SOLR-13679:Fix default style of [explain] registered in solrconfig.xml

solr/CHANGES.txt

@@ -143,6 +143,9 @@ Other Changes
 
 * SOLR-13659: Refactor CacheConfig to lazily load the the implementation class (noble)
 
+* SOLR-13679: Default style of ExplainDocTransformer registered via solrconfig.xml should be same as default style
+  of ExplainDocTransformer registered in defaultFactories (Munendra S N)
+
 ==================  8.2.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.

solr/core/src/java/org/apache/solr/response/transform/ExplainAugmenterFactory.java

@@ -33,13 +33,13 @@ import org.apache.solr.util.SolrPluginUtils;
  */
 public class ExplainAugmenterFactory extends TransformerFactory
 {
-  public static enum Style {
+  public enum Style {
     nl,
     text,
     html
-  };
+  }
 
-  protected Style defaultStyle = null;
+  protected Style defaultStyle = Style.text;
 
   @Override
   public void init(NamedList args) {
@@ -47,13 +47,9 @@ public class ExplainAugmenterFactory extends TransformerFactory
     if( defaultUserArgs != null ) {
       defaultStyle = getStyle( defaultUserArgs );
     }
-    else {
-      defaultStyle = Style.nl;
-    }
   }
 
-  public static Style getStyle( String str )
-  {
+  public static Style getStyle( String str ) {
     try {
       return Style.valueOf( str );
     }
@@ -66,7 +62,7 @@ public class ExplainAugmenterFactory extends TransformerFactory
   @Override
   public DocTransformer create(String field, SolrParams params, SolrQueryRequest req) {
     String s = params.get("style");
-    Style style = (s==null)?defaultStyle:getStyle(s);
+    Style style = (s == null) ? defaultStyle : getStyle(s);
     return new ExplainAugmenter( field, style );
   }
 
@@ -123,6 +119,3 @@ public class ExplainAugmenterFactory extends TransformerFactory
     }
   }
 }
-
-
-

solr/core/src/test-files/solr/collection1/conf/solrconfig.xml

@@ -561,7 +561,13 @@
     </lst>
   </initParams>
 
-  
+  <transformer name="explain1" class="org.apache.solr.response.transform.ExplainAugmenterFactory" />
+  <transformer name="explainText" class="org.apache.solr.response.transform.ExplainAugmenterFactory" >
+    <str name="args">text</str>
+  </transformer>
+  <transformer name="explainNL" class="org.apache.solr.response.transform.ExplainAugmenterFactory" >
+    <str name="args">nl</str>
+  </transformer>
 
 </config>
 

solr/core/src/test/org/apache/solr/response/transform/TestExplainDocTransformer.java

@@ -0,0 +1,75 @@
+/*
+ * 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.solr.response.transform;
+
+
+import org.apache.solr.SolrTestCaseJ4;
+import org.junit.After;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class TestExplainDocTransformer extends SolrTestCaseJ4 {
+
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig.xml","schema.xml");
+
+    assertU(add(doc("id", "1", "name_s", "john", "title_s", "Director", "dept_s","Engineering",
+        "text_t","These guys develop stuff")));
+    assertU(add(doc("id", "2", "name_s", "mark", "title_s", "VP", "dept_s","Marketing",
+        "text_t","These guys make you look good")));
+    assertU(add(doc("id", "3", "name_s", "nancy", "title_s", "MTS", "dept_s","Sales",
+        "text_t","These guys sell stuff")));
+    assertU(add(doc("id", "4", "name_s", "dave", "title_s", "MTS", "dept_s","Support",
+        "text_t","These guys help customers")));
+    assertU(add(doc("id", "5", "name_s", "tina", "title_s", "VP", "dept_s","Engineering",
+        "text_t","These guys develop stuff")));
+    assertU(commit());
+  }
+
+  @After
+  public void cleanup() throws Exception {
+    assertU(delQ("*:*"));
+    assertU(commit());
+  }
+
+  @Test
+  public void testStyle() throws Exception {
+    // this doesn't validate the explain response but checks if explain response is returned in expected format
+
+    // when not style is passed then default style should be used
+    assertQ(req("q", "*:*", "fl", "id,[explain]"), "//result/doc[1]/str[@name='id'][.='1']",
+        "boolean(//result/doc[1]/str[@name='[explain]'])");
+
+    // doc transformer defined in solrconfig without style
+    assertQ(req("q", "*:*", "fl", "id,[explain1]"), "//result/doc[1]/str[@name='id'][.='1']",
+        "boolean(//result/doc[1]/str[@name='[explain1]'])");
+
+    // doc transformer defined in solrconfig with style=nl
+    assertQ(req("q", "*:*", "fl", "id,[explainNL]"), "//result/doc[1]/str[@name='id'][.='1']",
+        "boolean(//result/doc[1]/lst[@name='[explainNL]'])");
+
+    // doc transformer defined in solrconfig with style=nl
+    assertQ(req("q", "*:*", "fl", "id,[explainText]"), "//result/doc[1]/str[@name='id'][.='1']",
+        "boolean(//result/doc[1]/str[@name='[explainText]'])");
+
+    // passing style as parameter at runtime
+    assertQ(req("q", "*:*", "fl", "id,[explainText style=nl]"), "//result/doc[1]/str[@name='id'][.='1']",
+        "boolean(//result/doc[1]/lst[@name='[explainText]'])");
+  }
+}