Improve error reporting for jsonpath .double() method

When jsonpath .double() method detects that numeric or string can't be
converted to double precision, it throws an error.  This commit makes these
errors explicitly express the reason of failure.

Discussion: https://postgr.es/m/CAPpHfdtqJtiSXkP7tOXez18NxhLUH_-75bL8%3DOce4Ki%2Bbv7V6Q%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Tom Lane
Backpatch-through: 12

3 files changed, 8 insertions, 5 deletions

diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index 135025cf57..25ec3dcd80 100644
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -1055,7 +1055,7 @@ executeItemOptUnwrapTarget(JsonPathExecContext *cxt, JsonPathItem *jsp,
 					if (have_error)
 						RETURN_ERROR(ereport(ERROR,
 											 (errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
-											  errmsg("jsonpath item method .%s() can only be applied to a numeric value",
+											  errmsg("numeric argument of jsonpath item method .%s() is out of range for type double precision",
 													 jspOperationName(jsp->type)))));
 					res = jperOk;
 				}
@@ -1076,7 +1076,7 @@ executeItemOptUnwrapTarget(JsonPathExecContext *cxt, JsonPathItem *jsp,
 					if (have_error || isinf(val))
 						RETURN_ERROR(ereport(ERROR,
 											 (errcode(ERRCODE_NON_NUMERIC_SQL_JSON_ITEM),
-											  errmsg("jsonpath item method .%s() can only be applied to a numeric value",
+											  errmsg("string argument of jsonpath item method .%s() is not a valid representation of a double precision number",
 													 jspOperationName(jsp->type)))));
 
 					jb = &jbv;
diff --git a/src/test/regress/expected/jsonb_jsonpath.out b/src/test/regress/expected/jsonb_jsonpath.out
index 83a050d3e2..f8a5deb2b9 100644
--- a/src/test/regress/expected/jsonb_jsonpath.out
+++ b/src/test/regress/expected/jsonb_jsonpath.out
@@ -1496,7 +1496,9 @@ select jsonb_path_query('"1.23"', '$.double()');
 (1 row)
 
 select jsonb_path_query('"1.23aaa"', '$.double()');
-ERROR:  jsonpath item method .double() can only be applied to a numeric value
+ERROR:  string argument of jsonpath item method .double() is not a valid representation of a double precision number
+select jsonb_path_query('1e1000', '$.double()');
+ERROR:  numeric argument of jsonpath item method .double() is out of range for type double precision
 select jsonb_path_query('"nan"', '$.double()');
  jsonb_path_query 
 ------------------
@@ -1510,9 +1512,9 @@ select jsonb_path_query('"NaN"', '$.double()');
 (1 row)
 
 select jsonb_path_query('"inf"', '$.double()');
-ERROR:  jsonpath item method .double() can only be applied to a numeric value
+ERROR:  string argument of jsonpath item method .double() is not a valid representation of a double precision number
 select jsonb_path_query('"-inf"', '$.double()');
-ERROR:  jsonpath item method .double() can only be applied to a numeric value
+ERROR:  string argument of jsonpath item method .double() is not a valid representation of a double precision number
 select jsonb_path_query('"inf"', '$.double()', silent => true);
  jsonb_path_query 
 ------------------
diff --git a/src/test/regress/sql/jsonb_jsonpath.sql b/src/test/regress/sql/jsonb_jsonpath.sql
index 731b4d444c..a50abed95d 100644
--- a/src/test/regress/sql/jsonb_jsonpath.sql
+++ b/src/test/regress/sql/jsonb_jsonpath.sql
@@ -312,6 +312,7 @@ select jsonb_path_query('{}', '$.double()', silent => true);
 select jsonb_path_query('1.23', '$.double()');
 select jsonb_path_query('"1.23"', '$.double()');
 select jsonb_path_query('"1.23aaa"', '$.double()');
+select jsonb_path_query('1e1000', '$.double()');
 select jsonb_path_query('"nan"', '$.double()');
 select jsonb_path_query('"NaN"', '$.double()');
 select jsonb_path_query('"inf"', '$.double()');