Add test about nested aggregation

Signed-off-by: kkewwei <[email protected]>

CHANGELOG.md

@@ -113,6 +113,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Rename `Bytes` component to `StorageType` ([#552](https://github.com/opensearch-project/opensearch-api-specification/pull/552))
 - Rename `ByteSize` to `StorageSize` ([#552](https://github.com/opensearch-project/opensearch-api-specification/pull/552))
 - Split `Percentage` into `PercentageNumber`, `PercentageString` ([#573](https://github.com/opensearch-project/opensearch-api-specification/pull/573))
+- Add test about nested aggregation ([#576](https://github.com/opensearch-project/opensearch-api-specification/issues/576))
 
 ### Deprecated
 

tests/default/_core/aggregation/nested.yaml

@@ -0,0 +1,100 @@
+$schema: ../../../../json_schemas/test_story.schema.yaml
+
+description: Test aggregation endpoints with nested.
+prologues:
+  - path: movies
+    method: PUT
+    request_body:
+      payload:
+        mappings:
+          properties:
+            a:
+              type: nested
+              properties:
+                b1:
+                  type: keyword
+                b2:
+                  type: nested
+                  properties:
+                    c:
+                      type: nested
+                      properties:
+                        d:
+                          type: keyword
+
+chapters:
+  - synopsis: Bulk document.
+    path: /_bulk
+    method: POST
+    request_body:
+      content_type: application/x-ndjson
+      payload:
+        - {index: {"_index": "movies", "_id": "0"}}
+        - {"a": { "b1": "b11", "b2": { "c": { "d": "d1" } }}}
+        - {"index": {"_index": "movies", "_id": "1"}}
+        - {"a": { "b1": "b12", "b2": { "c": { "d": "d2" } }}}
+
+  - synopsis: aggregation with nested.
+    path: /movies/_search
+    method: POST
+    request_body:
+      payload:
+        size: 0
+        aggs:
+          nested_agg:
+            nested:
+              path: a
+            aggs:
+              a_b1:
+                terms:
+                  field: a.b1
+                aggs:
+                  c:
+                    nested:
+                      path: a.b2.c
+                    aggs:
+                      d:
+                        terms:
+                         field: a.b2.c.d
+
+    response:
+      status: 200
+      payload:
+        timed_out: false
+        hits:
+          total:
+            value: 2
+            relation: eq
+          hits: []
+        aggregations:
+          nested_agg:
+            doc_count: 2
+            a_b1:
+              doc_count_error_upper_bound: 0
+              sum_other_doc_count: 0
+              buckets:
+                - key: b11
+                  doc_count: 1
+                  c:
+                    doc_count: 1
+                    d:
+                      doc_count_error_upper_bound: 0
+                      sum_other_doc_count: 0
+                      buckets:
+                        - key: d1
+                          doc_count: 1
+                - key: b12
+                  doc_count: 1
+                  c:
+                    doc_count: 1
+                    d:
+                      doc_count_error_upper_bound: 0
+                      sum_other_doc_count: 0
+                      buckets:
+                        - key: d1
+                          doc_count: 1
+
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]