Adds unit test for sampler aggregation

Relates to #22278

1 files changed, 79 insertions, 0 deletions

diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/sampler/SamplerAggregatorTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/sampler/SamplerAggregatorTests.java
new file mode 100644
index 0000000000..5db4caaf65
--- /dev/null
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/sampler/SamplerAggregatorTests.java
@@ -0,0 +1,79 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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.elasticsearch.search.aggregations.bucket.sampler;
+
+import org.apache.lucene.analysis.standard.StandardAnalyzer;
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.document.SortedNumericDocValuesField;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.RandomIndexWriter;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.TermQuery;
+import org.apache.lucene.store.Directory;
+import org.elasticsearch.index.analysis.AnalyzerScope;
+import org.elasticsearch.index.analysis.NamedAnalyzer;
+import org.elasticsearch.index.mapper.MappedFieldType;
+import org.elasticsearch.index.mapper.NumberFieldMapper;
+import org.elasticsearch.index.mapper.TextFieldMapper.TextFieldType;
+import org.elasticsearch.search.aggregations.AggregatorTestCase;
+import org.elasticsearch.search.aggregations.metrics.min.Min;
+import org.elasticsearch.search.aggregations.metrics.min.MinAggregationBuilder;
+
+import java.io.IOException;
+
+public class SamplerAggregatorTests extends AggregatorTestCase {
+    /**
+     * Uses the sampler aggregation to find the minimum value of a field out of the top 3 scoring documents in a search.
+     */
+    public void testSampler() throws IOException {
+        TextFieldType textFieldType = new TextFieldType();
+        textFieldType.setIndexAnalyzer(new NamedAnalyzer("foo", AnalyzerScope.GLOBAL, new StandardAnalyzer()));
+        MappedFieldType numericFieldType = new NumberFieldMapper.NumberFieldType(NumberFieldMapper.NumberType.LONG);
+        numericFieldType.setName("int");
+
+        try (Directory dir = newDirectory();
+                RandomIndexWriter w = new RandomIndexWriter(random(), dir)) {
+            for (long value : new long[] {7, 3, -10, -6, 5, 50}) {
+                Document doc = new Document();
+                StringBuilder text = new StringBuilder();
+                for (int i = 0; i < value; i++) {
+                    text.append("good ");
+                }
+                doc.add(new Field("text", text.toString(), textFieldType));
+                doc.add(new SortedNumericDocValuesField("int", value));
+                w.addDocument(doc);
+            }
+
+            SamplerAggregationBuilder aggBuilder = new SamplerAggregationBuilder("sampler")
+                    .shardSize(3)
+                    .subAggregation(new MinAggregationBuilder("min")
+                            .field("int"));
+            try (IndexReader reader = w.getReader()) {
+                IndexSearcher searcher = new IndexSearcher(reader);
+                Sampler sampler = searchAndReduce(searcher, new TermQuery(new Term("text", "good")), aggBuilder, textFieldType,
+                        numericFieldType);
+                Min min = sampler.getAggregations().get("min");
+                assertEquals(5.0, min.getValue(), Double.MIN_NORMAL);
+            }
+        }
+    }
+}