Convert json_in and jsonb_in to report errors softly.

This requires a bit of further infrastructure-extension to allow
trapping errors reported by numeric_in and pg_unicode_to_server,
but otherwise it's pretty straightforward.

In the case of jsonb_in, we are only capturing errors reported
during the initial "parse" phase.  The value-construction phase
(JsonbValueToJsonb) can also throw errors if assorted implementation
limits are exceeded.  We should improve that, but it seems like a
separable project.

Andrew Dunstan and Tom Lane

Discussion: https://postgr.es/m/3bac9841-fe07-713d-fa42-606c225567d6@dunslane.net

7 files changed, 91 insertions, 6 deletions

diff --git a/src/test/regress/expected/json.out b/src/test/regress/expected/json.out
index cb181226e9..af96ce4180 100644
--- a/src/test/regress/expected/json.out
+++ b/src/test/regress/expected/json.out
@@ -320,6 +320,25 @@ LINE 1: SELECT '{
 DETAIL:  Expected JSON value, but found "}".
 CONTEXT:  JSON data, line 4: ...yveryveryveryveryveryveryveryverylongfieldname":}
 -- ERROR missing value for last field
+-- test non-error-throwing input
+select pg_input_is_valid('{"a":true}', 'json');
+ pg_input_is_valid 
+-------------------
+ t
+(1 row)
+
+select pg_input_is_valid('{"a":true', 'json');
+ pg_input_is_valid 
+-------------------
+ f
+(1 row)
+
+select pg_input_error_message('{"a":true', 'json');
+       pg_input_error_message       
+------------------------------------
+ invalid input syntax for type json
+(1 row)
+
 --constructors
 -- array_to_json
 SELECT array_to_json(array(select 1 as a));
diff --git a/src/test/regress/expected/json_encoding.out b/src/test/regress/expected/json_encoding.out
index f343f74fe1..083621fb21 100644
--- a/src/test/regress/expected/json_encoding.out
+++ b/src/test/regress/expected/json_encoding.out
@@ -260,3 +260,10 @@ SELECT jsonb '{ "a":  "null \\u0000 escape" }' ->> 'a' as not_an_escape;
  null \u0000 escape
 (1 row)
 
+-- soft error for input-time failure
+select pg_input_error_message('{ "a":  "\ud83d\ude04\ud83d\udc36" }', 'jsonb');
+ pg_input_error_message 
+------------------------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/json_encoding_1.out b/src/test/regress/expected/json_encoding_1.out
index e2fc131b0f..021d226f8d 100644
--- a/src/test/regress/expected/json_encoding_1.out
+++ b/src/test/regress/expected/json_encoding_1.out
@@ -48,7 +48,9 @@ SELECT '"\uaBcD"'::json;		-- OK, uppercase and lower case both OK
 
 -- handling of unicode surrogate pairs
 select json '{ "a":  "\ud83d\ude04\ud83d\udc36" }' -> 'a' as correct_in_utf8;
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: { "a":...
 select json '{ "a":  "\ud83d\ud83d" }' -> 'a'; -- 2 high surrogates in a row
 ERROR:  invalid input syntax for type json
 DETAIL:  Unicode high surrogate must not follow a high surrogate.
@@ -97,7 +99,9 @@ select json '{ "a":  "null \\u0000 escape" }' as not_an_escape;
 (1 row)
 
 select json '{ "a":  "the Copyright \u00a9 sign" }' ->> 'a' as correct_in_utf8;
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: { "a":...
 select json '{ "a":  "dollar \u0024 character" }' ->> 'a' as correct_everywhere;
  correct_everywhere 
 --------------------
@@ -155,14 +159,18 @@ CONTEXT:  JSON data, line 1: ...
 -- use octet_length here so we don't get an odd unicode char in the
 -- output
 SELECT octet_length('"\uaBcD"'::jsonb::text); -- OK, uppercase and lower case both OK
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
 LINE 1: SELECT octet_length('"\uaBcD"'::jsonb::text);
                             ^
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: ...
 -- handling of unicode surrogate pairs
 SELECT octet_length((jsonb '{ "a":  "\ud83d\ude04\ud83d\udc36" }' -> 'a')::text) AS correct_in_utf8;
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
 LINE 1: SELECT octet_length((jsonb '{ "a":  "\ud83d\ude04\ud83d\udc3...
                                    ^
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: { "a":...
 SELECT jsonb '{ "a":  "\ud83d\ud83d" }' -> 'a'; -- 2 high surrogates in a row
 ERROR:  invalid input syntax for type json
 LINE 1: SELECT jsonb '{ "a":  "\ud83d\ud83d" }' -> 'a';
@@ -189,9 +197,11 @@ DETAIL:  Unicode low surrogate must follow a high surrogate.
 CONTEXT:  JSON data, line 1: { "a":...
 -- handling of simple unicode escapes
 SELECT jsonb '{ "a":  "the Copyright \u00a9 sign" }' as correct_in_utf8;
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
 LINE 1: SELECT jsonb '{ "a":  "the Copyright \u00a9 sign" }' as corr...
                      ^
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: { "a":...
 SELECT jsonb '{ "a":  "dollar \u0024 character" }' as correct_everywhere;
      correct_everywhere      
 -----------------------------
@@ -217,9 +227,11 @@ SELECT jsonb '{ "a":  "null \\u0000 escape" }' as not_an_escape;
 (1 row)
 
