// Matches a Hamcrest matcher
onView(withId(R.id.text)).check(matches(withText("Hello")));
onView(withId(R.id.btn)).check(matches(isDisplayed()));
onView(withId(R.id.btn)).check(matches(isEnabled()));
onView(withId(R.id.btn)).check(matches(isChecked()));
onView(withId(R.id.btn)).check(matches(not(isEnabled())));

// View does not exist
onView(withId(R.id.error_msg)).check(doesNotExist());

// Matches position
onView(withId(R.id.list_item)).check(isCompletelyDisplayed());