Checking toast message in android espresso

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.

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()));

The accepted answer is a good one but didn't work for me. So I searched a bit and found this blog article. This gave me an idea of how to do it and I updated the solution above.

First I implemented the ToastMatcher:

import android.os.IBinder;
import android.support.test.espresso.Root;
import android.view.WindowManager;
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;

public class ToastMatcher extends TypeSafeMatcher<Root> {

  @Override
  public void describeTo(Description description) {
    description.appendText("is toast");
  }

  @Override
  public boolean matchesSafely(Root root) {
    int type = root.getWindowLayoutParams().get().type;
    if (type == WindowManager.LayoutParams.TYPE_TOAST) {
        IBinder windowToken = root.getDecorView().getWindowToken();
        IBinder appToken = root.getDecorView().getApplicationWindowToken();
        if (windowToken == appToken) {
            // windowToken == appToken means this window isn't contained by any other windows.
            // if it was a window for an activity, it would have TYPE_BASE_APPLICATION.
            return true;
        }
    }
    return false;
  }

}

Then I implemented my check methods like this:

public void isToastMessageDisplayed(int textId) {
    onView(withText(textId)).inRoot(MobileViewMatchers.isToast()).check(matches(isDisplayed()));
}

MobileViewMatchers is a container for accessing the matchers. There I defined the static method isToast().

public static Matcher<Root> isToast() {
    return new ToastMatcher();
}

This works like a charm for me.

First make sure to import:

import static android.support.test.espresso.Espresso.onView;
import static android.support.test.espresso.matcher.ViewMatchers.withText;
import static android.support.test.espresso.matcher.RootMatchers.withDecorView;
import static android.support.test.espresso.assertion.ViewAssertions.matches;

Inside your class you probably have a rule like this:

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

Inside your test:

MyNameActivity activity = activityTestRule.getActivity();
onView(withText(R.string.toast_text)).
    inRoot(withDecorView(not(is(activity.getWindow().getDecorView())))).
    check(matches(isDisplayed()));

This worked for me, and it was pretty easy to use.

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;

First create a cutom Toast Matcher which we can use in our test cases -

public class ToastMatcher extends TypeSafeMatcher<Root> {
    
        @Override    public void describeTo(Description description) {
            description.appendText("is toast");
        }
    
        @Override    public boolean matchesSafely(Root root) {
            int type = root.getWindowLayoutParams().get().type;
            if ((type == WindowManager.LayoutParams.TYPE_TOAST)) {
                IBinder windowToken = root.getDecorView().getWindowToken();
                IBinder appToken = root.getDecorView().getApplicationWindowToken();
                if (windowToken == appToken) {
                  //means this window isn't contained by any other windows. 
                  return true;
                }
            }
            return false;
        }
}

1. Test if the Toast Message is Displayed

onView(withText(R.string.mssage)).inRoot(new ToastMatcher())
.check(matches(isDisplayed()));

2. Test if the Toast Message is not Displayed

onView(withText(R.string.mssage)).inRoot(new ToastMatcher())
.check(matches(not(isDisplayed())));

3. Test id the Toast contains specific Text Message

onView(withText(R.string.mssage)).inRoot(new ToastMatcher())
.check(matches(withText("Invalid Name"));

Thanks, Anuja

Note - this answer is from This POST.

Though the question has an accepted answer - which BTW does not work for me - I'd like to add my solution in Kotlin which I derived from Thomas R.'s answer:

package somepkg

import android.support.test.espresso.Espresso.onView
import android.support.test.espresso.Root
import android.support.test.espresso.matcher.ViewMatchers.withText
import android.view.WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
import android.view.WindowManager.LayoutParams.TYPE_TOAST
import org.hamcrest.Description
import org.hamcrest.Matcher
import org.hamcrest.TypeSafeMatcher

