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 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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
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package org.elasticsearch.discovery.single;

import org.apache.lucene.util.IOUtils;
import org.elasticsearch.Version;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateTaskListener;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.cluster.service.ClusterApplier;
import org.elasticsearch.cluster.service.MasterService;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.test.transport.MockTransportService;
import org.elasticsearch.threadpool.TestThreadPool;
import org.elasticsearch.threadpool.ThreadPool;

import java.io.Closeable;
import java.util.Stack;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Supplier;

import static org.elasticsearch.test.ClusterServiceUtils.createMasterService;
import static org.hamcrest.Matchers.equalTo;

public class SingleNodeDiscoveryTests extends ESTestCase {

    public void testInitialJoin() throws Exception {
        final Settings settings = Settings.EMPTY;
        final Version version = Version.CURRENT;
        final ThreadPool threadPool = new TestThreadPool(getClass().getName());
        final Stack<Closeable> stack = new Stack<>();
        try {
            final MockTransportService transportService =
                    MockTransportService.createNewService(settings, version, threadPool, null);
            stack.push(transportService);
            transportService.start();
            final DiscoveryNode node = transportService.getLocalNode();
            final MasterService masterService = createMasterService(threadPool, node);
            AtomicReference<ClusterState> clusterState = new AtomicReference<>();
            final SingleNodeDiscovery discovery =
                    new SingleNodeDiscovery(Settings.EMPTY, transportService,
                        masterService, new ClusterApplier() {
                            @Override
                            public void setInitialState(ClusterState initialState) {
                                clusterState.set(initialState);
                            }

                            @Override
                            public void onNewClusterState(String source, Supplier<ClusterState> clusterStateSupplier,
                                                          ClusterStateTaskListener listener) {
                                clusterState.set(clusterStateSupplier.get());
                                listener.clusterStateProcessed(source, clusterState.get(), clusterState.get());
                            }
                        });
            discovery.start();
            discovery.startInitialJoin();
            final DiscoveryNodes nodes = clusterState.get().nodes();
            assertThat(nodes.getSize(), equalTo(1));
            assertThat(nodes.getMasterNode().getId(), equalTo(node.getId()));
        } finally {
            while (!stack.isEmpty()) {
                IOUtils.closeWhileHandlingException(stack.pop());
            }
            terminate(threadPool);
        }
    }

}