/** * Copyright (c) 2016-present, RxJava Contributors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.reactivex.observable; import static org.junit.Assert.assertEquals; import java.util.*; import org.junit.Test; import io.reactivex.Observable; import io.reactivex.ObservableTransformer; import io.reactivex.functions.*; import io.reactivex.observables.GroupedObservable; import io.reactivex.observers.TestObserver; /** * Test super/extends of generics. * * See https://github.com/Netflix/RxJava/pull/331 */ public class ObservableCovarianceTest { /** * This won't compile if super/extends isn't done correctly on generics. */ @Test public void testCovarianceOfFrom() { Observable.<Movie> just(new HorrorMovie()); Observable.<Movie> fromIterable(new ArrayList<HorrorMovie>()); // Observable.<HorrorMovie>from(new Movie()); // may not compile } @Test public void testSortedList() { Comparator<Media> SORT_FUNCTION = new Comparator<Media>() { @Override public int compare(Media t1, Media t2) { return 1; } }; // this one would work without the covariance generics Observable<Media> o = Observable.just(new Movie(), new TVSeason(), new Album()); o.toSortedList(SORT_FUNCTION); // this one would NOT work without the covariance generics Observable<Movie> o2 = Observable.just(new Movie(), new ActionMovie(), new HorrorMovie()); o2.toSortedList(SORT_FUNCTION); } @Test public void testGroupByCompose() { Observable<Movie> movies = Observable.just(new HorrorMovie(), new ActionMovie(), new Movie()); TestObserver<String> ts = new TestObserver<String>(); movies .groupBy(new Function<Movie, Object>() { @Override public Object apply(Movie v) { return v.getClass(); } }) .doOnNext(new Consumer<GroupedObservable<Object, Movie>>() { @Override public void accept(GroupedObservable<Object, Movie> g) { System.out.println(g.getKey()); } }) .flatMap(new Function<GroupedObservable<Object, Movie>, Observable<String>>() { @Override public Observable<String> apply(GroupedObservable<Object, Movie> g) { return g .doOnNext(new Consumer<Movie>() { @Override public void accept(Movie pv) { System.out.println(pv); } }) .compose(new ObservableTransformer<Movie, Movie>() { @Override public Observable<Movie> apply(Observable<Movie> m) { return m.concatWith(Observable.just(new ActionMovie())); } } ) .map(new Function<Movie, String>() { @Override public String apply(Movie v) { return v.toString(); } }); } }) .subscribe(ts); ts.assertTerminated(); ts.assertNoErrors(); // System.out.println(ts.getOnNextEvents()); assertEquals(6, ts.valueCount()); } @SuppressWarnings("unused") @Test public void testCovarianceOfCompose() { Observable<HorrorMovie> movie = Observable.just(new HorrorMovie()); Observable<Movie> movie2 = movie.compose(new ObservableTransformer<HorrorMovie, Movie>() { @Override public Observable<Movie> apply(Observable<HorrorMovie> t) { return Observable.just(new Movie()); } }); } @SuppressWarnings("unused") @Test public void testCovarianceOfCompose2() { Observable<Movie> movie = Observable.<Movie> just(new HorrorMovie()); Observable<HorrorMovie> movie2 = movie.compose(new ObservableTransformer<Movie, HorrorMovie>() { @Override public Observable<HorrorMovie> apply(Observable<Movie> t) { return Observable.just(new HorrorMovie()); } }); } @SuppressWarnings("unused") @Test public void testCovarianceOfCompose3() { Observable<Movie> movie = Observable.<Movie>just(new HorrorMovie()); Observable<HorrorMovie> movie2 = movie.compose(new ObservableTransformer<Movie, HorrorMovie>() { @Override public Observable<HorrorMovie> apply(Observable<Movie> t) { return Observable.just(new HorrorMovie()).map(new Function<HorrorMovie, HorrorMovie>() { @Override public HorrorMovie apply(HorrorMovie v) { return v; } }); } } ); } @SuppressWarnings("unused") @Test public void testCovarianceOfCompose4() { Observable<HorrorMovie> movie = Observable.just(new HorrorMovie()); Observable<HorrorMovie> movie2 = movie.compose(new ObservableTransformer<HorrorMovie, HorrorMovie>() { @Override public Observable<HorrorMovie> apply(Observable<HorrorMovie> t1) { return t1.map(new Function<HorrorMovie, HorrorMovie>() { @Override public HorrorMovie apply(HorrorMovie v) { return v; } }); } }); } @Test public void testComposeWithDeltaLogic() { List<Movie> list1 = Arrays.asList(new Movie(), new HorrorMovie(), new ActionMovie()); List<Movie> list2 = Arrays.asList(new ActionMovie(), new Movie(), new HorrorMovie(), new ActionMovie()); Observable<List<Movie>> movies = Observable.just(list1, list2); movies.compose(deltaTransformer); } static Function<List<List<Movie>>, Observable<Movie>> calculateDelta = new Function<List<List<Movie>>, Observable<Movie>>() { @Override public Observable<Movie> apply(List<List<Movie>> listOfLists) { if (listOfLists.size() == 1) { return Observable.fromIterable(listOfLists.get(0)); } else { // diff the two List<Movie> newList = listOfLists.get(1); List<Movie> oldList = new ArrayList<Movie>(listOfLists.get(0)); Set<Movie> delta = new LinkedHashSet<Movie>(); delta.addAll(newList); // remove all that match in old delta.removeAll(oldList); // filter oldList to those that aren't in the newList oldList.removeAll(newList); // for all left in the oldList we'll create DROP events for (@SuppressWarnings("unused") Movie old : oldList) { delta.add(new Movie()); } return Observable.fromIterable(delta); } } }; static ObservableTransformer<List<Movie>, Movie> deltaTransformer = new ObservableTransformer<List<Movie>, Movie>() { @Override public Observable<Movie> apply(Observable<List<Movie>> movieList) { return movieList .startWith(new ArrayList<Movie>()) .buffer(2, 1) .skip(1) .flatMap(calculateDelta); } }; /* * Most tests are moved into their applicable classes such as [Operator]Tests.java */ static class Media { } static class Movie extends Media { } static class HorrorMovie extends Movie { } static class ActionMovie extends Movie { } static class Album extends Media { } static class TVSeason extends Media { } static class Rating { } static class CoolRating extends Rating { } static class Result { } static class ExtendedResult extends Result { } }