v1-0003-Add-jsonpath-.join-sep-method.patch

From 892f5574b251773a3cb8f14b5e18902bf6871200 Mon Sep 17 00:00:00 2001
From: Florents Tselai <florents.tselai@gmail.com>
Date: Mon, 13 Apr 2026 12:07:46 +0300
Subject: [PATCH v1 3/3] Add jsonpath $.join(sep) method

---
 doc/src/sgml/func/func-json.sgml              |  18 +++
 src/backend/utils/adt/jsonpath.c              |  22 ++++
 src/backend/utils/adt/jsonpath_exec.c         | 111 ++++++++++++++++++
 src/backend/utils/adt/jsonpath_gram.y         |   7 +-
 src/backend/utils/adt/jsonpath_scan.l         |   1 +
 src/include/utils/jsonpath.h                  |   1 +
 src/test/regress/expected/jsonb_jsonpath.out  |  80 +++++++++++++
 src/test/regress/expected/jsonpath.out        |  32 +++++
 .../regress/expected/sqljson_queryfuncs.out   |   1 +
 src/test/regress/sql/jsonb_jsonpath.sql       |  28 +++++
 src/test/regress/sql/jsonpath.sql             |   7 ++
 src/test/regress/sql/sqljson_queryfuncs.sql   |   1 +
 12 files changed, 308 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func/func-json.sgml b/doc/src/sgml/func/func-json.sgml
index 7aad2d69a88..715bdf62578 100644
--- a/doc/src/sgml/func/func-json.sgml
+++ b/doc/src/sgml/func/func-json.sgml
@@ -2959,6 +2959,24 @@ ERROR:  jsonpath member accessor can only be applied to an object
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <replaceable>array</replaceable> <literal>.</literal> <literal>join(separator [, null_string])</literal>
+        <returnvalue>string</returnvalue>
+       </para>
+        <para>
+         Concatenates the elements of an array into a single string using the
+         specified separator. If the optional <literal>null_string</literal>
+         argument is provided, it replaces JSON <literal>null</literal> values;
+         otherwise, <literal>null</literal> values are skipped. The input must
+         be an array consisting only of strings or <literal>null</literal> values.
+        </para>
+        <para>
+         <literal>jsonb_path_query('["a", null, "c"]', '$.join("-", "N/A")')</literal>
+         <returnvalue>"a-N/A-c"</returnvalue>
+        </para></entry>
+      </row>
+
      </tbody>
     </tgroup>
    </table>
diff --git a/src/backend/utils/adt/jsonpath.c b/src/backend/utils/adt/jsonpath.c
index d14fe450b6b..b501f197964 100644
--- a/src/backend/utils/adt/jsonpath.c
+++ b/src/backend/utils/adt/jsonpath.c
@@ -330,6 +330,7 @@ flattenJsonPathParseItem(StringInfo buf, int *result, struct Node *escontext,
 			}
 			break;
 		case jpiStrSplit:
+		case jpiStrJoin:
 			{
 				/* Reserve space for left and right arg positions */
 				int32		left = reserveSpaceForItemPointer(buf);
@@ -946,6 +947,20 @@ printJsonPathItem(StringInfo buf, JsonPathItem *v, bool inKey,
 			printJsonPathItem(buf, &elem, false, false);
 			appendStringInfoChar(buf, ')');
 			break;
+		case jpiStrJoin:
+			appendStringInfoString(buf, ".join(");
+			jspGetLeftArg(v, &elem);
+			printJsonPathItem(buf, &elem, false, false);
+
+			/* Check if null_string was provided. */
+			if (v->content.args.right != 0)
+			{
+				appendStringInfoString(buf, ", ");
+				jspGetRightArg(v, &elem);
+				printJsonPathItem(buf, &elem, false, false);
+			}
+			appendStringInfoChar(buf, ')');
+			break;
 		default:
 			elog(ERROR, "unrecognized jsonpath item type: %d", v->type);
 	}
@@ -1049,6 +1064,8 @@ jspOperationName(JsonPathItemType type)
 			return "translate";
 		case jpiStrSplit:
 			return "split";
+		case jpiStrJoin:
+			return "join";
 		default:
 			elog(ERROR, "unrecognized jsonpath item type: %d", type);
 			return NULL;
@@ -1183,6 +1200,7 @@ jspInitByBuffer(JsonPathItem *v, char *base, int32 pos)
 		case jpiStrTranslate:
 		case jpiStrSplit:
 		case jpiStrSplitPart:
+		case jpiStrJoin:
 			read_int32(v->content.args.left, base, pos);
 			read_int32(v->content.args.right, base, pos);
 			break;
@@ -1310,6 +1328,7 @@ jspGetNext(JsonPathItem *v, JsonPathItem *a)
 			   v->type == jpiStrInitcap ||
 			   v->type == jpiStrSplitPart ||
 			   v->type == jpiStrSplit ||
+			   v->type == jpiStrJoin ||
 			   v->type == jpiStrTranslate);
 