 SELECT jsonb '{ "a":  "the Copyright \u00a9 sign" }' ->> 'a' as correct_in_utf8;
-ERROR:  conversion between UTF8 and SQL_ASCII is not supported
+ERROR:  unsupported Unicode escape sequence
 LINE 1: SELECT jsonb '{ "a":  "the Copyright \u00a9 sign" }' ->> 'a'...
                      ^
+DETAIL:  Unicode escape value could not be translated to the server's encoding SQL_ASCII.
+CONTEXT:  JSON data, line 1: { "a":...
 SELECT jsonb '{ "a":  "dollar \u0024 character" }' ->> 'a' as correct_everywhere;
  correct_everywhere 
 --------------------
@@ -244,3 +256,10 @@ SELECT jsonb '{ "a":  "null \\u0000 escape" }' ->> 'a' as not_an_escape;
  null \u0000 escape
 (1 row)
 
+-- soft error for input-time failure
+select pg_input_error_message('{ "a":  "\ud83d\ude04\ud83d\udc36" }', 'jsonb');
+       pg_input_error_message        
+-------------------------------------
+ unsupported Unicode escape sequence
+(1 row)
+
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index b2b3677482..be85676b5b 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -310,6 +310,31 @@ LINE 1: SELECT '{
 DETAIL:  Expected JSON value, but found "}".
 CONTEXT:  JSON data, line 4: ...yveryveryveryveryveryveryveryverylongfieldname":}
 -- ERROR missing value for last field
+-- test non-error-throwing input
+select pg_input_is_valid('{"a":true}', 'jsonb');
+ pg_input_is_valid 
+-------------------
+ t
+(1 row)
+
+select pg_input_is_valid('{"a":true', 'jsonb');
+ pg_input_is_valid 
+-------------------
+ f
+(1 row)
+
+select pg_input_error_message('{"a":true', 'jsonb');
+       pg_input_error_message       
+------------------------------------
+ invalid input syntax for type json
+(1 row)
+
+select pg_input_error_message('{"a":1e1000000}', 'jsonb');
+     pg_input_error_message     
+--------------------------------
+ value overflows numeric format
+(1 row)
+
 -- make sure jsonb is passed through json generators without being escaped
 SELECT array_to_json(ARRAY [jsonb '{"a":1}', jsonb '{"b":[2,3]}']);
       array_to_json       
diff --git a/src/test/regress/sql/json.sql b/src/test/regress/sql/json.sql
index 589e0cea36..21534ed959 100644
--- a/src/test/regress/sql/json.sql
+++ b/src/test/regress/sql/json.sql
@@ -81,6 +81,11 @@ SELECT '{
 		"averyveryveryveryveryveryveryveryveryverylongfieldname":}'::json;
 -- ERROR missing value for last field
 
+-- test non-error-throwing input
+select pg_input_is_valid('{"a":true}', 'json');
+select pg_input_is_valid('{"a":true', 'json');
+select pg_input_error_message('{"a":true', 'json');
+
 --constructors
 -- array_to_json
 
diff --git a/src/test/regress/sql/json_encoding.sql b/src/test/regress/sql/json_encoding.sql
index d7fac69733..f87b3bd4f3 100644
--- a/src/test/regress/sql/json_encoding.sql
+++ b/src/test/regress/sql/json_encoding.sql
@@ -76,3 +76,7 @@ SELECT jsonb '{ "a":  "dollar \u0024 character" }' ->> 'a' as correct_everywhere
 SELECT jsonb '{ "a":  "dollar \\u0024 character" }' ->> 'a' as not_an_escape;
 SELECT jsonb '{ "a":  "null \u0000 escape" }' ->> 'a' as fails;
 SELECT jsonb '{ "a":  "null \\u0000 escape" }' ->> 'a' as not_an_escape;
+
+-- soft error for input-time failure
+
+select pg_input_error_message('{ "a":  "\ud83d\ude04\ud83d\udc36" }', 'jsonb');
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 8d25966267..bc44ad1518 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -86,6 +86,12 @@ SELECT '{
 		"averyveryveryveryveryveryveryveryveryverylongfieldname":}'::jsonb;
 -- ERROR missing value for last field
 
+-- test non-error-throwing input
+select pg_input_is_valid('{"a":true}', 'jsonb');
+select pg_input_is_valid('{"a":true', 'jsonb');
+select pg_input_error_message('{"a":true', 'jsonb');
+select pg_input_error_message('{"a":1e1000000}', 'jsonb');
+
 -- make sure jsonb is passed through json generators without being escaped
 SELECT array_to_json(ARRAY [jsonb '{"a":1}', jsonb '{"b":[2,3]}']);