src/test/java/io/reactivex/rxjava4/flowable/FlowableTests.java - 4.x - githubmirror/RxJava

src/test/java/io/reactivex/rxjava4/flowable/FlowableTests.java
972 строки31 KB
David Karnok
4.x: Streamable + takeUntil + groupBy + refactor + helpers (#8215)
05 июл 2026, 01:45
05 июл 2026, 01:45580b39c
/*
 * 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.rxjava4.flowable;

import static org.junit.jupiter.api.Assertions.*;
import static org.mockito.ArgumentMatchers.*;
import static org.mockito.Mockito.*;

import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.Flow.Subscriber;
import java.util.concurrent.atomic.*;

import org.junit.jupiter.api.*;
import org.mockito.InOrder;

import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.disposables.Disposable;
import io.reactivex.rxjava4.exceptions.*;
import io.reactivex.rxjava4.functions.Predicate;
import io.reactivex.rxjava4.internal.functions.Functions;
import io.reactivex.rxjava4.internal.subscriptions.BooleanSubscription;
import io.reactivex.rxjava4.plugins.RxJavaPlugins;
import io.reactivex.rxjava4.processors.*;
import io.reactivex.rxjava4.schedulers.*;
import io.reactivex.rxjava4.subscribers.*;
import io.reactivex.rxjava4.testsupport.*;

public class FlowableTests extends RxJavaTest {

    Subscriber<Number> w;

    SingleObserver<Number> wo;

    MaybeObserver<Number> wm;

    private static final Predicate<Integer> IS_EVEN = v -> v % 2 == 0;

    @BeforeEach
    public void before() {
        w = TestHelper.mockSubscriber();
        wo = TestHelper.mockSingleObserver();
        wm = TestHelper.mockMaybeObserver();
    }

    @Test
    public void fromArray() {
        String[] items = new String[] { "one", "two", "three" };
        assertEquals((Long)3L, Flowable.fromArray(items).count().blockingGet());
        assertEquals("two", Flowable.fromArray(items).skip(1).take(1).blockingSingle());
        assertEquals("three", Flowable.fromArray(items).takeLast(1).blockingSingle());
    }

    @Test
    public void fromIterable() {
        ArrayList<String> items = new ArrayList<>();
        items.add("one");
        items.add("two");
        items.add("three");

        assertEquals((Long)3L, Flowable.fromIterable(items).count().blockingGet());
        assertEquals("two", Flowable.fromIterable(items).skip(1).take(1).blockingSingle());
        assertEquals("three", Flowable.fromIterable(items).takeLast(1).blockingSingle());
    }

    @Test
    public void fromArityArgs3() {
        Flowable<String> items = Flowable.just("one", "two", "three");

        assertEquals((Long)3L, items.count().blockingGet());
        assertEquals("two", items.skip(1).take(1).blockingSingle());
        assertEquals("three", items.takeLast(1).blockingSingle());
    }

    @Test
    public void fromArityArgs1() {
        Flowable<String> items = Flowable.just("one");

        assertEquals((Long)1L, items.count().blockingGet());
        assertEquals("one", items.takeLast(1).blockingSingle());
    }

    @Test
    public void create() {

        Flowable<String> flowable = Flowable.just("one", "two", "three");

        Subscriber<String> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, times(1)).onNext("one");
        verify(subscriber, times(1)).onNext("two");
        verify(subscriber, times(1)).onNext("three");
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void countAFewItemsFlowable() {
        Flowable<String> flowable = Flowable.just("a", "b", "c", "d");

        flowable.count().toFlowable().subscribe(w);

        // we should be called only once
        verify(w).onNext(4L);
        verify(w, never()).onError(any(Throwable.class));
        verify(w, times(1)).onComplete();
    }

    @Test
    public void countZeroItemsFlowable() {
        Flowable<String> flowable = Flowable.empty();
        flowable.count().toFlowable().subscribe(w);
        // we should be called only once
        verify(w).onNext(0L);
        verify(w, never()).onError(any(Throwable.class));
        verify(w, times(1)).onComplete();
    }

