-- maxLength validation
-- shorter is valid
SELECT is_jsonb_valid('{"maxLength":2}', '"f"');
 is_jsonb_valid 
----------------
 t
(1 row)

-- exact length is valid
SELECT is_jsonb_valid('{"maxLength":2}', '"fo"');
 is_jsonb_valid 
----------------
 t
(1 row)

-- too long is invalid
SELECT is_jsonb_valid('{"maxLength":2}', '"foo"');
 is_jsonb_valid 
----------------
 f
(1 row)

-- ignores non-strings
SELECT is_jsonb_valid('{"maxLength":2}', '100');
 is_jsonb_valid 
----------------
 t
(1 row)

-- two supplementary Unicode code points is long enough
SELECT is_jsonb_valid('{"maxLength":2}', '"💩💩"');
 is_jsonb_valid 
----------------
 t
(1 row)