Add Composite to AggregationBuilders (#38207)

Author: polyfractal

client/rest-high-level/src/test/java/org/elasticsearch/client/SearchIT.java

@@ -59,7 +59,11 @@
 import org.elasticsearch.script.mustache.SearchTemplateRequest;
 import org.elasticsearch.script.mustache.SearchTemplateResponse;
 import org.elasticsearch.search.SearchHit;
+import org.elasticsearch.search.aggregations.AggregationBuilders;
 import org.elasticsearch.search.aggregations.BucketOrder;
+import org.elasticsearch.search.aggregations.bucket.composite.CompositeAggregation;
+import org.elasticsearch.search.aggregations.bucket.composite.CompositeValuesSourceBuilder;
+import org.elasticsearch.search.aggregations.bucket.composite.TermsValuesSourceBuilder;
 import org.elasticsearch.search.aggregations.bucket.range.Range;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms;
@@ -275,6 +279,34 @@ public void testSearchWithTermsAgg() throws IOException {
         assertEquals(0, type2.getAggregations().asList().size());
     }
 
+    public void testSearchWithCompositeAgg() throws IOException {
+        SearchRequest searchRequest = new SearchRequest();
+        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
+        List<CompositeValuesSourceBuilder<?>> sources
+            = Collections.singletonList(new TermsValuesSourceBuilder("terms").field("type.keyword").missingBucket(true).order("asc"));
+        searchSourceBuilder.aggregation(AggregationBuilders.composite("composite", sources));
+        searchSourceBuilder.size(0);
+        searchRequest.source(searchSourceBuilder);
+        searchRequest.indices("index");
+        SearchResponse searchResponse = execute(searchRequest, highLevelClient()::search, highLevelClient()::searchAsync);
+        assertSearchHeader(searchResponse);
+        assertNull(searchResponse.getSuggest());
+        assertEquals(Collections.emptyMap(), searchResponse.getProfileResults());
+        assertEquals(0, searchResponse.getHits().getHits().length);
+        assertEquals(Float.NaN, searchResponse.getHits().getMaxScore(), 0f);
+        CompositeAggregation compositeAgg = searchResponse.getAggregations().get("composite");
+        assertEquals("composite", compositeAgg.getName());
+        assertEquals(2, compositeAgg.getBuckets().size());
+        CompositeAggregation.Bucket bucket1 = compositeAgg.getBuckets().get(0);
+        assertEquals(3, bucket1.getDocCount());
+        assertEquals("{terms=type1}", bucket1.getKeyAsString());
+        assertEquals(0, bucket1.getAggregations().asList().size());
+        CompositeAggregation.Bucket bucket2 = compositeAgg.getBuckets().get(1);
+        assertEquals(2, bucket2.getDocCount());
+        assertEquals("{terms=type2}", bucket2.getKeyAsString());
+        assertEquals(0, bucket2.getAggregations().asList().size());
+    }
+
     public void testSearchWithRangeAgg() throws IOException {
         {
             SearchRequest searchRequest = new SearchRequest();

server/src/main/java/org/elasticsearch/search/aggregations/AggregationBuilders.java

@@ -23,6 +23,8 @@
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.search.aggregations.bucket.adjacency.AdjacencyMatrix;
 import org.elasticsearch.search.aggregations.bucket.adjacency.AdjacencyMatrixAggregationBuilder;
+import org.elasticsearch.search.aggregations.bucket.composite.CompositeAggregationBuilder;
+import org.elasticsearch.search.aggregations.bucket.composite.CompositeValuesSourceBuilder;
 import org.elasticsearch.search.aggregations.bucket.filter.Filter;
 import org.elasticsearch.search.aggregations.bucket.filter.FilterAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.filter.Filters;
@@ -88,6 +90,7 @@
 import org.elasticsearch.search.aggregations.metrics.MedianAbsoluteDeviationAggregationBuilder;
 import org.elasticsearch.search.aggregations.metrics.MedianAbsoluteDeviation;
 
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -368,4 +371,11 @@ public static GeoCentroidAggregationBuilder geoCentroid(String name) {
     public static ScriptedMetricAggregationBuilder scriptedMetric(String name) {
         return new ScriptedMetricAggregationBuilder(name);
     }
+
+    /**
+     * Create a new {@link CompositeAggregationBuilder} aggregation with the given name.
+     */
+    public static CompositeAggregationBuilder composite(String name, List<CompositeValuesSourceBuilder<?>> sources) {
+        return new CompositeAggregationBuilder(name, sources);
+    }
 }