From 049129c7b64eef8c45f9e2f4c9bf165c8724c5a7 Mon Sep 17 00:00:00 2001
From: Jay Deng <jayd0104@gmail.com>
Date: Thu, 22 Jun 2023 09:46:13 -0700
Subject: [PATCH] Return null for aggregations factory even if empty aggs is
 present in search source (#8206)

* Return null for aggregations factory even if empty aggs is present in search source

Signed-off-by: Jay Deng <jayd0104@gmail.com>

* Update rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/60_empty.yml

Co-authored-by: Andriy Redko <drreta@gmail.com>
Signed-off-by: Jay Deng <jayd0104@gmail.com>

---------

Signed-off-by: Jay Deng <jayd0104@gmail.com>
Co-authored-by: Andriy Redko <drreta@gmail.com>
---
 .../test/search.aggregation/60_empty.yml      | 29 +++++++++++++++++++
 .../aggregations/AggregatorFactories.java     |  2 +-
 2 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/60_empty.yml

diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/60_empty.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/60_empty.yml
new file mode 100644
index 0000000000000..7b374e3f6a409
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/60_empty.yml
@@ -0,0 +1,29 @@
+---
+"Empty aggs Body":
+  - do:
+      index:
+        index: test
+        id: 1
+        body: { "double" : 42 }
+
+  - do:
+      index:
+        index: test
+        id: 2
+        body: { "double" : 100 }
+
+  - do:
+      index:
+        index: test
+        id: 3
+        body: { "double" : 50 }
+
+  - do:
+      indices.refresh: {}
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body: { "size" : 0, "aggs" : { } }
+
+  - match: { hits.total: 3 }
diff --git a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
index f760070a9b650..e57776fd78c49 100644
--- a/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
+++ b/server/src/main/java/org/opensearch/search/aggregations/AggregatorFactories.java
@@ -235,7 +235,7 @@ private static AggregatorFactories.Builder parseAggregators(XContentParser parse
             }
         }
 
-        return factories;
+        return factories.count() > 0 ? factories : null;
     }
 
     public static final AggregatorFactories EMPTY = new AggregatorFactories(new AggregatorFactory[0]);