Merge pull request elastic#19972 from jimferenczi/dfs_explain

Fix explain output for dfs query

Author: jimczi

core/src/main/java/org/elasticsearch/search/internal/ContextIndexSearcher.java

@@ -133,6 +133,10 @@ public Weight createWeight(Query query, boolean needsScores) throws IOException
 
  @Override
  public Explanation explain(Query query, int doc) throws IOException {
+ if (aggregatedDfs != null) {
+ // dfs data is needed to explain the score
+ return super.explain(createNormalizedWeight(query, true), doc);
+ }
  return in.explain(query, doc);
  }
 

core/src/test/java/org/elasticsearch/search/basic/TransportTwoNodesSearchIT.java

@@ -60,6 +60,7 @@
 import static org.elasticsearch.index.query.QueryBuilders.termQuery;
 import static org.elasticsearch.search.builder.SearchSourceBuilder.searchSource;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailures;
+import static org.hamcrest.Matchers.endsWith;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
@@ -147,6 +148,10 @@ public void testDfsQueryThenFetch() throws Exception {
  for (int i = 0; i < hits.length; ++i) {
  SearchHit hit = hits[i];
  assertThat(hit.explanation(), notNullValue());
+ assertThat(hit.explanation().getDetails().length, equalTo(1));
+ assertThat(hit.explanation().getDetails()[0].getDetails().length, equalTo(2));
+ assertThat(hit.explanation().getDetails()[0].getDetails()[0].getDescription(),
+ endsWith("idf(docFreq=100, docCount=100)"));
  assertThat("id[" + hit.id() + "] -> " + hit.explanation().toString(), hit.id(), equalTo(Integer.toString(100 - total - i - 1)));
  }
  total += hits.length;
@@ -171,6 +176,10 @@ public void testDfsQueryThenFetchWithSort() throws Exception {
  for (int i = 0; i < hits.length; ++i) {
  SearchHit hit = hits[i];
  assertThat(hit.explanation(), notNullValue());
+ assertThat(hit.explanation().getDetails().length, equalTo(1));
+ assertThat(hit.explanation().getDetails()[0].getDetails().length, equalTo(2));
+ assertThat(hit.explanation().getDetails()[0].getDetails()[0].getDescription(),
+ endsWith("idf(docFreq=100, docCount=100)"));
  assertThat("id[" + hit.id() + "]", hit.id(), equalTo(Integer.toString(total + i)));
  }
  total += hits.length;
@@ -317,6 +326,10 @@ public void testDfsQueryAndFetch() throws Exception {
  SearchHit hit = searchResponse.getHits().hits()[i];
 // System.out.println(hit.shard() + ": " + hit.explanation());
  assertThat(hit.explanation(), notNullValue());
+ assertThat(hit.explanation().getDetails().length, equalTo(1));
+ assertThat(hit.explanation().getDetails()[0].getDetails().length, equalTo(2));
+ assertThat(hit.explanation().getDetails()[0].getDetails()[0].getDescription(),
+ endsWith("idf(docFreq=100, docCount=100)"));
 // assertThat("id[" + hit.id() + "]", hit.id(), equalTo(Integer.toString(100 - i - 1)));
  assertThat("make sure we don't have duplicates", expectedIds.remove(hit.id()), notNullValue());
  }