 		if (a)
@@ -1341,6 +1360,7 @@ jspGetLeftArg(JsonPathItem *v, JsonPathItem *a)
 		   v->type == jpiStrReplace ||
 		   v->type == jpiStrTranslate ||
 		   v->type == jpiStrSplit ||
+		   v->type == jpiStrJoin ||
 		   v->type == jpiStrSplitPart);
 
 	jspInitByBuffer(a, v->base, v->content.args.left);
@@ -1367,6 +1387,7 @@ jspGetRightArg(JsonPathItem *v, JsonPathItem *a)
 		   v->type == jpiStrReplace ||
 		   v->type == jpiStrTranslate ||
 		   v->type == jpiStrSplitPart ||
+		   v->type == jpiStrJoin ||
 		   v->type == jpiStrSplit);
 
 	jspInitByBuffer(a, v->base, v->content.args.right);
@@ -1677,6 +1698,7 @@ jspIsMutableWalker(JsonPathItem *jpi, struct JsonPathMutableContext *cxt)
 			case jpiStrSplitPart:
 			case jpiStrSplit:
 			case jpiStrTranslate:
+			case jpiStrJoin:
 				status = jpdsNonDateTime;
 				break;
 
diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index 93f31b40b0b..cb8bb1aac25 100644
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -1699,6 +1699,117 @@ executeItemOptUnwrapTarget(JsonPathExecContext *cxt, JsonPathItem *jsp,
 				return executeStringInternalMethod(cxt, jsp, jb, found);
 			}
 			break;
+		case jpiStrJoin:
+			{
+				JsonPathItem next_elem;
+				JsonbValue	jbv_res;
+				char	   *sep;
+				char	   *null_replace = NULL;
+				StringInfoData buf;
+				bool		first = true;
+				bool		hasNext;
+
+				jspGetLeftArg(jsp, &elem);
+				sep = jspGetString(&elem, NULL);
+
+				if (jsp->content.args.right != 0)
+				{
+					jspGetRightArg(jsp, &elem);
+					null_replace = jspGetString(&elem, NULL);
+				}
+
+				/* Validate target is an array */
+				if (JsonbType(jb) != jbvArray)
+				{
+					RETURN_ERROR(ereport(ERROR,
+										 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+										  errmsg("jsonpath item method .join() can only be applied to an array"))));
+				}
+
+				initStringInfo(&buf);
+
+				/* Process the array elements */
+				if (jb->type == jbvBinary)
+				{
+					/* Serialized Binary Blob */
+					JsonbIterator *it;
+					JsonbValue	v;
+					JsonbIteratorToken tok;
+
+					it = JsonbIteratorInit(jb->val.binary.data);
+					while ((tok = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
+					{
+						if (tok != WJB_ELEM)
+							continue;
+
+						if (v.type == jbvString)
+						{
+							if (!first)
+								appendStringInfoString(&buf, sep);
+							appendBinaryStringInfo(&buf, v.val.string.val, v.val.string.len);
+							first = false;
+						}
+						else if (v.type == jbvNull)
+						{
+							if (null_replace)
+							{
+								if (!first)
+									appendStringInfoString(&buf, sep);
+								appendStringInfoString(&buf, null_replace);
+								first = false;
+							}
+						}
+						else
+						{
+							RETURN_ERROR(ereport(ERROR,
+												 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+												  errmsg("jsonpath .join() array elements must be strings or nulls"))));
+						}
+					}
+				}
+				else
+				{
+					/* Recursive Tree (jbvArray) */
+					for (int i = 0; i < jb->val.array.nElems; i++)
+					{
+						JsonbValue *v = &jb->val.array.elems[i];
+
+						if (v->type == jbvString)
+						{
+							if (!first)
+								appendStringInfoString(&buf, sep);
+							appendBinaryStringInfo(&buf, v->val.string.val, v->val.string.len);
+							first = false;
+						}
+						else if (v->type == jbvNull)
+						{
+							if (null_replace)
+							{
+								if (!first)
+									appendStringInfoString(&buf, sep);
+								appendStringInfoString(&buf, null_replace);
+								first = false;
+							}
+						}
+						else
+						{
+							RETURN_ERROR(ereport(ERROR,
+												 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+												  errmsg("jsonpath .join() array elements must be strings or nulls"))));
+						}
+					}
+				}
+
+				jbv_res.type = jbvString;
+				jbv_res.val.string.val = buf.data;
+				jbv_res.val.string.len = buf.len;
+
+				hasNext = jspGetNext(jsp, &next_elem);
+				if (!hasNext && !found)
+					return jperOk;
+
+				return executeNextItem(cxt, jsp, hasNext ? &next_elem : NULL, &jbv_res, found);
+			}
 