    @Test
    public void countErrorFlowable() {
        Flowable<String> f = Flowable.error(RuntimeException::new);

        f.count().toFlowable().subscribe(w);
        verify(w, never()).onNext(anyInt());
        verify(w, never()).onComplete();
        verify(w, times(1)).onError(any(RuntimeException.class));
    }

    @Test
    public void countAFewItems() {
        Flowable<String> flowable = Flowable.just("a", "b", "c", "d");

        flowable.count().subscribe(wo);

        // we should be called only once
        verify(wo).onSuccess(4L);
        verify(wo, never()).onError(any(Throwable.class));
    }

    @Test
    public void countZeroItems() {
        Flowable<String> flowable = Flowable.empty();
        flowable.count().subscribe(wo);
        // we should be called only once
        verify(wo).onSuccess(0L);
        verify(wo, never()).onError(any(Throwable.class));
    }

    @Test
    public void countError() {
        Flowable<String> f = Flowable.error(RuntimeException::new);

        f.count().subscribe(wo);
        verify(wo, never()).onSuccess(anyInt());
        verify(wo, times(1)).onError(any(RuntimeException.class));
    }

    @Test
    public void takeFirstWithPredicateOfSome() {
        Flowable<Integer> flowable = Flowable.just(1, 3, 5, 4, 6, 3);
        flowable.filter(IS_EVEN).take(1).subscribe(w);
        verify(w, times(1)).onNext(anyInt());
        verify(w).onNext(4);
        verify(w, times(1)).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void takeFirstWithPredicateOfNoneMatchingThePredicate() {
        Flowable<Integer> flowable = Flowable.just(1, 3, 5, 7, 9, 7, 5, 3, 1);
        flowable.filter(IS_EVEN).take(1).subscribe(w);
        verify(w, never()).onNext(anyInt());
        verify(w, times(1)).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void takeFirstOfSome() {
        Flowable<Integer> flowable = Flowable.just(1, 2, 3);
        flowable.take(1).subscribe(w);
        verify(w, times(1)).onNext(anyInt());
        verify(w).onNext(1);
        verify(w, times(1)).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void takeFirstOfNone() {
        Flowable<Integer> flowable = Flowable.empty();
        flowable.take(1).subscribe(w);
        verify(w, never()).onNext(anyInt());
        verify(w, times(1)).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void firstOfNoneFlowable() {
        Flowable<Integer> flowable = Flowable.empty();
        flowable.firstElement().toFlowable().subscribe(w);
        verify(w, never()).onNext(anyInt());
        verify(w).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void firstWithPredicateOfNoneMatchingThePredicateFlowable() {
        Flowable<Integer> flowable = Flowable.just(1, 3, 5, 7, 9, 7, 5, 3, 1);
        flowable.filter(IS_EVEN).firstElement().toFlowable().subscribe(w);
        verify(w, never()).onNext(anyInt());
        verify(w).onComplete();
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void firstOfNone() {
        Flowable<Integer> flowable = Flowable.empty();
        flowable.firstElement().subscribe(wm);
        verify(wm, never()).onSuccess(anyInt());
        verify(wm).onComplete();
        verify(wm, never()).onError(isA(NoSuchElementException.class));
    }

    @Test
    public void firstWithPredicateOfNoneMatchingThePredicate() {
        Flowable<Integer> flowable = Flowable.just(1, 3, 5, 7, 9, 7, 5, 3, 1);
        flowable.filter(IS_EVEN).firstElement().subscribe(wm);
        verify(wm, never()).onSuccess(anyInt());
        verify(wm, times(1)).onComplete();
        verify(wm, never()).onError(isA(NoSuchElementException.class));
    }

    @Test
    public void reduce() {
        Flowable<Integer> flowable = Flowable.just(1, 2, 3, 4);
        flowable.reduce(Integer::sum)
        .toFlowable()
        .subscribe(w);
        // we should be called only once
        verify(w, times(1)).onNext(anyInt());
        verify(w).onNext(10);
    }

    @Test
    public void reduceWithEmptyObservable() {
        Flowable<Integer> flowable = Flowable.range(1, 0);
        flowable.reduce(Integer::sum)
        .toFlowable()
        .test()
        .assertResult();
    }