/**
 * This class allows to match Toast messages in tests with Espresso.
 *
 * Idea taken from: https://stackoverflow.com/a/33387980
 *
 * Usage in test class:
 *
 * import somepkg.ToastMatcher.Companion.onToast
 *
 * // To assert a toast does *not* pop up:
 * onToast("text").check(doesNotExist())
 * onToast(textId).check(doesNotExist())
 *
 * // To assert a toast does pop up:
 * onToast("text").check(matches(isDisplayed()))
 * onToast(textId).check(matches(isDisplayed()))
 */
class ToastMatcher(private val maxFailures: Int = DEFAULT_MAX_FAILURES) : TypeSafeMatcher<Root>() {

    /** Restrict number of false results from matchesSafely to avoid endless loop */
    private var failures = 0

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

    public override fun matchesSafely(root: Root): Boolean {
        val type = root.windowLayoutParams.get().type
        @Suppress("DEPRECATION") // TYPE_TOAST is deprecated in favor of TYPE_APPLICATION_OVERLAY
        if (type == TYPE_TOAST || type == TYPE_APPLICATION_OVERLAY) {
            val windowToken = root.decorView.windowToken
            val appToken = root.decorView.applicationWindowToken
            if (windowToken === appToken) {
                // windowToken == appToken means this window isn't contained by any other windows.
                // if it was a window for an activity, it would have TYPE_BASE_APPLICATION.
                return true
            }
        }
        // Method is called again if false is returned which is useful because a toast may take some time to pop up. But for
        // obvious reasons an infinite wait isn't of help. So false is only returned as often as maxFailures specifies.
        return (++failures >= maxFailures)
    }

    companion object {

        /** Default for maximum number of retries to wait for the toast to pop up */
        private const val DEFAULT_MAX_FAILURES = 5

        fun onToast(text: String, maxRetries: Int = DEFAULT_MAX_FAILURES) = onView(withText(text)).inRoot(isToast(maxRetries))!!

        fun onToast(textId: Int, maxRetries: Int = DEFAULT_MAX_FAILURES) = onView(withText(textId)).inRoot(isToast(maxRetries))!!

        fun isToast(maxRetries: Int = DEFAULT_MAX_FAILURES): Matcher<Root> {
            return ToastMatcher(maxRetries)
        }
    }

}

I hope this will be of help for later readers - the usage is described in the comment.

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()))

For kotlin, I had to use the apply extension function, and this worked for me.

1- declare your ToastMatcher class in the androidTest folder:

class ToastMatcher : TypeSafeMatcher<Root?>() {

override fun matchesSafely(item: Root?): Boolean {
        val type: Int? = item?.windowLayoutParams?.get()?.type
        if (type == WindowManager.LayoutParams.FIRST_APPLICATION_WINDOW) {
            val windowToken: IBinder = item.decorView.windowToken
            val appToken: IBinder = item.decorView.applicationWindowToken
            if (windowToken === appToken) { // means this window isn't contained by any other windows.
                return true
            }
        }
        return false
    }

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

2- Then you use like this to test that the toast message actually displays

onView(withText(R.string.invalid_phone_number))
        .inRoot(ToastMatcher().apply {
            matches(isDisplayed())
        });

Attribution to ToastMatcher class:

/**
 * Author: http://www.qaautomated.com/2016/01/how-to-test-toast-message-using-espresso.html
 */

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()));

I would like to suggest an alternative method, especially if you need to check that particular toast is NOT displayed

The problem here that

onView(viewMatcher)
    .inRoot(RootMatchers.isPlatformPopup())
    .check(matches(not(isDisplayed())))

or

onView(viewMatcher)
    .inRoot(RootMatchers.isPlatformPopup())
    .check(doesNotExist())

or any other custom inRoot checks are throwing NoMatchingRootException even before the code passes to check method

You may just catch the exception and complete the test but that's not a good option since throwing and catching NoMatchingRootException consumes a lot of time in a comparison with the default test case. Seems that Espresso is waiting for the Root for a while