 		default:
 			elog(ERROR, "unrecognized jsonpath item type: %d", jsp->type);
diff --git a/src/backend/utils/adt/jsonpath_gram.y b/src/backend/utils/adt/jsonpath_gram.y
index fe30e8a6147..eb2b952e311 100644
--- a/src/backend/utils/adt/jsonpath_gram.y
+++ b/src/backend/utils/adt/jsonpath_gram.y
@@ -87,7 +87,7 @@ static bool makeItemLikeRegex(JsonPathParseItem *expr,
 %token	<str>		BIGINT_P BOOLEAN_P DATE_P DECIMAL_P INTEGER_P NUMBER_P
 %token	<str>		STRINGFUNC_P TIME_P TIME_TZ_P TIMESTAMP_P TIMESTAMP_TZ_P
 %token	<str>		STR_REPLACE_P STR_LOWER_P STR_UPPER_P STR_LTRIM_P STR_RTRIM_P STR_BTRIM_P
-					STR_INITCAP_P STR_SPLIT_P STR_SPLIT_PART_P STR_TRANSLATE_P
+					STR_INITCAP_P STR_SPLIT_P STR_SPLIT_PART_P STR_TRANSLATE_P STR_JOIN_P
 
 %type	<result>	result
 
@@ -290,6 +290,10 @@ accessor_op:
 		{ $$ = makeItemBinary(jpiStrSplit, $4, NULL); }
 	| '.' STR_SPLIT_P '(' str_str_args ')'
 		{ $$ = makeItemBinary(jpiStrSplit, linitial($4), lsecond($4)); }
+	| '.' STR_JOIN_P '(' str_elem ')'
+		{ $$ = makeItemBinary(jpiStrJoin, $4, NULL); }
+	| '.' STR_JOIN_P '(' str_str_args ')'
+		{ $$ = makeItemBinary(jpiStrJoin, linitial($4), lsecond($4)); }
 	| '.' STR_LTRIM_P '(' opt_str_arg ')'
 		{ $$ = makeItemUnary(jpiStrLtrim, $4); }
 	| '.' STR_RTRIM_P '(' opt_str_arg ')'
@@ -393,6 +397,7 @@ key_name:
 	| STR_LTRIM_P
 	| STR_RTRIM_P
 	| STR_BTRIM_P
+	| STR_JOIN_P
 	;
 
