LUCENE-6042: fix CustomScoreQuery explain to properly factor boost

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1636552 13f79535-47bb-0310-9956-ffa450edef68

lucene/CHANGES.txt

@@ -204,6 +204,9 @@ Bug Fixes
 * LUCENE-6041: Remove sugar methods FieldInfo.isIndexed and
   FieldInfo.hasDocValues.  (Robert Muir, Mike McCandless)
 
+* LUCENE-6042: CustomScoreQuery explain was incorrect in some cases,
+  such as when nested inside a boolean query. (Denis Lantsman via Robert Muir)
+
 Documentation
 
 * LUCENE-5392: Add/improve analysis package documentation to reflect

lucene/core/src/test/org/apache/lucene/search/TestComplexExplanations.java

@@ -27,7 +27,7 @@ import org.apache.lucene.search.spans.*;
  * on the assumption that if the explanations work out right for them,
  * they should work for anything.
  */
-public class TestComplexExplanations extends TestExplanations {
+public class TestComplexExplanations extends BaseExplanationTestCase {
 
   /**
    * Override the Similarity used in our searcher with one that plays

lucene/core/src/test/org/apache/lucene/search/TestSimpleExplanations.java

@@ -22,7 +22,7 @@ import org.apache.lucene.index.Term;
 /**
  * TestExplanations subclass focusing on basic query types
  */
-public class TestSimpleExplanations extends TestExplanations {
+public class TestSimpleExplanations extends BaseExplanationTestCase {
 
   // we focus on queries that don't rewrite to other queries.
   // if we get those covered well, then the ones that rewrite should

lucene/core/src/test/org/apache/lucene/search/payloads/TestPayloadExplanations.java

@@ -20,14 +20,14 @@ package org.apache.lucene.search.payloads;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.similarities.DefaultSimilarity;
 import org.apache.lucene.search.similarities.Similarity;
-import org.apache.lucene.search.TestExplanations;
+import org.apache.lucene.search.BaseExplanationTestCase;
 import org.apache.lucene.search.spans.SpanQuery;
 import org.apache.lucene.util.BytesRef;
 
 /**
  * TestExplanations subclass focusing on payload queries
  */
-public class TestPayloadExplanations extends TestExplanations {
+public class TestPayloadExplanations extends BaseExplanationTestCase {
   private PayloadFunction functions[] = new PayloadFunction[] { 
       new AveragePayloadFunction(),
       new MinPayloadFunction(),

lucene/core/src/test/org/apache/lucene/search/spans/TestSpanExplanations.java

@@ -23,7 +23,7 @@ import org.apache.lucene.search.*;
 /**
  * TestExplanations subclass focusing on span queries
  */
-public class TestSpanExplanations extends TestExplanations {
+public class TestSpanExplanations extends BaseExplanationTestCase {
 
   /* simple SpanTermQueries */
   

lucene/queries/src/java/org/apache/lucene/queries/CustomScoreQuery.java

@@ -263,11 +263,11 @@ public class CustomScoreQuery extends Query {
         valSrcExpls[i] = valSrcWeights[i].explain(info, doc);
       }
       Explanation customExp = CustomScoreQuery.this.getCustomScoreProvider(info).customExplain(doc,subQueryExpl,valSrcExpls);
-      float sc = getBoost() * customExp.getValue();
+      float sc = queryWeight * customExp.getValue();
       Explanation res = new ComplexExplanation(
         true, sc, CustomScoreQuery.this.toString() + ", product of:");
       res.addDetail(customExp);
-      res.addDetail(new Explanation(getBoost(), "queryBoost")); // actually using the q boost as q weight (== weight value)
+      res.addDetail(new Explanation(queryWeight, "queryWeight"));
       return res;
     }
 

lucene/queries/src/test/org/apache/lucene/queries/TestCustomScoreExplanations.java

@@ -0,0 +1,53 @@
+package org.apache.lucene.queries;
+
+/*
+ * 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.index.Term;
+import org.apache.lucene.queries.function.FunctionQuery;
+import org.apache.lucene.queries.function.valuesource.ConstValueSource;
+import org.apache.lucene.search.BaseExplanationTestCase;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.TermQuery;
+
+public class TestCustomScoreExplanations extends BaseExplanationTestCase {
+  public void testOneTerm() throws Exception {
+    Query q = new TermQuery(new Term(FIELD, "w1"));
+    CustomScoreQuery csq = new CustomScoreQuery(q, new FunctionQuery(new ConstValueSource(5)));
+    qtest(csq, new int[] { 0,1,2,3 });
+  }
+  
+  public void testBoost() throws Exception {
+    Query q = new TermQuery(new Term(FIELD, "w1"));
+    CustomScoreQuery csq = new CustomScoreQuery(q, new FunctionQuery(new ConstValueSource(5)));
+    csq.setBoost(4);
+    qtest(csq, new int[] { 0,1,2,3 });
+  }
+  
+  public void testTopLevelBoost() throws Exception {
+    Query q = new TermQuery(new Term(FIELD, "w1"));
+    CustomScoreQuery csq = new CustomScoreQuery(q, new FunctionQuery(new ConstValueSource(5)));
+    BooleanQuery bq = new BooleanQuery();
+    bq.add(new MatchAllDocsQuery(), BooleanClause.Occur.MUST);
+    bq.add(csq, BooleanClause.Occur.MUST);
+    bq.setBoost(6);
+    qtest(bq, new int[] { 0,1,2,3 });
+  }
+}

lucene/test-framework/src/java/org/apache/lucene/search/BaseExplanationTestCase.java

@@ -48,7 +48,7 @@ import org.junit.BeforeClass;
  *
  * @see "Subclasses for actual tests"
  */
-public class TestExplanations extends LuceneTestCase {
+public abstract class BaseExplanationTestCase extends LuceneTestCase {
   protected static IndexSearcher searcher;
   protected static IndexReader reader;
   protected static Directory directory;
@@ -211,12 +211,4 @@ public class TestExplanations extends LuceneTestCase {
     bq.add(new TermQuery(new Term(FIELD,"w1")), BooleanClause.Occur.SHOULD);
     return bq;
   }
-  
-  /**
-   * Placeholder: JUnit freaks if you don't have one test ... making
-   * class abstract doesn't help
-   */
-  public void testNoop() {
-    /* NOOP */
-  }
 }