Espresso & Brioche

CustomMatchers.java

/**
 * Custom Espresso matchers. Includes image drawable matching.
 */
public class CustomMatchers {
    public static Matcher<View> withBackground(final int resourceId) {
        return new TypeSafeMatcher<View>() {

            @Override
            public boolean matchesSafely(View view) {
                return sameBitmap(view.getContext(), view.getBackground(), resourceId);
            }

            @Override
            public void describeTo(Description description) {
                description.appendText("has background resource " + resourceId);
            }
        };
    }

    public static Matcher<View> withCompoundDrawable(final int resourceId) {
        return new BoundedMatcher<View, TextView>(TextView.class) {
            @Override
            public void describeTo(Description description) {
                description.appendText("has compound drawable resource " + resourceId);
            }

            @Override
            public boolean matchesSafely(TextView textView) {
                for (Drawable drawable : textView.getCompoundDrawables()) {
                    if (sameBitmap(textView.getContext(), drawable, resourceId)) {
                        return true;
                    }
                }
                return false;
            }
        };
    }

    public static Matcher<View> withImageDrawable(final int resourceId) {
        return new BoundedMatcher<View, ImageView>(ImageView.class) {
            @Override
            public void describeTo(Description description) {
                description.appendText("has image drawable resource " + resourceId);
            }

            @Override
            public boolean matchesSafely(ImageView imageView) {
                return sameBitmap(imageView.getContext(), imageView.getDrawable(), resourceId);
            }
        };
    }

    private static boolean sameBitmap(Context context, Drawable drawable, int resourceId) {
        Drawable otherDrawable = context.getResources().getDrawable(resourceId);
        if (drawable == null || otherDrawable == null) {
            return false;
        }
        if (drawable instanceof StateListDrawable && otherDrawable instanceof StateListDrawable) {
            drawable = drawable.getCurrent();
            otherDrawable = otherDrawable.getCurrent();
        }
        if (drawable instanceof BitmapDrawable) {
            final Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
            final Bitmap otherBitmap = ((BitmapDrawable) otherDrawable).getBitmap();
            return bitmap.sameAs(otherBitmap);
        } else if (drawable instanceof VectorDrawable) {
            final Bitmap bitmap = getBitmapFromVectorDrawable(drawable);
            final Bitmap otherBitmap = getBitmapFromVectorDrawable(otherDrawable);
            return bitmap.sameAs(otherBitmap);
        }
        return false;
    }

    private static Bitmap getBitmapFromVectorDrawable(@NonNull Drawable vectorDrawable) {
        final Bitmap bitmap = Bitmap.createBitmap(vectorDrawable.getIntrinsicWidth(),
                vectorDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        final Canvas canvas = new Canvas(bitmap);
        vectorDrawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        vectorDrawable.draw(canvas);
        return bitmap;
    }
}

EspressoTest.java

public class EspressoTest extends ActivityInstrumentationTestCase2<ShoppingActivity> {
  
    @Override
    public void setUp() throws Exception {
        super.setUp();
        setupInjections();
        setupPreferences();
        getActivity();
    }
    
    public void test_the_background_is_visible() throws Exception {
      onView(withImageDrawable(R.drawable.some_background)).check(matches(isDisplayed()));
    }
    
    public void test_the_card_has_a_specific_image() throws Exception {
      onView(withId(R.id.some_card)).check(matches(withImageDrawable(R.drawable.my_card));
    }
    
    public void test_this_textview_is_reused_so_we_have_to_manually_look_for_it() throws Exception {
      onView(allOf(withId(R.id.some_card), withParent(withId(R.id.textview_parent_left)))).check(matches(withCompoundDrawable(R.drawable.left_drawable));
    }
}