/*
 * 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.index;

import java.util.Comparator;
import org.apache.lucene.document.Document;
import org.apache.lucene.store.ByteBuffersDirectory;
import org.apache.lucene.store.Directory;
import org.apache.lucene.tests.util.LuceneTestCase;

public class TestNrtOpenLeafSorterFailureReleasesFiles extends LuceneTestCase {

  // Expected: after a failed NRT open, merge and commit delete _0/_1; actual: their files stay.
  public void testFailedNrtOpenDoesNotKeepFilesOfMergedAwaySegments() throws Exception {
    Comparator<LeafReader> leafSorter =
        (a, b) -> {
          throw new IllegalStateException("leaf sorter failed");
        };
    try (Directory dir = new ByteBuffersDirectory();
        IndexWriter w = new IndexWriter(dir, new IndexWriterConfig().setLeafSorter(leafSorter))) {
      w.addDocument(new Document());
      w.commit();
      w.addDocument(new Document());
      w.commit();
      expectThrows(IllegalStateException.class, () -> DirectoryReader.open(w));
      w.forceMerge(1);
      w.commit();
      for (String file : dir.listAll()) {
        assertFalse(
            "file of a merged-away segment was not deleted: " + file,
            file.startsWith("_0") || file.startsWith("_1"));
      }
    }
  }
}