    /**
     * A reduce on an empty Observable and a seed should just pass the seed through.
     *
     * This is confirmed at https://github.com/ReactiveX/RxJava/issues/423#issuecomment-27642456
     */
    @Test
    public void reduceWithEmptyObservableAndSeed() {
        Flowable<Integer> flowable = Flowable.range(1, 0);
        int value = flowable.reduce(1, Integer::sum)
        .blockingGet();

        assertEquals(1, value);
    }

    @Test
    public void reduceWithInitialValue() {
        Flowable<Integer> flowable = Flowable.just(1, 2, 3, 4);
        flowable.reduce(50, Integer::sum)
        .subscribe(wo);
        // we should be called only once
        verify(wo, times(1)).onSuccess(anyInt());
        verify(wo).onSuccess(60);
    }

    @Test
    public void materializeDematerializeChaining() {
        Flowable<Integer> obs = Flowable.just(1);
        Flowable<Integer> chained = obs.materialize()
                .dematerialize(Functions.<Notification<Integer>>identity());

        Subscriber<Integer> subscriber = TestHelper.mockSubscriber();

        chained.subscribe(subscriber);

        verify(subscriber, times(1)).onNext(1);
        verify(subscriber, times(1)).onComplete();
        verify(subscriber, times(0)).onError(any(Throwable.class));
    }

    /**
     * The error from the user provided Observer is not handled by the subscribe method try/catch.
     *
     * It is handled by the AtomicObserver that wraps the provided Observer.
     *
     * Result: Passes (if AtomicObserver functionality exists)
     * @throws InterruptedException if the test is interrupted
     */
    @Test
    public void customObservableWithErrorInObserverAsynchronous() throws InterruptedException {
        final CountDownLatch latch = new CountDownLatch(1);
        final AtomicInteger count = new AtomicInteger();
        final AtomicReference<Throwable> error = new AtomicReference<>();

        // FIXME custom built???
        Flowable.just("1", "2", "three", "4")
        .subscribeOn(Schedulers.newThread())
        .safeSubscribe(new DefaultSubscriber<>() /* NFI */ {
            @Override
            public void onComplete() {
                System.out.println("completed");
                latch.countDown();
            }

            @Override
            public void onError(Throwable e) {
                error.set(e);
                System.out.println("error");
                e.printStackTrace();
                latch.countDown();
            }

            @Override
            public void onNext(String v) {
                int num = Integer.parseInt(v);
                System.out.println(num);
                // doSomething(num);
                count.incrementAndGet();
            }

        });

        // wait for async sequence to complete
        latch.await();

        assertEquals(2, count.get());
        assertNotNull(error.get());
        if (!(error.get() instanceof NumberFormatException)) {
            fail("It should be a NumberFormatException");
        }
    }

    /**
     * The error from the user provided Observer is handled by the subscribe try/catch because this is synchronous.
     *
     * Result: Passes
     */
    @Test
    public void customObservableWithErrorInObserverSynchronous() {
        final AtomicInteger count = new AtomicInteger();
        final AtomicReference<Throwable> error = new AtomicReference<>();

        // FIXME custom built???
        Flowable.just("1", "2", "three", "4")
        .safeSubscribe(new DefaultSubscriber<>() /* NFI */ {

            @Override
            public void onComplete() {
                System.out.println("completed");
            }

            @Override
            public void onError(Throwable e) {
                error.set(e);
                System.out.println("error");
                e.printStackTrace();
            }

            @Override
            public void onNext(String v) {
                int num = Integer.parseInt(v);
                System.out.println(num);
                // doSomething(num);
                count.incrementAndGet();
            }

        });
        assertEquals(2, count.get());
        assertNotNull(error.get());
        if (!(error.get() instanceof NumberFormatException)) {
            fail("It should be a NumberFormatException");
        }
    }

