NetworkOnMainThreadException

Hey. I know that there already is lot of similar issues but I cannot find solution. I’ve started working with Espresso UI tests. I prepare custom MockTestRunner, MockApplication for initialization Dagger components and I’ve defined mock modules too. It looks like that:

public class MockTestRunner extends AndroidJUnitRunner {
        public Application newApplication(ClassLoader cl, String className, Context context)
                throws InstantiationException, IllegalAccessException, ClassNotFoundException {
            return super.newApplication(cl, MockMyApplication.class.getName(), context);
        }
 }

MyApp is extended by

public class MockQrApplication extends MyApp {
    private MockWebServer mockWebServer;

    protected void initComponent() {
        mockWebServer = new MockWebServer();

        component = DaggerMyAppComponent
                .builder()
                .myAppModule(new MyAppModule(this))
                .busModule(new BusModule())
                .apiModule(new MockApiModule(mockWebServer))
                .facebookModule(new FacebookModule())
                .dataManagerModule(new DataManagerModule())
                .greenDaoModule(new GreenDaoModule())
                .trackModule(new TrackModule(this))
                .build();

        component.inject(this);
    }
}

I added testInstrumentationRunner into gradle

defaultConfig {
        ....
        multiDexEnabled true

        testInstrumentationRunner "a.b.c.MockTestRunner"
    }

I want run login tests in my LoginActivity

@RunWith(AndroidJUnit4.class)
@LargeTest
public class LoginActivityTest {
    protected Solo solo;

    @Rule
    public ActivityTestRule<LoginActivity> activityTestRule = new ActivityTestRule(LoginActivity.class);

    @Before
    public void setUp() throws Exception {
        initVariables();
    }

    protected void initVariables() {
        solo = new Solo(InstrumentationRegistry.getInstrumentation(), activityTestRule.getActivity());
    }

    @Test
    public void testLayout() {
        solo.waitForFragmentByTag(LoginFragment.TAG, 1000);

        onView(withId(R.id.email_input)).perform(clearText(), typeText("[e-mail]"));
        onView(withId(R.id.pass_input)).perform(clearText(), typeText("qqqqqqqq"));
        onView(withId(R.id.login_button)).perform(click());

        solo.waitForDialogToOpen();
    }
}

This is MockApiModule which extends ApiModule class

public class MockApiModule extends ApiModule {
    private MockWebServer mockWebServer;

    public MockApiModule(MockWebServer mockWebServer) {
        this.mockWebServer = mockWebServer;
    }

    @Override
    public OkHttpClient provideOkHttpClient(DataManager dataManager) {
        return new OkHttpClient.Builder()
                .build();
    }

    @Override
    public Retrofit provideRetrofit(OkHttpClient okHttpClient) {
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(mockWebServer.url("/"))       // throw NetworkOnMainThreadException
                .addConverterFactory(NullOnEmptyConverterFactory.create())
                .addConverterFactory(GsonConverterFactory.create(new Gson()))
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .client(okHttpClient)
                .build();
        return retrofit;
    }

    @Override
    public ApiService provideApiService(Retrofit retrofit) {
        return retrofit.create(ApiService.class);
    }

    @Override
    public ApiClient provideApiManager(Application application, ApiService apiService, DataManager dataManager) {
        return new MockApiClient(application, apiService, dataManager, mockWebServer);
    }
}

API login request looks like that:

public void login(UserLoginModel userLoginModel, final Account.Login callback) {
        final CountDownLatch latch = new CountDownLatch(1);

        mockWebServer.enqueue(MockResponse.getMockResponse(200, MockResponse.getResourceAsString(this, "login.json")));

        super.login(userLoginModel, new Account.Login() {
            @Override
            public void onLoginSuccess(LoginResponse response) {
                callback.onLoginSuccess(response);

                latch.countDown();
            }

            @Override
            public void onLoginFail(String message) {

            }
        });

        try {
            latch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

It works if I change MockMyApplication into MyApp class of application in MockTestRunner

When I want to run my tests I got:

android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1285)
at java.net.InetAddress.lookupHostByName(InetAddress.java:431)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getByName(InetAddress.java:305)
at okhttp3.mockwebserver.MockWebServer.start(MockWebServer.java:303)
at okhttp3.mockwebserver.MockWebServer.start(MockWebServer.java:293)
at okhttp3.mockwebserver.MockWebServer.maybeStart(MockWebServer.java:143)
at okhttp3.mockwebserver.MockWebServer.getHostName(MockWebServer.java:172)
at okhttp3.mockwebserver.MockWebServer.url(MockWebServer.java:198)
at com.mooduplabs.qrcontacts.modules.MockApiModule.provideRetrofit(MockApiModule.java:38)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideRetrofitFactory.get(ApiModule_ProvideRetrofitFactory.java:23)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideRetrofitFactory.get(ApiModule_ProvideRetrofitFactory.java:9)
at dagger.internal.ScopedProvider.get(ScopedProvider.java:46)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideApiServiceFactory.get(ApiModule_ProvideApiServiceFactory.java:23)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideApiServiceFactory.get(ApiModule_ProvideApiServiceFactory.java:9)
at dagger.internal.ScopedProvider.get(ScopedProvider.java:46)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideApiManagerFactory.get(ApiModule_ProvideApiManagerFactory.java:31)
at com.mooduplabs.qrcontacts.modules.ApiModule_ProvideApiManagerFactory.get(ApiModule_ProvideApiManagerFactory.java:11)
at dagger.internal.ScopedProvider.get(ScopedProvider.java:46)
at com.mooduplabs.qrcontacts.activities.BaseActivity_MembersInjector.injectMembers(BaseActivity_MembersInjector.java:44)
at com.mooduplabs.qrcontacts.activities.BaseActivity_MembersInjector.injectMembers(BaseActivity_MembersInjector.java:13)
at com.mooduplabs.qrcontacts.components.DaggerQrContactsAppComponent.inject(DaggerQrContactsAppComponent.java:91)
at com.mooduplabs.qrcontacts.activities.BaseActivity.init(BaseActivity.java:74)
at com.mooduplabs.qrcontacts.activities.BaseActivity.onCreate(BaseActivity.java:64)
at android.app.Activity.performCreate(Activity.java:6367)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
at android.support.test.runner.MonitoringInstrumentation.callActivityOnCreate(MonitoringInstrumentation.java:532)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2404)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2511)
at android.app.ActivityThread.access$900(ActivityThread.java:165)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1375)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:150)
at android.app.ActivityThread.main(ActivityThread.java:5621)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:684)

[RafalManka]

If anyone else stumbles on this problem here is the solution. Modify your custom AndroidJUnitRunner like so:

class EspressoRunner : AndroidJUnitRunner() {

    override fun onCreate(arguments: Bundle) {
        StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.Builder().permitAll().build())
        super.onCreate(arguments)
    }

    ...

}

copied from this article.

[DavidEdwards]

@rusmichal

If you are confused about threading, you should take a look at this:

http://stackoverflow.com/questions/6343166/how-to-fix-android-os-networkonmainthreadexception

There are some good explanations, and some solutions.