Espresso.pressBack() does not call onBackPressed()

问题:

In Espresso class:

 @Rule
    public IntentsTestRule<MainActivity> mIntentsRule = new IntentsTestRule<>(
            MainActivity.class);

@Test
public void test_backButton(){
onView(withId(R.id.NEXT_ACTIVITY)).perform(scrollTo(), click());

Espresso.pressBack();
}

In Activity:

 @Override
public void onBackPressed() {
    Log.d("TEST_pressBack", "inside onBackPressed()");
    do_something();
    super.onBackPressed();

}
   @Override
public void finish() {
    Log.d("TEST_pressBack", "inside finish()");
    super.finish();

}

When I call the Espresso test method the execution goes directly to finish().

When I press the back button (with my hand) in the Activity the execution goes firstly in onBackPressed() and then to finish(). How can I test the function onBackPressed() with Espresso? Thanks!

EDIT: It is my error. The problem was that in Activity in which I wanted to call pressBack the onscreen keyboard was opened. When the soft keyboard is open then the press-button does not call onBackPressed but instead makes the keyboard non-displayed. I tried with two pressBack() in a row and it worked correctly:

    @Rule
    public IntentsTestRule<MainActivity> mIntentsRule = new IntentsTestRule<>(
            MainActivity.class);

@Test
public void test_backButton(){
onView(withId(R.id.NEXT_ACTIVITY)).perform(scrollTo(), click());

Espresso.pressBack();

//The extra pressBack()
Espresso.pressBack();

}

回答1:

It looks like the Espresso.pressBack() method does just work the way you expect it if you are not in the root activity. When you take a look at it's implementation comment:

  /**
  * Press on the back button.
  *
  * @throws PerformException if currently displayed activity is root activity, since pressing back
  *         button would result in application closing.
  */
  public static void pressBack() {
        onView(isRoot()).perform(ViewActions.pressBack());
  }

I tested it and it works fine if you are doing this in an activity that is not your root activity. If you want to do it there, I would suggest you use ui-automator instead (ui-automator is perfectly usable inside espresso tests):

Add this to your gradle:

androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'

And then do this in your test:

UiDevice mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());
mDevice.pressBack();

回答2:

@billst you are right, i too had the same problem with soft keyboard open, i debugged after reading your comment and better solution would be to use ViewAction.closeSoftKeyboard() instead of using back press twice.

@Test
public void afterStartedEditing_dialogDisplayed_when_home_or_back_pressed() {
    //find view
    onView(withId(R.id.add_pet_breed))
            .perform(click())
            .perform(closeSoftKeyboard());
    onView(isRoot()).perform(pressBack());

    //check assertion
    onView(withText(R.string.discard))
            .check(matches(isDisplayed()));
}