-- Strings.
SELECT '""'::json;				-- OK.
 json 
------
 ""
(1 row)

SELECT $$''$$::json;			-- ERROR, single quotes are not allowed
ERROR:  invalid input syntax for type json
LINE 1: SELECT $$''$$::json;
               ^
DETAIL:  line 1: Token "'" is invalid.
SELECT '"abc"'::json;			-- OK
 json  
-------
 "abc"
(1 row)

SELECT '"abc'::json;			-- ERROR, quotes not closed
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"abc'::json;
               ^
DETAIL:  line 1: Token ""abc" is invalid.
SELECT '"abc
def"'::json;					-- ERROR, unescaped newline in string constant
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"abc
               ^
DETAIL:  line 1: Character "
" must be escaped.
SELECT '"\n\"\\"'::json;		-- OK, legal escapes
   json   
----------
 "\n\"\\"
(1 row)

SELECT '"\v"'::json;			-- ERROR, not a valid JSON escape
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"\v"'::json;
               ^
DETAIL:  line 1: Invalid escape "\v".
SELECT '"\u"'::json;			-- ERROR, incomplete escape
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"\u"'::json;
               ^
DETAIL:  line 1: "\u" must be followed by four hexadecimal digits.
SELECT '"\u00"'::json;			-- ERROR, incomplete escape
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"\u00"'::json;
               ^
DETAIL:  line 1: "\u" must be followed by four hexadecimal digits.
SELECT '"\u000g"'::json;		-- ERROR, g is not a hex digit
ERROR:  invalid input syntax for type json
LINE 1: SELECT '"\u000g"'::json;
               ^
DETAIL:  line 1: "\u" must be followed by four hexadecimal digits.
SELECT '"\u0000"'::json;		-- OK, legal escape
   json   
----------
 "\u0000"
(1 row)

SELECT '"\uaBcD"'::json;		-- OK, uppercase and lower case both OK
   json   
----------
 "\uaBcD"
(1 row)

-- Numbers.
SELECT '1'::json;				-- OK
 json 
------
 1
(1 row)

SELECT '0'::json;				-- OK
 json 
------
 0
(1 row)

SELECT '01'::json;				-- ERROR, not valid according to JSON spec
ERROR:  invalid input syntax for type json
LINE 1: SELECT '01'::json;
               ^
DETAIL:  line 1: Token "01" is invalid.
SELECT '0.1'::json;				-- OK
 json 
------
 0.1
(1 row)

SELECT '9223372036854775808'::json;	-- OK, even though it's too large for int8
        json         
---------------------
 9223372036854775808
(1 row)

SELECT '1e100'::json;			-- OK
 json  
-------
 1e100
(1 row)

SELECT '1.3e100'::json;			-- OK
  json   
---------
 1.3e100
(1 row)

SELECT '1f2'::json;				-- ERROR
ERROR:  invalid input syntax for type json
LINE 1: SELECT '1f2'::json;
               ^
DETAIL:  line 1: Token "1f2" is invalid.
-- Arrays.
SELECT '[]'::json;				-- OK
 json 
------
 []
(1 row)

SELECT '[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]'::json;  -- OK
                                                                                                   json                                                                                                   
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
(1 row)

SELECT '[1,2]'::json;			-- OK
 json  
-------
 [1,2]
(1 row)

SELECT '[1,2,]'::json;			-- ERROR, trailing comma
ERROR:  invalid input syntax for type json: "[1,2,]"
LINE 1: SELECT '[1,2,]'::json;
               ^
DETAIL:  line 1: Expected string, number, object, array, true, false, or null, but found "]".
SELECT '[1,2'::json;			-- ERROR, no closing bracket
ERROR:  invalid input syntax for type json: "[1,2"
LINE 1: SELECT '[1,2'::json;
               ^
DETAIL:  The input string ended unexpectedly.
SELECT '[1,[2]'::json;			-- ERROR, no closing bracket
ERROR:  invalid input syntax for type json: "[1,[2]"
LINE 1: SELECT '[1,[2]'::json;
               ^
DETAIL:  The input string ended unexpectedly.
-- Objects.
SELECT '{}'::json;				-- OK
 json 
------
 {}
(1 row)