    /**
     * The error from the user provided Observable is handled by the subscribe try/catch because this is synchronous.
     *
     * Result: Passes
     */
    @Test
    public void customObservableWithErrorInObservableSynchronous() {
        final AtomicInteger count = new AtomicInteger();
        final AtomicReference<Throwable> error = new AtomicReference<>();
        // FIXME custom built???
        Flowable.just("1", "2").concatWith(Flowable.<String>error(NumberFormatException::new))
        .subscribe(new DefaultSubscriber<>() /* NFI */ {

            @Override
            public void onComplete() {
                System.out.println("completed");
            }

            @Override
            public void onError(Throwable e) {
                error.set(e);
                System.out.println("error");
                e.printStackTrace();
            }

            @Override
            public void onNext(String v) {
                System.out.println(v);
                count.incrementAndGet();
            }

        });
        assertEquals(2, count.get());
        assertNotNull(error.get());
        if (!(error.get() instanceof NumberFormatException)) {
            fail("It should be a NumberFormatException");
        }
    }

    @Test
    public void publishLast() throws InterruptedException {
        final AtomicInteger count = new AtomicInteger();
        ConnectableFlowable<String> connectable = Flowable.<String>unsafeCreate(subscriber -> {
            subscriber.onSubscribe(new BooleanSubscription());
            count.incrementAndGet();
            new Thread(() -> {
                subscriber.onNext("first");
                subscriber.onNext("last");
                subscriber.onComplete();
            }).start();
        }).takeLast(1).publish();

        // subscribe once
        final CountDownLatch latch = new CountDownLatch(1);
        connectable.subscribe(value -> {
            assertEquals("last", value);
            latch.countDown();
        });

        // subscribe twice
        connectable.subscribe();

        Disposable subscription = connectable.connect();
        assertTrue(latch.await(1000, TimeUnit.MILLISECONDS));
        assertEquals(1, count.get());
        subscription.dispose();
    }

    @Test
    public void replay() throws InterruptedException {
        final AtomicInteger counter = new AtomicInteger();
        ConnectableFlowable<String> f = Flowable.<String>unsafeCreate(subscriber -> {
                subscriber.onSubscribe(new BooleanSubscription());
                new Thread(() -> {
                    counter.incrementAndGet();
                    subscriber.onNext("one");
                    subscriber.onComplete();
                }).start();
        }).replay();

        // we connect immediately and it will emit the value
        Disposable connection = f.connect();
        try {

            // we then expect the following 2 subscriptions to get that same value
            final CountDownLatch latch = new CountDownLatch(2);

            // subscribe once
            f.subscribe(v -> {
                assertEquals("one", v);
                latch.countDown();
            });

            // subscribe again
            f.subscribe(v -> {
                assertEquals("one", v);
                latch.countDown();
            });

            if (!latch.await(1000, TimeUnit.MILLISECONDS)) {
                fail("subscriptions did not receive values");
            }
            assertEquals(1, counter.get());
        } finally {
            connection.dispose();
        }
    }

    @Test
    public void cache() throws InterruptedException {
        final AtomicInteger counter = new AtomicInteger();
        Flowable<String> f = Flowable.<String>unsafeCreate(subscriber -> {
                subscriber.onSubscribe(new BooleanSubscription());
                new Thread(() -> {
                    counter.incrementAndGet();
                    subscriber.onNext("one");
                    subscriber.onComplete();
                }).start();
        }).cache();

        // we then expect the following 2 subscriptions to get that same value
        final CountDownLatch latch = new CountDownLatch(2);

        // subscribe once
        f.subscribe(v -> {
            assertEquals("one", v);
            latch.countDown();
        });

        // subscribe again
        f.subscribe(v -> {
            assertEquals("one", v);
            latch.countDown();
        });

        if (!latch.await(1000, TimeUnit.MILLISECONDS)) {
            fail("subscriptions did not receive values");
        }
        assertEquals(1, counter.get());
    }

    @Test
    public void cacheWithCapacity() throws InterruptedException {
        final AtomicInteger counter = new AtomicInteger();
        Flowable<String> f = Flowable.<String>unsafeCreate(subscriber -> {
            subscriber.onSubscribe(new BooleanSubscription());
            new Thread(() -> {
                counter.incrementAndGet();
                subscriber.onNext("one");
                subscriber.onComplete();
            }).start();
        }).cacheWithInitialCapacity(1);

