Espresso view visibility assertions

ExtraAssertions.java

public class ExtraAssertions {
	public static ViewAssertion isVisible() {
		return (view, noView) -> assertThat(view, new VisibilityMatcher(View.VISIBLE));
	}

	public static ViewAssertion isGone() {
		return (view, noView) -> assertThat(view, new VisibilityMatcher(View.GONE));
	}

	public static ViewAssertion isInvisible() {
		return (view, noView) -> assertThat(view, new VisibilityMatcher(View.INVISIBLE));
	}

	private static class VisibilityMatcher extends BaseMatcher<View> {

		private int visibility;

		public VisibilityMatcher(int visibility) {
			this.visibility = visibility;
		}

		@Override public void describeTo(Description description) {
			String visibilityName;
			if (visibility == View.GONE) visibilityName = "GONE";
			else if (visibility == View.VISIBLE) visibilityName = "VISIBLE";
			else visibilityName = "INVISIBLE";
			description.appendText("View visibility must has equals " + visibilityName);
		}

		@Override public boolean matches(Object o) {

			if (o == null) {
				if (visibility == View.GONE || visibility == View.INVISIBLE) return true;
				else if (visibility == View.VISIBLE) return false;
			}

			if (!(o instanceof View))
				throw new IllegalArgumentException("Object must be instance of View. Object is instance of " + o);
			return ((View) o).getVisibility() == visibility;
		}
	}
}