/*
 * 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.search.similarities;

import org.apache.lucene.search.FieldStats;
import org.apache.lucene.search.TermStats;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.apache.lucene.util.BytesRef;

public class TestDistributionLLNegativeZero extends LuceneTestCase {

  public void testZeroScoreIsPositiveZero() {
    Similarity.SimScorer scorer =
        new IBSimilarity(new DistributionLL(), new LambdaDF(), new NormalizationH1(0f))
            .scorer(
                1f,
                new FieldStats("f", 100, 100, 1000, 500),
                new TermStats(new BytesRef("t"), 10, 20));
    // c = 0 gives tfn = 0, so LL computes -log(1): expected +0.0 (as DistributionSPL), actual -0.0
    assertEquals(Float.valueOf(0f), Float.valueOf(scorer.score(1f, 1L)));
  }
}