-- pattern validation
-- a matching pattern is valid
SELECT is_jsonb_valid('{"pattern":"^a*$"}', '"aaa"');
 is_jsonb_valid 
----------------
 t
(1 row)

-- a non-matching pattern is invalid
SELECT is_jsonb_valid('{"pattern":"^a*$"}', '"abc"');
 is_jsonb_valid 
----------------
 f
(1 row)

-- ignores non-strings
SELECT is_jsonb_valid('{"pattern":"^a*$"}', 'true');
 is_jsonb_valid 
----------------
 t
(1 row)

-- pattern is not anchored
-- matches a substring
SELECT is_jsonb_valid('{"pattern":"a+"}', '"xxaayy"');
 is_jsonb_valid 
----------------
 t
(1 row)