        // we then expect the following 2 subscriptions to get that same value
        final CountDownLatch latch = new CountDownLatch(2);

        // subscribe once
        f.subscribe(v -> {
            assertEquals("one", v);
            latch.countDown();
        });

        // subscribe again
        f.subscribe(v -> {
            assertEquals("one", v);
            latch.countDown();
        });

        if (!latch.await(1000, TimeUnit.MILLISECONDS)) {
            fail("subscriptions did not receive values");
        }
        assertEquals(1, counter.get());
    }

    @Test
    public void takeWithErrorInObserver() {
        final AtomicInteger count = new AtomicInteger();
        final AtomicReference<Throwable> error = new AtomicReference<>();
        Flowable.just("1", "2", "three", "4").take(3)
        .safeSubscribe(new DefaultSubscriber<>() /* NFI */ {

            @Override
            public void onComplete() {
                System.out.println("completed");
            }

            @Override
            public void onError(Throwable e) {
                error.set(e);
                System.out.println("error");
                e.printStackTrace();
            }

            @Override
            public void onNext(String v) {
                int num = Integer.parseInt(v);
                System.out.println(num);
                // doSomething(num);
                count.incrementAndGet();
            }

        });
        assertEquals(2, count.get());
        assertNotNull(error.get());
        if (!(error.get() instanceof NumberFormatException)) {
            fail("It should be a NumberFormatException");
        }
    }

    @Test
    public void ofType() {
        Flowable<String> flowable = Flowable.just(1, "abc", false, 2L).ofType(String.class);

        Subscriber<Object> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, never()).onNext(1);
        verify(subscriber, times(1)).onNext("abc");
        verify(subscriber, never()).onNext(false);
        verify(subscriber, never()).onNext(2L);
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void ofTypeWithPolymorphism() {
        ArrayList<Integer> l1 = new ArrayList<>();
        l1.add(1);
        LinkedList<Integer> l2 = new LinkedList<>();
        l2.add(2);

        @SuppressWarnings("rawtypes")
        Flowable<List> flowable = Flowable.<Object> just(l1, l2, "123").ofType(List.class);

        Subscriber<Object> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, times(1)).onNext(l1);
        verify(subscriber, times(1)).onNext(l2);
        verify(subscriber, never()).onNext("123");
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void containsFlowable() {
        Flowable<Boolean> flowable = Flowable.just("a", "b", "c").contains("b").toFlowable();

        FlowableSubscriber<Boolean> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, times(1)).onNext(true);
        verify(subscriber, never()).onNext(false);
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void containsWithInexistenceFlowable() {
        Flowable<Boolean> flowable = Flowable.just("a", "b").contains("c").toFlowable();

        Subscriber<Object> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, times(1)).onNext(false);
        verify(subscriber, never()).onNext(true);
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void containsWithEmptyObservableFlowable() {
        Flowable<Boolean> flowable = Flowable.<String> empty().contains("a").toFlowable();

        FlowableSubscriber<Object> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, times(1)).onNext(false);
        verify(subscriber, never()).onNext(true);
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void contains() {
        Single<Boolean> single = Flowable.just("a", "b", "c").contains("b"); // FIXME nulls not allowed, changed to "c"

        SingleObserver<Boolean> observer = TestHelper.mockSingleObserver();

        single.subscribe(observer);

        verify(observer, times(1)).onSuccess(true);
        verify(observer, never()).onSuccess(false);
        verify(observer, never()).onError(
                any(Throwable.class));
    }

    @Test
    public void containsWithInexistence() {
        Single<Boolean> single = Flowable.just("a", "b").contains("c"); // FIXME null values are not allowed, removed

        SingleObserver<Boolean> observer = TestHelper.mockSingleObserver();

        single.subscribe(observer);

        verify(observer, times(1)).onSuccess(false);
        verify(observer, never()).onSuccess(true);
        verify(observer, never()).onError(
                any(Throwable.class));
    }

    @Test
    public void containsWithEmptyObservable() {
        Single<Boolean> single = Flowable.<String> empty().contains("a");

