Test explaining sort after rename

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

integ-test/src/test/java/org/opensearch/sql/ppl/ExplainIT.java

@@ -142,6 +142,23 @@ public void testSortThenAggregatePushDownExplain() throws IOException {
                 + "| stats avg(balance) by state"));
   }
 
+  @Test
+  public void testSortWithRenameExplain() throws IOException {
+    String expected =
+        isCalciteEnabled()
+            ? loadFromFile("expectedOutput/calcite/explain_sort_rename_push.json")
+            : loadFromFile("expectedOutput/ppl/explain_sort_rename_push.json");
+
+    assertJsonEqualsIgnoreId(
+        expected,
+        explainQueryToString(
+            "source=opensearch-sql_test_index_account "
+                + "| rename firstname as name "
+                + "| eval alias = name "
+                + "|  sort alias "
+                + "| fields alias"));
+  }
+
   @Test
   public void testLimitPushDownExplain() throws IOException {
     String expected =

integ-test/src/test/resources/expectedOutput/calcite/explain_sort_rename_push.json

@@ -0,0 +1,6 @@
+{
+  "calcite": {
+    "logical": "LogicalSort(sort0=[$0], dir0=[ASC])\n  LogicalProject(alias=[$17])\n    LogicalSort(sort0=[$17], dir0=[ASC])\n      LogicalProject(account_number=[$0], name=[$1], address=[$2], balance=[$3], gender=[$4], city=[$5], employer=[$6], state=[$7], age=[$8], email=[$9], lastname=[$10], _id=[$11], _index=[$12], _score=[$13], _maxscore=[$14], _sort=[$15], _routing=[$16], alias=[$1])\n        CalciteLogicalIndexScan(table=[[OpenSearch, opensearch-sql_test_index_account]])\n",
+    "physical": "CalciteEnumerableIndexScan(table=[[OpenSearch, opensearch-sql_test_index_account]], PushDownContext=[[PROJECT->[firstname], SORT->[{\n  \"firstname.keyword\" : {\n    \"order\" : \"asc\",\n    \"missing\" : \"_last\"\n  }\n}]], OpenSearchRequestBuilder(sourceBuilder={\"from\":0,\"timeout\":\"1m\",\"_source\":{\"includes\":[\"firstname\"],\"excludes\":[]},\"sort\":[{\"firstname.keyword\":{\"order\":\"asc\",\"missing\":\"_last\"}}]}, requestedTotalSize=2147483647, pageSize=null, startFrom=0)])\n"
+  }
+}

integ-test/src/test/resources/expectedOutput/ppl/explain_sort_rename_push.json

@@ -0,0 +1,50 @@
+{
+  "root": {
+    "name": "ProjectOperator",
+    "description": {
+      "fields": "[alias]"
+    },
+    "children": [
+      {
+        "name": "SortOperator",
+        "description": {
+          "sortList": {
+            "alias": {
+              "sortOrder": "ASC",
+              "nullOrder": "NULL_FIRST"
+            }
+          }
+        },
+        "children": [
+          {
+            "name": "OpenSearchEvalOperator",
+            "description": {
+              "expressions": {
+                "alias": "name"
+              }
+            },
+            "children": [
+              {
+                "name": "RenameOperator",
+                "description": {
+                  "mapping": {
+                    "firstname": "name"
+                  }
+                },
+                "children": [
+                  {
+                    "name": "OpenSearchIndexScan",
+                    "description": {
+                      "request": "OpenSearchQueryRequest(indexName=opensearch-sql_test_index_account, sourceBuilder={\"from\":0,\"size\":10000,\"timeout\":\"1m\"}, needClean=true, searchDone=false, pitId=s9y3QQEhb3BlbnNlYXJjaC1zcWxfdGVzdF9pbmRleF9hY2NvdW50Fndla1VpMi1kVHh5Qi1lYnhPQnlSbXcAFkU4Qm9UVURIUWI2a3pjNkhmQkxvc2cAAAAAAAAAAAsWcnUyVHZfNk1SeC1DMFNFdGtPcDN4QQEWd2VrVWkyLWRUeHlCLWVieE9CeVJtdwAA, cursorKeepAlive=1m, searchAfter=null, searchResponse=null)"
+                    },
+                    "children": []
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+}