"""Authored review example, not a real assistant transcript."""
import re

def proposed(value):
    return isinstance(value,str) and re.match(r'^CUST-\d{4}-\d{4}',value) is not None

def corrected(value):
    return isinstance(value,str) and re.fullmatch(r'(?:[A-Z]{2}-[0-9]{4}|CUST-[0-9]{4}-[0-9]{4})',value) is not None

CASES=[
 ('legacy','AB-1234',True),
 ('current','CUST-2025-0007',True),
 ('trailing text','CUST-2025-0007extra',False),
 ('Unicode digits','CUST-٢٠٢٥-٠٠٠٧',False),
 ('empty','',False),
 ('lowercase','cust-2025-0007',False),
 ('leading text','xCUST-2025-0007',False),
 ('trailing newline','CUST-2025-0007\n',False),
]
if __name__=='__main__':
    self_cases=[('CUST-2025-0007',True),('',False)]
    assert all(proposed(v)==want for v,want in self_cases)
    proposed_correct=0
    for label,value,want in CASES:
        a=proposed(value);b=corrected(value)
        assert b==want,(label,b,want)
        proposed_correct+=a==want
        print(label,repr(value),'expected',want,'proposed',a,'corrected',b)
    assert proposed_correct==4
    print('10/10 assertions passed. Proposed matches4/8 independent cases despite passing2/2 narrow self-cases.')