Checking toast message in android espresso

Question

Would anyone know how to test for the appearance of a Toast message in android espresso? In robotium its easy & I used but started working in espresso but dont getting the exact command.

Answer 1

I write my custom toast matcher:

import android.view.WindowManager
import androidx.test.espresso.Root
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;
class ToastMatcher : TypeSafeMatcher<Root>() {

    override fun describeTo(description: Description) {
        description.appendText("is toast")
    }

    override fun matchesSafely(root: Root): Boolean {
        val type = root.getWindowLayoutParams().get().type
        if (type == WindowManager.LayoutParams.TYPE_TOAST) {
            val windowToken = root.getDecorView().getWindowToken()
            val appToken = root.getDecorView().getApplicationWindowToken()
            if (windowToken === appToken) {
                return true
            }
        }
        return false
    }
}

And use like this:

onView(withText(R.string.please_input_all_fields)).inRoot(ToastMatcher()).check(matches(isDisplayed()))

Answer 2

This slightly long statement works for me:

import static android.support.test.espresso.assertion.ViewAssertions.matches;
import static android.support.test.espresso.matcher.RootMatchers.withDecorView;
import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.withText;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.not;
....
onView(withText(R.string.TOAST_STRING)).inRoot(withDecorView(not(is(getActivity().getWindow().getDecorView())))).check(matches(isDisplayed()));

Answer 3

I would say for toast messages first define your rule

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

then whatever toast message text you are looking for type it in between quotation for example I used "Invalid email address"

   onView(withText("Invalid email address"))
    .inRoot(withDecorView(not(activityTestRule.getActivity().getWindow().getDecorView())))
    .check(matches(isDisplayed()));

Answer 4

If you're using the newest Android Testing Tools from Jetpack, you know, that ActivityTestRule is deprecated and you should use ActivityScenario or ActivityScenarioRule(which contains the first).

Prerequisites. Create decorView variable and assign it before tests;

    @Rule
    public ActivityScenarioRule<FeedActivity> activityScenarioRule = new ActivityScenarioRule<>(FeedActivity.class);

    private View decorView;

    @Before
    public void setUp() {
        activityScenarioRule.getScenario().onActivity(new ActivityScenario.ActivityAction<FeedActivity>() {
            @Override
            public void perform(FeedActivityactivity) {
                decorView = activity.getWindow().getDecorView();
            }
        });
}

Test itself

@Test
public void given_when_thenShouldShowToast() {
    String expectedWarning = getApplicationContext().getString(R.string.error_empty_list);
    onView(withId(R.id.button))
            .perform(click());

    onView(withText(expectedWarning))
            .inRoot(withDecorView(not(decorView)))// Here we use decorView
            .check(matches(isDisplayed()));
}

getApplicationContext() can be taken from androidx.test.core.app.ApplicationProvider.getApplicationContext;