resolved header issue

Author: mridula-s109

x-pack/plugin/rank-rrf/src/test/java/org/elasticsearch/xpack/rank/linear/LinearRetrieverBuilderTests.java

@@ -1,10 +1,10 @@
 /*
  * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
  * or more contributor license agreements. Licensed under the Elastic License
- * 2.0 and the Server Side Public License, v 1; you may not use this file except
- * in compliance with, at your election, the Elastic License 2.0 or the Server
- * Side Public License, v 1.
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
  */
+
 package org.elasticsearch.xpack.rank.linear;
 
 import org.apache.lucene.search.ScoreDoc;

x-pack/plugin/rank-rrf/src/test/java/org/elasticsearch/xpack/rank/linear/LinearRetrieverBuilderTests.java.new

@@ -0,0 +1,114 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+package org.elasticsearch.xpack.rank.linear;
+
+/*
+ * 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.
+ */
+
+
+import org.apache.lucene.search.ScoreDoc;
+import org.elasticsearch.search.rank.RankDoc;
+import org.elasticsearch.search.retriever.CompoundRetrieverBuilder.RetrieverSource;
+import org.elasticsearch.search.retriever.TestRetrieverBuilder;
+import org.elasticsearch.test.ESTestCase;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.stream.Stream;
+
+public class LinearRetrieverBuilderTests extends ESTestCase {
+
+    public void testCombineInnerRetrieverResultsCalculatesWeightedSum() throws IOException {
+        List<RetrieverSource> sources = List.of(
+            new RetrieverSource(new TestRetrieverBuilder("r1"), null),
+            new RetrieverSource(new TestRetrieverBuilder("r2"), null)
+        );
+        int rankWindowSize = 5;
+        float[] weights = new float[] { 1.0f, 2.0f };
+        ScoreNormalizer[] normalizers = new ScoreNormalizer[] { IdentityScoreNormalizer.INSTANCE, IdentityScoreNormalizer.INSTANCE };
+        float minScore = 0f;
+
+        LinearRetrieverBuilder builder = new LinearRetrieverBuilder(sources, rankWindowSize, weights, normalizers, minScore);
+
+        ScoreDoc[] left = new ScoreDoc[] { new ScoreDoc(5, 1.0f, 0), new ScoreDoc(6, 2.0f, 0) };
+        ScoreDoc[] right = new ScoreDoc[] { new ScoreDoc(5, 3.0f, 0), new ScoreDoc(6, 1.0f, 0), new ScoreDoc(7, 0.5f, 0) };
+
+        RankDoc[] results = builder.combineInnerRetrieverResults(List.of(left, right), false);
+
+        assertEquals("Should have 3 combined docs", 3, results.length);
+
+        assertEquals("Doc 5 score", 7.0f, results[0].score, 0.001f);
+        assertEquals("Doc 5 ID", 5, results[0].doc);
+        assertEquals("Doc 5 rank", 1, results[0].rank);
+
+        assertEquals("Doc 6 score", 4.0f, results[1].score, 0.001f);
+        assertEquals("Doc 6 ID", 6, results[1].doc);
+        assertEquals("Doc 6 rank", 2, results[1].rank);
+
+        assertEquals("Doc 7 score", 1.0f, results[2].score, 0.001f);
+        assertEquals("Doc 7 ID", 7, results[2].doc);
+        assertEquals("Doc 7 rank", 3, results[2].rank);
+    }
+
+    public void testCombineAndFilterWithMinScore() throws IOException {
+        List<RetrieverSource> sources = List.of(
+            new RetrieverSource(new TestRetrieverBuilder("r1"), null),
+            new RetrieverSource(new TestRetrieverBuilder("r2"), null)
+        );
+        int rankWindowSize = 5;
+        float[] weights = new float[] { 1.0f, 1.0f };
+        ScoreNormalizer[] normalizers = new ScoreNormalizer[] { IdentityScoreNormalizer.INSTANCE, IdentityScoreNormalizer.INSTANCE };
+        final float minScoreThreshold = 1.5f;
+
+        LinearRetrieverBuilder builder = new LinearRetrieverBuilder(sources, rankWindowSize, weights, normalizers, minScoreThreshold);
+        assertEquals(minScoreThreshold, builder.getMinScore(), 0f);
+
+        ScoreDoc[] left = new ScoreDoc[] { new ScoreDoc(0, 1.0f, 0), new ScoreDoc(1, 0.8f, 0) };
+        ScoreDoc[] right = new ScoreDoc[] { new ScoreDoc(0, 2.0f, 0), new ScoreDoc(1, 0.6f, 0), new ScoreDoc(2, 1.8f, 0) };
+
+        RankDoc[] combinedRankDocs = builder.combineInnerRetrieverResults(List.of(left, right), false);
+        assertEquals("Combined docs count (already filtered)", 2, combinedRankDocs.length);
+
+        List<RankDoc> filteredDocs = Stream.of(combinedRankDocs).sorted().toList();
+
+        assertEquals("Filtered docs count", 2, filteredDocs.size());
+
+        boolean foundDoc0 = false;
+        boolean foundDoc2 = false;
+        for (RankDoc scoreDoc : filteredDocs) {
+            assertTrue("Score should be >= minScore", scoreDoc.score >= minScoreThreshold);
+            if (scoreDoc.doc == 0) {
+                assertEquals("Doc 0 score", 3.0f, scoreDoc.score, 0.001f);
+                foundDoc0 = true;
+            } else if (scoreDoc.doc == 2) {
+                assertEquals("Doc 2 score", 1.8f, scoreDoc.score, 0.001f);
+                foundDoc2 = true;
+            } else {
+                fail("Unexpected document ID returned: " + scoreDoc.doc + " (should have been filtered)");
+            }
+        }
+        assertTrue("Document 0 should have been found", foundDoc0);
+        assertTrue("Document 2 should have been found", foundDoc2);
+    }
+}