        SingleObserver<Boolean> observer = TestHelper.mockSingleObserver();

        single.subscribe(observer);

        verify(observer, times(1)).onSuccess(false);
        verify(observer, never()).onSuccess(true);
        verify(observer, never()).onError(
                any(Throwable.class));
    }

    @Test
    public void ignoreElementsFlowable() {
        Flowable<Integer> flowable = Flowable.just(1, 2, 3).ignoreElements().toFlowable();

        Subscriber<Object> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        verify(subscriber, never()).onNext(any(Integer.class));
        verify(subscriber, never()).onError(any(Throwable.class));
        verify(subscriber, times(1)).onComplete();
    }

    @Test
    public void ignoreElements() {
        Completable completable = Flowable.just(1, 2, 3).ignoreElements();

        CompletableObserver observer = TestHelper.mockCompletableObserver();

        completable.subscribe(observer);

        verify(observer, never()).onError(any(Throwable.class));
        verify(observer, times(1)).onComplete();
    }

    @Test
    public void justWithScheduler() {
        TestScheduler scheduler = new TestScheduler();
        Flowable<Integer> flowable = Flowable.fromArray(1, 2).subscribeOn(scheduler);

        Subscriber<Integer> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        scheduler.advanceTimeBy(1, TimeUnit.MILLISECONDS);

        InOrder inOrder = inOrder(subscriber);
        inOrder.verify(subscriber, times(1)).onNext(1);
        inOrder.verify(subscriber, times(1)).onNext(2);
        inOrder.verify(subscriber, times(1)).onComplete();
        inOrder.verifyNoMoreInteractions();
    }

    @Test
    public void startWithWithScheduler() {
        TestScheduler scheduler = new TestScheduler();
        Flowable<Integer> flowable = Flowable.just(3, 4).startWithIterable(Arrays.asList(1, 2)).subscribeOn(scheduler);

        Subscriber<Integer> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        scheduler.advanceTimeBy(1, TimeUnit.MILLISECONDS);

        InOrder inOrder = inOrder(subscriber);
        inOrder.verify(subscriber, times(1)).onNext(1);
        inOrder.verify(subscriber, times(1)).onNext(2);
        inOrder.verify(subscriber, times(1)).onNext(3);
        inOrder.verify(subscriber, times(1)).onNext(4);
        inOrder.verify(subscriber, times(1)).onComplete();
        inOrder.verifyNoMoreInteractions();
    }

    @Test
    public void rangeWithScheduler() {
        TestScheduler scheduler = new TestScheduler();
        Flowable<Integer> flowable = Flowable.range(3, 4).subscribeOn(scheduler);

        Subscriber<Integer> subscriber = TestHelper.mockSubscriber();

        flowable.subscribe(subscriber);

        scheduler.advanceTimeBy(1, TimeUnit.MILLISECONDS);

        InOrder inOrder = inOrder(subscriber);
        inOrder.verify(subscriber, times(1)).onNext(3);
        inOrder.verify(subscriber, times(1)).onNext(4);
        inOrder.verify(subscriber, times(1)).onNext(5);
        inOrder.verify(subscriber, times(1)).onNext(6);
        inOrder.verify(subscriber, times(1)).onComplete();
        inOrder.verifyNoMoreInteractions();
    }

    @Test
    public void mergeWith() {
        TestSubscriber<Integer> ts = new TestSubscriber<>();
        Flowable.just(1).mergeWith(Flowable.just(2)).subscribe(ts);
        ts.assertValues(1, 2);
    }

    @Test
    public void concatWith() {
        TestSubscriber<Integer> ts = new TestSubscriber<>();
        Flowable.just(1).concatWith(Flowable.just(2)).subscribe(ts);
        ts.assertValues(1, 2);
    }

    @Test
    public void ambWith() {
        TestSubscriber<Integer> ts = new TestSubscriber<>();
        Flowable.just(1).ambWith(Flowable.just(2)).subscribe(ts);
        ts.assertValue(1);
    }

