Fix bug of nested field format issue in JDBC response

core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AggregateFunction.java

@@ -16,6 +16,7 @@
 package com.amazon.opendistroforelasticsearch.sql.ast.expression;
 
 import com.amazon.opendistroforelasticsearch.sql.ast.AbstractNodeVisitor;
+import com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils;
 import java.util.Collections;
 import java.util.List;
 import lombok.EqualsAndHashCode;
@@ -57,6 +58,6 @@ public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
 
   @Override
   public String toString() {
-    return String.format("%s(%s)", funcName, field);
+    return StringUtils.format("%s(%s)", funcName, field);
   }
 }

core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValue.java

@@ -42,7 +42,11 @@ public static ExprTupleValue fromExprValueMap(Map<String, ExprValue> map) {
 
   @Override
   public Object value() {
-    return valueMap;
+    LinkedHashMap<String, Object> resultMap = new LinkedHashMap<>();
+    for (Entry<String, ExprValue> entry : valueMap.entrySet()) {
+      resultMap.put(entry.getKey(), entry.getValue().value());
+    }
+    return resultMap;
   }
 
   @Override

elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/data/value/ElasticsearchExprValueFactoryTest.java

@@ -272,7 +272,7 @@ public void constructUnsupportedTypeThrowException() {
   }
 
   public Map<String, ExprValue> tupleValue(String jsonString) {
-    return (Map<String, ExprValue>) exprValueFactory.construct(jsonString).value();
+    return exprValueFactory.construct(jsonString).tupleValue();
   }
 
   private ExprValue constructFromObject(String fieldName, Object value) {

legacy/src/test/java/com/amazon/opendistroforelasticsearch/sql/legacy/unittest/planner/QueryPlannerTest.java

@@ -23,6 +23,7 @@
 import com.amazon.opendistroforelasticsearch.sql.legacy.domain.JoinSelect;
 import com.amazon.opendistroforelasticsearch.sql.legacy.esdomain.LocalClusterState;
 import com.amazon.opendistroforelasticsearch.sql.legacy.exception.SqlParseException;
+import com.amazon.opendistroforelasticsearch.sql.legacy.metrics.Metrics;
 import com.amazon.opendistroforelasticsearch.sql.legacy.parser.ElasticSqlExprParser;
 import com.amazon.opendistroforelasticsearch.sql.legacy.parser.SqlParser;
 import com.amazon.opendistroforelasticsearch.sql.legacy.plugin.SqlSettings;
@@ -140,6 +141,8 @@ public SearchResponse answer(InvocationOnMock invocation) {
 
         returnMockResponse(SCROLL_ID1, response1);
         returnMockResponse(SCROLL_ID2, response2);
+
+        Metrics.getInstance().registerDefaultMetrics();
     }
 
     private void returnMockResponse(String scrollId, SearchResponse response) {

protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatterTest.java

@@ -109,6 +109,27 @@ void formatResponseWithMissingValue() {
         formatter.format(response));
   }
 
+  @Test
+  void formatResponseWithTupleValue() {
+    QueryResult response =
+        new QueryResult(
+            schema,
+            Arrays.asList(
+                tupleValue(ImmutableMap
+                    .of("name", "Smith",
+                        "address", ImmutableMap.of("state", "WA", "street",
+                            ImmutableMap.of("city", "seattle"))))));
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
+
+    assertEquals(
+        "{\"schema\":[{\"name\":\"firstname\",\"type\":\"string\"},"
+            + "{\"name\":\"age\",\"type\":\"integer\"}],"
+            + "\"datarows\":[[\"Smith\",{\"state\":\"WA\",\"street\":{\"city\":\"seattle\"}}]],"
+            + "\"total\":1,\"size\":1}",
+        formatter.format(response));
+  }
+
+
   @Test
   void formatError() {
     SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);