For this case is suggest just to give up with espresso here and use UiAutomator for this assertion. The Espresso and UiAutomator frameworks could easily work together in one environment.

val device: UiDevice
   get() = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation())

fun assertPopupIsNotDisplayed() {
    device.waitForIdle()
    assertFalse(device.hasObject(By.text(yourText))))
}

fun assertPopupIsDisplayed() {
    device.waitForIdle()
    assertTrue(device.hasObject(By.text(yourText))))
}

Using ActivityScenarioRule and Java

Some imports for the code

import android.view.View;
import androidx.test.ext.junit.rules.ActivityScenarioRule;

import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;

import static androidx.test.espresso.Espresso.onView;
import static androidx.test.espresso.matcher.RootMatchers.withDecorView;
import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
import static androidx.test.espresso.matcher.ViewMatchers.withId;
import static androidx.test.espresso.matcher.ViewMatchers.withText;
import static org.hamcrest.Matchers.not;

1. Declare the rule

//Change YourActivity by the activity you are testing
@Rule
public ActivityScenarioRule<YourActivity> activityRule
        = new ActivityScenarioRule<>(YourActivity.class);

2. Initialize the decor view

    private View decorView;

    @Before
    public void loadDecorView() {
        activityRule.getScenario().onActivity(
                activity -> decorView = activity.getWindow().getDecorView()
        );
    }

3. Finally test it

    @Test
    public void testWithToasts() {


        //Arrange and act code

        //Modify toast_msg to your own string resource
        onView(withText(R.string.toast_msg)).
                inRoot(RootMatchers.withDecorView(not(decorView)))
                .check(matches(isDisplayed()));
    }

I'm pretty new to this, but I made a base class 'BaseTest' that has all of my actions (swiping, clicking, etc.) and verifications (checking text views for content, etc.).

protected fun verifyToastMessageWithText(text: String, activityTestRule: ActivityTestRule<*>) {
        onView(withText(text)).inRoot(withDecorView(not(activityTestRule.activity.window.decorView))).check(matches(isDisplayed()))
    }

protected fun verifyToastMessageWithStringResource(id: Int, activityTestRule: ActivityTestRule<*>) {
        onView(withText(id)).inRoot(withDecorView(not(activityTestRule.activity.window.decorView))).check(matches(isDisplayed()))
    }

> this works for me

onView(withId(R.id.inputField)).check(matches(withText("Lalala")));

The way Toasts are implemented makes it possible to detect a toast has been displayed. However there is no way to see if a Toast has been requested, thru a call to show()) or to block between the period of time between show() and when the toast has become visible. This is opens up unresolvable timing issues (that you can only address thru sleep & hope).

If you really really want to verify this, here's a not-so-pretty alternative using Mockito and a test spy:

public interface Toaster {
 public void showToast(Toast t);

 private static class RealToaster {
  @Override
  public void showToast(Toast t) {
    t.show();
  }

 public static Toaster makeToaster() {
   return new RealToaster();
 }
}

Then in your test

public void testMyThing() {
 Toaster spyToaster = Mockito.spy(Toaster.makeToaster());
 getActivity().setToaster(spyToaster);
 onView(withId(R.button)).perform(click());
 getInstrumentation().runOnMainSync(new Runnable() {
 @Override
  public void run() {
   // must do this on the main thread because the matcher will be interrogating a view...
   Mockito.verify(spyToaster).showToast(allOf(withDuration(Toast.LENGTH_SHORT), withView(withText("hello world"));
 });
}

// create a matcher that calls getDuration() on the toast object
Matcher<Toast> withDuration(int)
// create a matcher that calls getView() and applies the given view matcher
Matcher<Toast> withView(Matcher<View> viewMatcher)




another answer regarding this 




if(someToast == null)
    someToast = Toast.makeText(this, "sdfdsf", Toast.LENGTH_LONG);
boolean isShown = someToast.getView().isShown();