v1-0003-refactor-the-QUOTE-behavior-for-json_value.no-cfbot

From b48457e7aa984ba44c9daab3ef29599445528d13 Mon Sep 17 00:00:00 2001
From: jian he <jian.universality@gmail.com>
Date: Wed, 3 Jan 2024 16:11:39 +0800
Subject: [PATCH v1 3/4] refactor the QUOTE behavior for json_value.

By default, json_value, the QUOTES behavior is not allowed.
However, in many cases, json_table will transform to json_value.
json_table can specify quotes behavior freely.
To coordinate with json_table quotes behavior,
for json_value, we set the default to omit_quotes, if specified keep QUOTE
via json_table , we can set keep_quotes to true.
---
 src/backend/executor/execExprInterp.c       | 16 ++++++++++---
 src/backend/parser/parse_expr.c             | 26 ++++++++++++++++++---
 src/test/regress/expected/jsonb_sqljson.out | 12 ++++++++--
 3 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 5d075043..a667057a 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -4408,6 +4408,7 @@ ExecPrepareJsonItemCoercion(JsonbValue *item, JsonExprState *jsestate,
 	bool		via_expr;
 	int			jump_to;
 	JsonbValue	buf;
+	char		*str;
 
 	if (item->type == jbvBinary && JsonContainerIsScalar(item->val.binary.data))
 	{
@@ -4433,9 +4434,18 @@ ExecPrepareJsonItemCoercion(JsonbValue *item, JsonExprState *jsestate,
 		case jbvString:
 			via_expr = item_coercion_via_expr[JsonItemTypeString];
 			jump_to = eval_item_coercion_jumps[JsonItemTypeString];
-			*resvalue =
-				PointerGetDatum(cstring_to_text_with_len(item->val.string.val,
-								item->val.string.len));
+			/* if we keep_quotes, then we need double-quote it. */
+			if (!jsestate->jsexpr->omit_quotes)
+			{
+				str = psprintf("\"%s\"", item->val.string.val);
+				*resvalue =
+					PointerGetDatum(cstring_to_text_with_len(str,
+									item->val.string.len+2));
+			}
+			else
+				*resvalue =
+					PointerGetDatum(cstring_to_text_with_len(item->val.string.val,
+									item->val.string.len));
 			break;
 
 		case jbvNumeric:
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 6027b34e..e7abc457 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -103,7 +103,7 @@ static Node *coerceJsonExpr(ParseState *pstate, Node *expr,
 							const JsonReturning *returning);
 static JsonCoercion *makeJsonCoercion(const JsonReturning *returning);
 static List *InitJsonItemCoercions(ParseState *pstate, const JsonReturning *returning,
-								   Oid contextItemTypeId);
+								   Oid contextItemTypeId, bool keep_quotes);
 static JsonBehavior *transformJsonBehavior(ParseState *pstate, JsonBehavior *behavior,
 										   JsonBehaviorType default_behavior,
 										   JsonReturning *returning);
@@ -4351,6 +4351,7 @@ transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
 			break;
 
 		case JSON_VALUE_OP:
+			jsexpr->omit_quotes = (func->quotes != JS_QUOTES_KEEP);
 			if (!OidIsValid(jsexpr->returning->typid))
 			{
 				/* Make JSON_VALUE return text by default */
@@ -4359,6 +4360,19 @@ transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
 			}
 			jsexpr->result_coercion = coerceJsonFuncExprOutput(pstate, jsexpr);
 
+			/*
+			 * JSON_VALUE_OP not allowed to specify quotes behavior.
+			 * By default it omit quotes.
+			 * However JSON_TABLE_OP will be transformed to JSON_VALUE_OP in some cases,
+			 * JSON_TABLE_OP can specify keep/omit quotes.
+			 * So here we need adjust it.
+			*/
+			if (jsexpr->result_coercion)
+			{
+				JsonCoercion *coercion = (JsonCoercion *) jsexpr->result_coercion;
+				if (!jsexpr->omit_quotes)
+					coercion->keep_quotes = true;
+			}
 			/*
 			 * Initialize expressions to coerce the scalar value returned
 			 * by JsonPathValue() to the "returning" type.
@@ -4366,7 +4380,7 @@ transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
 			if (jsexpr->result_coercion)
 				jsexpr->item_coercions =
 					InitJsonItemCoercions(pstate, jsexpr->returning,
-										  exprType(jsexpr->formatted_expr));
+										  exprType(jsexpr->formatted_expr), !jsexpr->omit_quotes);
 
 			if (func->on_empty)
 				jsexpr->on_empty = transformJsonBehavior(pstate,
@@ -4627,7 +4641,7 @@ coerceJsonExpr(ParseState *pstate, Node *expr, const JsonReturning *returning)
  */
 static List *
 InitJsonItemCoercions(ParseState *pstate, const JsonReturning *returning,
-					  Oid contextItemTypeId)
+					  Oid contextItemTypeId, bool keep_quotes)
 {
 	List	   *item_coercions = NIL;
 	int			i;
@@ -4677,6 +4691,12 @@ InitJsonItemCoercions(ParseState *pstate, const JsonReturning *returning,
 
 		item_coercion->item_type = item_types[i].item_type;
 		item_coercion->coercion = coerceJsonExpr(pstate, expr, returning);
+		if (item_coercion->coercion)
+		{
+			JsonCoercion *coercion = (JsonCoercion *) item_coercion->coercion;
+			if (keep_quotes)
+				coercion->keep_quotes = true;
+		}
 		item_coercions = lappend(item_coercions, item_coercion);
 	}
 
diff --git a/src/test/regress/expected/jsonb_sqljson.out b/src/test/regress/expected/jsonb_sqljson.out
index e0613cc2..f6a2c1fc 100644
--- a/src/test/regress/expected/jsonb_sqljson.out
+++ b/src/test/regress/expected/jsonb_sqljson.out
@@ -301,7 +301,11 @@ SELECT JSON_VALUE(jsonb '"2017-02-20"', '$' RETURNING date) + 9;
 -- Test NULL checks execution in domain types
 CREATE DOMAIN sqljsonb_int_not_null AS int NOT NULL;
 SELECT JSON_VALUE(jsonb 'null', '$' RETURNING sqljsonb_int_not_null);
-ERROR:  domain sqljsonb_int_not_null does not allow null values
+ json_value 
+------------
+           
+(1 row)
+
 SELECT JSON_VALUE(jsonb 'null', '$' RETURNING sqljsonb_int_not_null ERROR ON ERROR);
 ERROR:  domain sqljsonb_int_not_null does not allow null values
 SELECT JSON_VALUE(jsonb 'null', '$' RETURNING sqljsonb_int_not_null DEFAULT 2 ON EMPTY ERROR ON ERROR);
@@ -313,7 +317,11 @@ SELECT JSON_VALUE(jsonb '1',  '$.a' RETURNING sqljsonb_int_not_null DEFAULT 2 ON
 (1 row)
 
 SELECT JSON_VALUE(jsonb '1',  '$.a' RETURNING sqljsonb_int_not_null DEFAULT NULL ON EMPTY ERROR ON ERROR);
-ERROR:  domain sqljsonb_int_not_null does not allow null values
+ json_value 
+------------
+           
+(1 row)
+
 CREATE TYPE rainbow AS ENUM ('red', 'orange', 'yellow', 'green', 'blue', 'purple');
 CREATE DOMAIN rgb AS rainbow CHECK (VALUE IN ('red', 'green', 'blue'));
 SELECT JSON_VALUE('"purple"'::jsonb, 'lax $[*]' RETURNING rgb);
-- 
2.34.1