Android Espresso how to write tests using apk?

问题

I am a robotium user now switching to Espresso can anyone tell me how to write tests using apk in espresso, as we do in robotium without having acccess to the code but using app apk.

And how to access views without R.id.viewid in espresso? as we do in robotium

solo.getview("viewidText")

In robotium this is how we do

public class CoreTest extends ActivityInstrumentationTestCase2 {
private Solo solo;

//class name of the app launcher activity
private static final String LAUNCHER_ACTIVITY_FULL_CLASSNAME = "com.rex.binderapps.RecorderActivity";


private static Class<?> launcherActivityClass;

static {
    try {
        launcherActivityClass = Class.forName(LAUNCHER_ACTIVITY_FULL_CLASSNAME);
    } catch (ClassNotFoundException e) {
        throw new RuntimeException(e);
    }
}

@SuppressWarnings("unchecked")
public CoreRecordingTest() throws ClassNotFoundException {
    super(launcherActivityClass);
}

public void setUp() throws Exception {
    super.setUp();
    solo = new Solo(getInstrumentation());
    Test.setup(this);
    getActivity();
}

@Override
public void tearDown() throws Exception {
    solo.finishOpenedActivities();
    super.tearDown();
}
...

In espresso

 @RunWith(AndroidJUnit4.class)
public class MainActivityTest {

// RecorderActivity is not accessible
@Rule public final ActivityRule<RecorderActivity> main = new ActivityRule<>(RecorderActivity.class);

@Test
public void launchMain(){

  }
}

How to specify the class name?

回答1:

You can use the same reflection technique to specify the class in ActivityTestRule:

@RunWith(AndroidJUnit4.class)
public class MainActivityTest {

  private static final String CLASSNAME = "com.rex.binderapps.RecorderActivity";

  private static Class<? extends Activity> activityClass;
  static {
    try {
      activityClass = (Class<? extends Activity>) Class.forName(CLASSNAME);
    } catch (ClassNotFoundException e) {
      throw new RuntimeException(e);
    }
  }

  @Rule 
  public final ActivityTestRule<?> activityRule 
      = new ActivityTestRule<>(activityClass);

  @Test
  public void launchMain() {

  }
}

来源：https://stackoverflow.com/questions/29895691/android-espresso-how-to-write-tests-using-apk