 method:
diff --git a/src/backend/utils/adt/jsonpath_scan.l b/src/backend/utils/adt/jsonpath_scan.l
index b06d0abb64a..bd49941a8fc 100644
--- a/src/backend/utils/adt/jsonpath_scan.l
+++ b/src/backend/utils/adt/jsonpath_scan.l
@@ -406,6 +406,7 @@ static const JsonPathKeyword keywords[] = {
 	{3, false, LAX_P, "lax"},
 	{4, false, DATE_P, "date"},
 	{4, false, FLAG_P, "flag"},
+	{4, false, STR_JOIN_P, "join"},
 	{4, false, LAST_P, "last"},
 	{4, true, NULL_P, "null"},
 	{4, false, SIZE_P, "size"},
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h
index c1c7812a36a..f61639e3767 100644
--- a/src/include/utils/jsonpath.h
+++ b/src/include/utils/jsonpath.h
@@ -115,6 +115,7 @@ typedef enum JsonPathItemType
 	jpiTimeTz,					/* .time_tz() item method */
 	jpiTimestamp,				/* .timestamp() item method */
 	jpiTimestampTz,				/* .timestamp_tz() item method */
+	jpiStrJoin,					/* .join() item method */
 	jpiStrReplace,				/* .replace() item method */
 	jpiStrLower,				/* .lower() item method */
 	jpiStrUpper,				/* .upper() item method */
diff --git a/src/test/regress/expected/jsonb_jsonpath.out b/src/test/regress/expected/jsonb_jsonpath.out
index 8fc530201a6..7e247ba7505 100644
--- a/src/test/regress/expected/jsonb_jsonpath.out
+++ b/src/test/regress/expected/jsonb_jsonpath.out
@@ -3135,6 +3135,80 @@ select jsonb_path_query('"a,b,c"', '$.split(",")[1]');
  "b"
 (1 row)
 
+-- Test .join() method
+select jsonb_path_query('["a", "b", "c"]', '$.join("-")');
+ jsonb_path_query 
+------------------
+ "a-b-c"
+(1 row)
+
+-- Join with null replacement
+select jsonb_path_query('["a", "b", "c"]', '$.join("-", "N/A")');
+ jsonb_path_query 
+------------------
+ "a-b-c"
+(1 row)
+
+-- Null handling: default (skip)
+select jsonb_path_query('["a", null, "c"]', '$.join("-")');
+ jsonb_path_query 
+------------------
+ "a-c"
+(1 row)
+
+-- Null handling: replacement
+select jsonb_path_query('["a", null, "c"]', '$.join("-", "N/A")');
+ jsonb_path_query 
+------------------
+ "a-N/A-c"
+(1 row)
+
+-- Empty array (should return empty string)
+select jsonb_path_query('[]', '$.join("-")');
+ jsonb_path_query 
+------------------
+ ""
+(1 row)
+
+-- Pipeline integration: .join().upper()
+select jsonb_path_query('["hello", "world"]', '$.join(" ").upper()');
+ jsonb_path_query 
+------------------
+ "HELLO WORLD"
+(1 row)
+
+-- Pipeline integration: .split().join()
+select jsonb_path_query('"a,b,c"', '$.split(",").join("|")');
+ jsonb_path_query 
+------------------
+ "a|b|c"
+(1 row)
+
+-- Error case: Non-string element (should trigger our ereport)
+select jsonb_path_query('[1, "a"]', '$.join("-")');
+ERROR:  jsonpath .join() array elements must be strings or nulls
+-- Error case: Nested object
+select jsonb_path_query('["a", {"b": 1}]', '$.join("-")');
+ERROR:  jsonpath .join() array elements must be strings or nulls
+-- Error case: Applied to a scalar
+select jsonb_path_query('"not an array"', '$.join("-")');
+ERROR:  jsonpath item method .join() can only be applied to an array
+-- Lax mode: should still error under current conservative implementation
+select jsonb_path_query('[1, "a"]', 'lax $.join("-")');
+ERROR:  jsonpath .join() array elements must be strings or nulls
+select jsonb_path_query('"not an array"', 'lax $.join("-")');
+ERROR:  jsonpath item method .join() can only be applied to an array
+-- Silent mode: should suppress errors and return no rows
+select jsonb_path_query('[1, "a"]', '$.join("-")', silent => true);
+ jsonb_path_query 
+------------------
+(0 rows)
+
+select jsonb_path_query('"not an array"', '$.join("-")', silent => true);
+ jsonb_path_query 
+------------------
+(0 rows)
+
 -- Test string methods play nicely together
 select jsonb_path_query('"hello world"', '$.replace("hello","bye").upper()');
  jsonb_path_query 
@@ -3166,6 +3240,12 @@ select jsonb_path_query('"   hElLo WorlD "', '$.btrim().lower().upper().lower().
  true
 (1 row)
 
