From 3335c98eb647d50c04a3f747824b74e7f575921e Mon Sep 17 00:00:00 2001
From: Rene Cordier <rene.cordier@gmail.com>
Date: Fri, 24 Jun 2022 05:38:45 +0700
Subject: [PATCH] Sort field in Hit deserializer should handle null events
 (#169)

Signed-off-by: Rene Cordier <rcordier@linagora.com>
---
 .../client/json/JsonpDeserializer.java        |  4 ++++
 .../client/json/JsonpDeserializerBase.java    | 24 +++++++++++++++++++
 .../client/opensearch/core/search/Hit.java    |  2 +-
 .../opensearch/model/BuiltinTypesTest.java    | 22 +++++++++++++++++
 4 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializer.java b/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializer.java
index f827ff56d5c44..3c12aa2884242 100644
--- a/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializer.java
+++ b/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializer.java
@@ -204,6 +204,10 @@ static JsonpDeserializer<Integer> intOrNullDeserializer(int defaultValue) {
         return new JsonpDeserializerBase.IntOrNullDeserializer(defaultValue);
     }
 
+    static JsonpDeserializer<String> stringOrNullDeserializer() {
+        return new JsonpDeserializerBase.StringOrNullDeserializer();
+    }
+
     static JsonpDeserializer<Number> numberDeserializer() {
         return JsonpDeserializerBase.NUMBER;
     }
diff --git a/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializerBase.java b/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializerBase.java
index 4319059de4457..d706f8ec727c9 100644
--- a/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializerBase.java
+++ b/java-client/src/main/java/org/opensearch/client/json/JsonpDeserializerBase.java
@@ -238,6 +238,30 @@ public Integer deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
         }
     }
 
+    static final class StringOrNullDeserializer extends JsonpDeserializerBase<String> {
+        static final EnumSet<Event> nativeEvents = EnumSet.of(Event.VALUE_STRING, Event.VALUE_NULL);
+        static final EnumSet<Event> acceptedEvents = EnumSet.of(Event.KEY_NAME, Event.VALUE_STRING,
+            Event.VALUE_NUMBER, Event.VALUE_FALSE, Event.VALUE_TRUE, Event.VALUE_NULL);
+
+        StringOrNullDeserializer() {
+            super(acceptedEvents, nativeEvents);
+        }
+
+        @Override
+        public String deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
+            if (event == Event.VALUE_NULL) {
+                return null;
+            }
+            if (event == Event.VALUE_TRUE) {
+                return "true";
+            }
+            if (event == Event.VALUE_FALSE) {
+                return "false";
+            }
+            return parser.getString();
+        }
+    }
+
     static final JsonpDeserializer<Double> DOUBLE_OR_NAN =
         new JsonpDeserializerBase<Double>(
             EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_STRING, Event.VALUE_NULL),
diff --git a/java-client/src/main/java/org/opensearch/client/opensearch/core/search/Hit.java b/java-client/src/main/java/org/opensearch/client/opensearch/core/search/Hit.java
index 828ed15f72c42..5bd4893b4724a 100644
--- a/java-client/src/main/java/org/opensearch/client/opensearch/core/search/Hit.java
+++ b/java-client/src/main/java/org/opensearch/client/opensearch/core/search/Hit.java
@@ -775,7 +775,7 @@ protected static <TDocument> void setupHitDeserializer(ObjectDeserializer<Hit.Bu
 		op.add(Builder::seqNo, JsonpDeserializer.longDeserializer(), "_seq_no");
 		op.add(Builder::primaryTerm, JsonpDeserializer.longDeserializer(), "_primary_term");
 		op.add(Builder::version, JsonpDeserializer.longDeserializer(), "_version");
-		op.add(Builder::sort, JsonpDeserializer.arrayDeserializer(JsonpDeserializer.stringDeserializer()), "sort");
+		op.add(Builder::sort, JsonpDeserializer.arrayDeserializer(JsonpDeserializer.stringOrNullDeserializer()), "sort");
 
 	}
 
diff --git a/java-client/src/test/java/org/opensearch/client/opensearch/model/BuiltinTypesTest.java b/java-client/src/test/java/org/opensearch/client/opensearch/model/BuiltinTypesTest.java
index 6a29ce45f8606..42930ce1026e5 100644
--- a/java-client/src/test/java/org/opensearch/client/opensearch/model/BuiltinTypesTest.java
+++ b/java-client/src/test/java/org/opensearch/client/opensearch/model/BuiltinTypesTest.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.client.opensearch.model;
 
+import org.opensearch.client.json.JsonpDeserializer;
 import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch._types.SortOptions;
 import org.opensearch.client.opensearch._types.SortOrder;
@@ -42,8 +43,12 @@
 import org.opensearch.client.opensearch.indices.IndexSettings;
 import org.junit.Test;
 
+import java.io.StringReader;
+import java.util.ArrayList;
 import java.util.List;
 
+import jakarta.json.stream.JsonParser;
+
 public class BuiltinTypesTest extends ModelTestCase {
 
     @Test
@@ -229,4 +234,21 @@ public void testNullableInt() {
         assertEquals(0, stats.maxLength());
         assertEquals(0.0, stats.entropy(), 0.01);
     }
+
+    @Test
+    public void testNullableStringInArray() {
+        // stringOrNullDeserializer allows to handle null events in string arrays
+        String json = "[\"lettuce\", null, \"tomato\"]";
+        JsonParser jsonParser = mapper.jsonProvider().createParser(new StringReader(json));
+        JsonpDeserializer<String> stringDeserializer = JsonpDeserializer.stringOrNullDeserializer();
+
+        List<String> result = JsonpDeserializer.arrayDeserializer(stringDeserializer).deserialize(jsonParser, mapper);
+
+        List<String> expected = new ArrayList<>();
+        expected.add("lettuce");
+        expected.add(null);
+        expected.add("tomato");
+
+        assertEquals(result, expected);
+    }
 }