-- minItems validation
-- longer is valid
SELECT is_jsonb_valid('{"minItems":1}', '[1,2]');
 is_jsonb_valid 
----------------
 t
(1 row)

-- exact length is valid
SELECT is_jsonb_valid('{"minItems":1}', '[1]');
 is_jsonb_valid 
----------------
 t
(1 row)

-- too short is invalid
SELECT is_jsonb_valid('{"minItems":1}', '[]');
 is_jsonb_valid 
----------------
 f
(1 row)

-- ignores non-arrays
SELECT is_jsonb_valid('{"minItems":1}', '""');
 is_jsonb_valid 
----------------
 t
(1 row)