ToastMatcher.java

package br.com.uilquemessias.utils;

import android.os.IBinder;
import android.support.test.espresso.Root;
import android.view.WindowManager;

import org.androidannotations.annotations.res.StringRes;
import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

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

public final class CustomMatcher {

    private CustomMatcher() {
    }

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

    public static void isToastMessageDisplayed(String text) {
        onView(withText(text)).inRoot(isToast()).check(matches(isDisplayed()));
    }

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

    public static 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();

                // 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.
                if (windowToken == appToken)
                    return true;
            }

            return false;
        }
    }
}