/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.beam.sdk.fn.stream;

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;

import org.apache.beam.vendor.grpc.v1.io.grpc.stub.ClientCallStreamObserver;
import org.apache.beam.vendor.grpc.v1.io.grpc.stub.ClientResponseObserver;
import org.apache.beam.vendor.grpc.v1.io.grpc.stub.StreamObserver;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link ForwardingClientResponseObserver}. */
@RunWith(JUnit4.class)
public class ForwardingClientResponseObserverTest {
  @Test
  public void testCallsAreForwardedAndOnReadyHandlerBound() {
    @SuppressWarnings("unchecked")
    StreamObserver<Object> delegateObserver = mock(StreamObserver.class);
    @SuppressWarnings("unchecked")
    ClientCallStreamObserver<Object> callStreamObserver = mock(ClientCallStreamObserver.class);
    Runnable onReadyHandler = () -> {};
    ClientResponseObserver<Object, Object> observer =
        new ForwardingClientResponseObserver<>(delegateObserver, onReadyHandler);
    observer.onNext("A");
    verify(delegateObserver).onNext("A");
    Throwable t = new RuntimeException();
    observer.onError(t);
    verify(delegateObserver).onError(t);
    observer.onCompleted();
    verify(delegateObserver).onCompleted();
    observer.beforeStart(callStreamObserver);
    verify(callStreamObserver).setOnReadyHandler(onReadyHandler);
    verifyNoMoreInteractions(delegateObserver, callStreamObserver);
  }
}
