Espresso How to access views without using R.id.viewid as we do in robotium?

Issue

I am switching from robotium to espresso, I am writing tests using apk, I dont have access to code. In robotium using solo.getView("view-id") we can access the view but I am not geting how to do it in espresso? espresso witId() method needs R.id.viewid which I dont have access.

public class AaEspressoTest {

private static final String LAUNCHER_ACTIVITY_FULL_CLASSNAME = "com.tri.re.CordActivity";
private static Class<?> launcherActivityClass;

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

@Rule
public ActivityTestRule<?> mActivityRule = new ActivityTestRule(launcherActivityClass);


@Test public void testHello() throws Exception{

    onView(withText("Browse older recordings")).perform(click());

   //Id is not accessible shows red
    onView(withId(R.id.button)).perform(click());

}

}

Solution

You can use a helper function to get the id:

private static int getId(String id) {
  Context targetContext = InstrumentationRegistry.getTargetContext();
  String packageName = targetContext.getPackageName();
  return targetContext.getResources().getIdentifier(id, "id", packageName);
}

Then you can use the id in Espresso:

onView(withId(getId("button"))).perform(click());

Answered By - chiuki