/*
 * 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.lucene.backward_index;

import java.nio.file.Path;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.SegmentInfos;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.apache.lucene.tests.util.TestUtil;
import org.apache.lucene.util.Version;

public class TestMigrateUpgradeExample extends LuceneTestCase {

  public void testForceMergeUpgradesSingleSegmentIndex() throws Exception {
    Path indexPath = createTempDir();
    TestUtil.unzip(getDataInputStream("moreterms.9.0.0.zip"), indexPath);
    try (Directory dir = FSDirectory.open(indexPath)) {
      IndexWriterConfig config = new IndexWriterConfig();
      try (IndexWriter writer = new IndexWriter(dir, config)) {
        writer.forceMerge(1);
      }
      // MIGRATE.md: forceMerge(1) "Rewrites all segments to latest format"; actual: the 9.0.0 segment is kept
      assertEquals(Version.LATEST, SegmentInfos.readLatestCommit(dir).info(0).info.getVersion());
    }
  }
}