    @Test
    public void takeWhileToList() {
        final int expectedCount = 3;
        final AtomicInteger count = new AtomicInteger();
        for (int i = 0; i < expectedCount; i++) {
            Flowable
                    .just(Boolean.TRUE, Boolean.FALSE)
                    .takeWhile(v -> v)
                    .toList()
                    .doOnSuccess(_ -> count.incrementAndGet())
                    .subscribe();
        }
        assertEquals(expectedCount, count.get());
    }

    @Test
    public void compose() {
        TestSubscriberEx<String> ts = new TestSubscriberEx<>();
        Flowable.just(1, 2, 3).compose(t1 -> t1.map(String::valueOf))
        .subscribe(ts);
        ts.assertTerminated();
        ts.assertNoErrors();
        ts.assertValues("1", "2", "3");
    }

    @Test
    public void errorThrownIssue1685() {
        List<Throwable> errors = TestHelper.trackPluginErrors();
        try {
            FlowableProcessor<Object> processor = ReplayProcessor.create();

            Flowable.error(new RuntimeException("oops"))
                .materialize()
                .delay(1, TimeUnit.SECONDS)
                .dematerialize(Functions.<Notification<Object>>identity())
                .subscribe(processor);

            processor.subscribe();
            processor.materialize().blockingFirst();

            System.out.println("Done");

            TestHelper.assertError(errors, 0, OnErrorNotImplementedException.class);
        } finally {
            RxJavaPlugins.reset();
        }
    }

    @Test
    public void emptyIdentity() {
        assertEquals(Flowable.empty(), Flowable.empty());
    }

    @Test
    public void emptyIsEmpty() {
        Flowable.<Integer>empty().subscribe(w);

        verify(w).onComplete();
        verify(w, never()).onNext(any(Integer.class));
        verify(w, never()).onError(any(Throwable.class));
    }

    @Test
    public void extend() {
        final TestSubscriber<Object> subscriber = new TestSubscriber<>();
        final Object value = new Object();
        Object returned = Flowable.just(value).to(onSubscribe -> {
                onSubscribe.subscribe(subscriber);
                subscriber.assertNoErrors();
                subscriber.assertComplete();
                subscriber.assertValue(value);
                return subscriber.values().getFirst();
            });
        assertSame(returned, value);
    }

    @Test
    public void asExtend() {
        final TestSubscriber<Object> subscriber = new TestSubscriber<>();
        final Object value = new Object();
        Object returned = Flowable.just(value).to(onSubscribe -> {
                onSubscribe.subscribe(subscriber);
                subscriber.assertNoErrors();
                subscriber.assertComplete();
                subscriber.assertValue(value);
                return subscriber.values().getFirst();
            });
        assertSame(returned, value);
    }

    @Test
    public void as() {
        Flowable.just(1).to(Flowable::toObservable)
        .test()
        .assertResult(1);
    }

    @Test
    public void toObservableEmpty() {
        Flowable.empty().toObservable().test().assertResult();
    }

    @Test
    public void toObservableJust() {
        Flowable.just(1).toObservable().test().assertResult(1);
    }

    @Test
    public void toObservableRange() {
        Flowable.range(1, 5).toObservable().test().assertResult(1, 2, 3, 4, 5);
    }

    @Test
    public void toObservableError() {
        Flowable.error(new TestException()).toObservable().test().assertFailure(TestException.class);
    }

    @Test
    public void zipIterableObject() {
        final List<Flowable<Integer>> flowables = Arrays.asList(Flowable.just(1, 2, 3), Flowable.just(1, 2, 3));
        Flowable.zip(flowables, o -> {
            int sum = 0;
            for (Object i : o) {
                sum += (Integer) i;
            }
            return sum;
        }).test().assertResult(2, 4, 6);
    }

    @Test
    public void combineLatestObject() {
        final List<Flowable<Integer>> flowables = Arrays.asList(Flowable.just(1, 2, 3), Flowable.just(1, 2, 3));
        Flowable.combineLatest(flowables, o -> {
            int sum = 1;
            for (Object i : o) {
                sum *= (Integer) i;
            }
            return sum;
        }).test().assertResult(3, 6, 9);
    }
}