/*
 * 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.internal.operators.flowable;

import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;

import org.junit.Test;
import static java.util.concurrent.Flow.*;

import io.reactivex.rxjava4.core.*;
import io.reactivex.rxjava4.testsupport.*;

public class FlowableDefaultIfEmptyTest extends RxJavaTest {

    @Test
    public void defaultIfEmpty() {
        Flowable<Integer> source = Flowable.just(1, 2, 3);
        Flowable<Integer> flowable = source.defaultIfEmpty(10);

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

        flowable.subscribe(subscriber);

        verify(subscriber, never()).onNext(10);
        verify(subscriber).onNext(1);
        verify(subscriber).onNext(2);
        verify(subscriber).onNext(3);
        verify(subscriber).onComplete();
        verify(subscriber, never()).onError(any(Throwable.class));
    }

    @Test
    public void defaultIfEmptyWithEmpty() {
        Flowable<Integer> source = Flowable.empty();
        Flowable<Integer> flowable = source.defaultIfEmpty(10);

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

        flowable.subscribe(subscriber);

        verify(subscriber).onNext(10);
        verify(subscriber).onComplete();
        verify(subscriber, never()).onError(any(Throwable.class));
    }

    @Test
    public void backpressureEmpty() {
        TestSubscriberEx<Integer> ts = new TestSubscriberEx<>(0L);
        Flowable.<Integer>empty().defaultIfEmpty(1).subscribe(ts);
        ts.assertNoValues();
        ts.assertNotTerminated();
        ts.request(1);
        ts.assertValue(1);
        ts.assertNoErrors();
        ts.assertComplete();
    }

    @Test
    public void backpressureNonEmpty() {
        TestSubscriberEx<Integer> ts = new TestSubscriberEx<>(0L);
        Flowable.just(1, 2, 3).defaultIfEmpty(1).subscribe(ts);
        ts.assertNoValues();
        ts.assertNotTerminated();
        ts.request(2);
        ts.assertValues(1, 2);
        ts.request(1);
        ts.assertValues(1, 2, 3);
        ts.assertNoErrors();
        ts.assertComplete();
    }
}
