android-espresso-sorted-list-is-sorted-alphabetically

TeamsActivityTest.java

private static Matcher<View> isSortedAlphabetically() {  
    return new TypeSafeMatcher<View>() {

        private final List<String> teamNames = new ArrayList<>();

        @Override
        protected boolean matchesSafely(View item) {
            RecyclerView recyclerView = (RecyclerView) item;
            TeamsAdapter teamsAdapter = (TeamsAdapter) recyclerView.getAdapter();
            teamNames.clear();
            teamNames.addAll(extractTeamNames(teamsAdapter.getTeams()));
            return Ordering.natural().isOrdered(teamNames);
        }

        private List<String> extractTeamNames(List<Team> teams) {
            List<String> teamNames = new ArrayList<>();
            for (Team team : teams) {
                teamNames.add(team.name);
            }
            return teamNames;
        }

        @Override
        public void describeTo(Description description) {
            description.appendText("has items sorted alphabetically: " + teamNames);
        }
    };
}