags, startId);
        return this;
    }

    @Override
    public IntentServiceController<T> unbind() {
        super.unbind();
        return this;
    }

    public IntentServiceController<T> handleIntent() {
        invokeWhilePaused("onHandleIntent", getIntent());
        return this;
    }
}