+select jsonb_path_query('"  A,b,C  "', '$.btrim().lower().split(",").join("-").replace("a","x").upper() starts with "X-B"');
+ jsonb_path_query 
+------------------
+ true
+(1 row)
+
 -- Test .time()
 select jsonb_path_query('null', '$.time()');
 ERROR:  jsonpath item method .time() can only be applied to a string
diff --git a/src/test/regress/expected/jsonpath.out b/src/test/regress/expected/jsonpath.out
index a9ef9cefced..6b64603a0bf 100644
--- a/src/test/regress/expected/jsonpath.out
+++ b/src/test/regress/expected/jsonpath.out
@@ -519,6 +519,18 @@ select '$.split(",")'::jsonpath;
  $.split(",")
 (1 row)
 
+select '$.join(",")'::jsonpath;
+  jsonpath   
+-------------
+ $.join(",")
+(1 row)
+
+select '$.join(",", "N/A")'::jsonpath;
+      jsonpath      
+--------------------
+ $.join(",", "N/A")
+(1 row)
+
 -- Parse errors
 select '$.replace("hello")'::jsonpath;
 ERROR:  syntax error at or near ")" of jsonpath input
@@ -655,6 +667,26 @@ select '$.btrim'::jsonpath;
  $."btrim"
 (1 row)
 
+select '$.join()'::jsonpath;
+ERROR:  syntax error at or near ")" of jsonpath input
+LINE 1: select '$.join()'::jsonpath;
+               ^
+select '$.join(",", "replacement", "extra")'::jsonpath;
+ERROR:  syntax error at or near "," of jsonpath input
+LINE 1: select '$.join(",", "replacement", "extra")'::jsonpath;
+               ^
+select '$.join(42)'::jsonpath;
+ERROR:  syntax error at or near "42" of jsonpath input
+LINE 1: select '$.join(42)'::jsonpath;
+               ^
+select '$.join(true)'::jsonpath;
+ERROR:  syntax error at end of jsonpath input
+LINE 1: select '$.join(true)'::jsonpath;
+               ^
+select '$.join("x", 123)'::jsonpath;
+ERROR:  syntax error at or near "123" of jsonpath input
+LINE 1: select '$.join("x", 123)'::jsonpath;
+               ^
 select '$.time()'::jsonpath;
  jsonpath 
 ----------
diff --git a/src/test/regress/expected/sqljson_queryfuncs.out b/src/test/regress/expected/sqljson_queryfuncs.out
index c3fc890a9c4..2df3e34d0e0 100644
--- a/src/test/regress/expected/sqljson_queryfuncs.out
+++ b/src/test/regress/expected/sqljson_queryfuncs.out
@@ -1282,6 +1282,7 @@ CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.replace("hello", "bye")
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.translate("hello", "bye")'));
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.split_part(",", 2)'));
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.split(",")'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.join(",")'));
 -- DEFAULT expression
 CREATE OR REPLACE FUNCTION ret_setint() RETURNS SETOF integer AS
 $$
diff --git a/src/test/regress/sql/jsonb_jsonpath.sql b/src/test/regress/sql/jsonb_jsonpath.sql
index 784fbc577f2..86f7d2fe4b6 100644
--- a/src/test/regress/sql/jsonb_jsonpath.sql
+++ b/src/test/regress/sql/jsonb_jsonpath.sql
@@ -739,12 +739,40 @@ select jsonb_path_query('"a,,c"', '$.split(",", "")');
 -- proving the output is a real, indexable JSON array
 select jsonb_path_query('"a,b,c"', '$.split(",")[1]');
 