SELECT '{"abc"}'::json;			-- ERROR, no value
ERROR:  invalid input syntax for type json: "{"abc"}"
LINE 1: SELECT '{"abc"}'::json;
               ^
DETAIL:  line 1: Expected ":", but found "}".
SELECT '{"abc":1}'::json;		-- OK
   json    
-----------
 {"abc":1}
(1 row)

SELECT '{1:"abc"}'::json;		-- ERROR, keys must be strings
ERROR:  invalid input syntax for type json: "{1:"abc"}"
LINE 1: SELECT '{1:"abc"}'::json;
               ^
DETAIL:  line 1: Expected string or "}", but found "1".
SELECT '{"abc",1}'::json;		-- ERROR, wrong separator
ERROR:  invalid input syntax for type json: "{"abc",1}"
LINE 1: SELECT '{"abc",1}'::json;
               ^
DETAIL:  line 1: Expected ":", but found ",".
SELECT '{"abc"=1}'::json;		-- ERROR, totally wrong separator
ERROR:  invalid input syntax for type json
LINE 1: SELECT '{"abc"=1}'::json;
               ^
DETAIL:  line 1: Token "=" is invalid.
SELECT '{"abc"::1}'::json;		-- ERROR, another wrong separator
ERROR:  invalid input syntax for type json: "{"abc"::1}"
LINE 1: SELECT '{"abc"::1}'::json;
               ^
DETAIL:  line 1: Expected string, number, object, array, true, false, or null, but found ":".
SELECT '{"abc":1,"def":2,"ghi":[3,4],"hij":{"klm":5,"nop":[6]}}'::json; -- OK
                          json                           
---------------------------------------------------------
 {"abc":1,"def":2,"ghi":[3,4],"hij":{"klm":5,"nop":[6]}}
(1 row)

SELECT '{"abc":1:2}'::json;		-- ERROR, colon in wrong spot
ERROR:  invalid input syntax for type json: "{"abc":1:2}"
LINE 1: SELECT '{"abc":1:2}'::json;
               ^
DETAIL:  line 1: Expected "," or "}", but found ":".
SELECT '{"abc":1,3}'::json;		-- ERROR, no value
ERROR:  invalid input syntax for type json: "{"abc":1,3}"
LINE 1: SELECT '{"abc":1,3}'::json;
               ^
DETAIL:  line 1: Expected string, but found "3".
-- Miscellaneous stuff.
SELECT 'true'::json;			-- OK
 json 
------
 true
(1 row)

SELECT 'false'::json;			-- OK
 json  
-------
 false
(1 row)

SELECT 'null'::json;			-- OK
 json 
------
 null
(1 row)

SELECT ' true '::json;			-- OK, even with extra whitespace
  json  
--------
  true 
(1 row)

SELECT 'true false'::json;		-- ERROR, too many values
ERROR:  invalid input syntax for type json: "true false"
LINE 1: SELECT 'true false'::json;
               ^
DETAIL:  line 1: Expected end of input, but found "false".
SELECT 'true, false'::json;		-- ERROR, too many values
ERROR:  invalid input syntax for type json: "true, false"
LINE 1: SELECT 'true, false'::json;
               ^
DETAIL:  line 1: Expected end of input, but found ",".
SELECT 'truf'::json;			-- ERROR, not a keyword
ERROR:  invalid input syntax for type json
LINE 1: SELECT 'truf'::json;
               ^
DETAIL:  line 1: Token "truf" is invalid.
SELECT 'trues'::json;			-- ERROR, not a keyword
ERROR:  invalid input syntax for type json
LINE 1: SELECT 'trues'::json;
               ^
DETAIL:  line 1: Token "trues" is invalid.
SELECT ''::json;				-- ERROR, no value
ERROR:  invalid input syntax for type json: ""
LINE 1: SELECT ''::json;
               ^
DETAIL:  The input string ended unexpectedly.
SELECT '    '::json;			-- ERROR, no value
ERROR:  invalid input syntax for type json: "    "
LINE 1: SELECT '    '::json;
               ^
DETAIL:  The input string ended unexpectedly.
--constructors
-- array_to_json
SELECT array_to_json(array(select 1 as a));
 array_to_json 
---------------
 [1]
(1 row)