+-- Test .join() method
+select jsonb_path_query('["a", "b", "c"]', '$.join("-")');
+-- Join with null replacement
+select jsonb_path_query('["a", "b", "c"]', '$.join("-", "N/A")');
+-- Null handling: default (skip)
+select jsonb_path_query('["a", null, "c"]', '$.join("-")');
+-- Null handling: replacement
+select jsonb_path_query('["a", null, "c"]', '$.join("-", "N/A")');
+-- Empty array (should return empty string)
+select jsonb_path_query('[]', '$.join("-")');
+-- Pipeline integration: .join().upper()
+select jsonb_path_query('["hello", "world"]', '$.join(" ").upper()');
+-- Pipeline integration: .split().join()
+select jsonb_path_query('"a,b,c"', '$.split(",").join("|")');
+-- Error case: Non-string element (should trigger our ereport)
+select jsonb_path_query('[1, "a"]', '$.join("-")');
+-- Error case: Nested object
+select jsonb_path_query('["a", {"b": 1}]', '$.join("-")');
+-- Error case: Applied to a scalar
+select jsonb_path_query('"not an array"', '$.join("-")');
+-- Lax mode: should still error under current conservative implementation
+select jsonb_path_query('[1, "a"]', 'lax $.join("-")');
+select jsonb_path_query('"not an array"', 'lax $.join("-")');
+-- Silent mode: should suppress errors and return no rows
+select jsonb_path_query('[1, "a"]', '$.join("-")', silent => true);
+select jsonb_path_query('"not an array"', '$.join("-")', silent => true);
+
 -- Test string methods play nicely together
 select jsonb_path_query('"hello world"', '$.replace("hello","bye").upper()');
 select jsonb_path_query('"hElLo WorlD"', '$.lower().upper().lower().replace("hello","bye")');
 select jsonb_path_query('"hElLo WorlD"', '$.upper().lower().upper().replace("HELLO", "BYE")');
 select jsonb_path_query('"hElLo WorlD"', '$.lower().upper().lower().replace("hello","bye") starts with "bye"');
 select jsonb_path_query('"   hElLo WorlD "', '$.btrim().lower().upper().lower().replace("hello","bye") starts with "bye"');
+select jsonb_path_query('"  A,b,C  "', '$.btrim().lower().split(",").join("-").replace("a","x").upper() starts with "X-B"');
 
 -- Test .time()
 select jsonb_path_query('null', '$.time()');
diff --git a/src/test/regress/sql/jsonpath.sql b/src/test/regress/sql/jsonpath.sql
index ef27c8e7bb6..c524dc7a3d4 100644
--- a/src/test/regress/sql/jsonpath.sql
+++ b/src/test/regress/sql/jsonpath.sql
@@ -92,6 +92,8 @@ select '$.btrim("xyz")'::jsonpath;
 select '$.initcap()'::jsonpath;
 select '$.split_part("~@~", 2)'::jsonpath;
 select '$.split(",")'::jsonpath;
+select '$.join(",")'::jsonpath;
+select '$.join(",", "N/A")'::jsonpath;
 
 -- Parse errors
 select '$.replace("hello")'::jsonpath;
@@ -125,6 +127,11 @@ select '$.split'::jsonpath;
 select '$.ltrim'::jsonpath;
 select '$.rtrim'::jsonpath;
 select '$.btrim'::jsonpath;
+select '$.join()'::jsonpath;
+select '$.join(",", "replacement", "extra")'::jsonpath;
+select '$.join(42)'::jsonpath;
+select '$.join(true)'::jsonpath;
+select '$.join("x", 123)'::jsonpath;
 
 select '$.time()'::jsonpath;
 select '$.time(6)'::jsonpath;
diff --git a/src/test/regress/sql/sqljson_queryfuncs.sql b/src/test/regress/sql/sqljson_queryfuncs.sql
index 83ddfc8bc83..ba9d7b7ee47 100644
--- a/src/test/regress/sql/sqljson_queryfuncs.sql
+++ b/src/test/regress/sql/sqljson_queryfuncs.sql
@@ -412,6 +412,7 @@ CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.replace("hello", "bye")
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.translate("hello", "bye")'));
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.split_part(",", 2)'));
 CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.split(",")'));
+CREATE INDEX ON test_jsonb_mutability (JSON_QUERY(js, '$.join(",")'));
 
 -- DEFAULT expression
 CREATE OR REPLACE FUNCTION ret_setint() RETURNS SETOF integer AS
-- 
2.53.0