SELECT array_to_json(array_agg(q),false) from (select x as b, x * 2 as c from generate_series(1,3) x) q;
                array_to_json                
---------------------------------------------
 [{"b":1,"c":2},{"b":2,"c":4},{"b":3,"c":6}]
(1 row)

SELECT array_to_json(array_agg(q),true) from (select x as b, x * 2 as c from generate_series(1,3) x) q;
  array_to_json  
-----------------
 [{"b":1,"c":2},+
  {"b":2,"c":4},+
  {"b":3,"c":6}]
(1 row)

SELECT array_to_json(array_agg(q),false)
  FROM ( SELECT $$a$$ || x AS b, y AS c, 
               ARRAY[ROW(x.*,ARRAY[1,2,3]),
               ROW(y.*,ARRAY[4,5,6])] AS z 
         FROM generate_series(1,2) x, 
              generate_series(4,5) y) q;
                                                                                                                                 array_to_json                                                                                                                                 
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 [{"b":"a1","c":4,"z":[{"f1":1,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]},{"b":"a1","c":5,"z":[{"f1":1,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]},{"b":"a2","c":4,"z":[{"f1":2,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]},{"b":"a2","c":5,"z":[{"f1":2,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]}]
(1 row)

SELECT array_to_json(array_agg(x),false) from generate_series(5,10) x;
 array_to_json  
----------------
 [5,6,7,8,9,10]
(1 row)

SELECT array_to_json('{{1,5},{99,100}}'::int[]);
  array_to_json   
------------------
 [[1,5],[99,100]]
(1 row)

-- row_to_json
SELECT row_to_json(row(1,'foo'));
     row_to_json     
---------------------
 {"f1":1,"f2":"foo"}
(1 row)

SELECT row_to_json(q) 
FROM (SELECT $$a$$ || x AS b, 
         y AS c, 
         ARRAY[ROW(x.*,ARRAY[1,2,3]),
               ROW(y.*,ARRAY[4,5,6])] AS z 
      FROM generate_series(1,2) x, 
           generate_series(4,5) y) q;
                            row_to_json                             
--------------------------------------------------------------------
 {"b":"a1","c":4,"z":[{"f1":1,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]}
 {"b":"a1","c":5,"z":[{"f1":1,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]}
 {"b":"a2","c":4,"z":[{"f1":2,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]}
 {"b":"a2","c":5,"z":[{"f1":2,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]}
(4 rows)

SELECT row_to_json(q,true) 
FROM (SELECT $$a$$ || x AS b, 
         y AS c, 
         ARRAY[ROW(x.*,ARRAY[1,2,3]),
               ROW(y.*,ARRAY[4,5,6])] AS z 
      FROM generate_series(1,2) x, 
           generate_series(4,5) y) q;
                     row_to_json                     
-----------------------------------------------------
 {"b":"a1",                                         +
  "c":4,                                            +
  "z":[{"f1":1,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]}
 {"b":"a1",                                         +
  "c":5,                                            +
  "z":[{"f1":1,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]}
 {"b":"a2",                                         +
  "c":4,                                            +
  "z":[{"f1":2,"f2":[1,2,3]},{"f1":4,"f2":[4,5,6]}]}
 {"b":"a2",                                         +
  "c":5,                                            +
  "z":[{"f1":2,"f2":[1,2,3]},{"f1":5,"f2":[4,5,6]}]}
(4 rows)

CREATE TEMP TABLE rows AS
SELECT x, 'txt' || x as y
FROM generate_series(1,3) AS x;
SELECT row_to_json(q,true) 
FROM rows q;
 row_to_json  
--------------
 {"x":1,     +
  "y":"txt1"}
 {"x":2,     +
  "y":"txt2"}
 {"x":3,     +
  "y":"txt3"}
(3 rows)

SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),false);
      row_to_json      
-----------------------
 {"f1":[5,6,7,8,9,10]}
(1 row)