{"abstract":"Mistyped codes with a leading 2 are expanded to UPC-A instead of being rejected.","category":"Barcode symbology encoding","checks":8,"contract":"Expand an 8-digit zero-suppressed UPC-E string (number system 0 or 1, six digits d1..d6, check digit passed through) into 12-digit UPC-A: d6 in 0-2 -> d1 d2 d6 0000 d3 d4 d5; d6 = 3 -> d1 d2 d3 00000 d4 d5; d6 = 4 -> d1 d2 d3 d4 00000 d5; d6 in 5-9 -> d1..d5 0000 d6. Invalid input returns None.","evaluation_group":"w2-barcode-symbology-encoding-upce-expansion","failed_approach":"Allowing only 0 rejects valid number system 1 codes.","family":"w2-barcode-symbology-encoding-upce-expansion-number-system","id":"FA-79391","implementations":{"attempt":{"sha256":"ee415e1f63bf374569da38eaf2818f3eee6c3f119d71afdace3fd289114c5a20","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(e):\n    if len(e) != 8 or not all(ch in '0123456789' for ch in e):\n        return None\n    ns, d, chk = e[0], e[1:7], e[7]\n    if ns == '1':\n        return None\n    last = d[5]\n    if last in '012':\n        body = d[0:2] + last + '0000' + d[2:5]\n    elif last == '3':\n        body = d[0:3] + '00000' + d[3:5]\n    elif last == '4':\n        body = d[0:4] + '00000' + d[4]\n    else:\n        body = d[0:5] + '0000' + last\n    return ns + body + chk\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['25279409', None], ['28680954', None], ['04319958', '043199000058'], ['08023781', '080237000081'], ['01189536', '011800000956'], ['07573327', '075200007337'], ['09341436', '093400000146'], ['24955674', None]], [['27529098', None], ['28046301', None], ['20584835', None], ['06482006', '064000008206'], ['08877566', '088775000066'], ['03074477', '030744000077'], ['01759900', '017000005990'], ['26112800', None]], [['21922317', None], ['19115135', '191100000515'], ['20008097', None], ['00838090', '008380000090'], ['03132457', '031324000057'], ['06980800', '069000008080'], ['04080146', '040800000016'], ['29592260', None]], [['22375285', None], ['17766731', '177600000671'], ['21113550', None], ['00787643', '007870000063'], ['08858661', '088586000061'], ['09720132', '097200000012'], ['06596582', '065965000082'], ['26563639', None]], [['21443122', None], ['13513558', '135135000058'], ['21834264', None], ['03833572', '038335000072'], ['06185620', '061200008560'], ['02180640', '021800000060'], ['01092108', '010000009218'], ['22394703', None]]]\nlabels = [\"regression: number system restriction\", \"repair trap\", \"combined fault\", \"control\", \"control\", \"boundary\", \"boundary\", \"control\"]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"%s %d\" % (labels[i % len(labels)], i), solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"1b9c4806711f93b5cc37af3835673fbdb112c90d37084b7d5fbf9a81d30423c3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(e):\n    if len(e) != 8 or not all(ch in '0123456789' for ch in e):\n        return None\n    ns, d, chk = e[0], e[1:7], e[7]\n    if ns == '':\n        return None\n    last = d[5]\n    if last in '012':\n        body = d[0:2] + last + '0000' + d[2:5]\n    elif last == '3':\n        body = d[0:3] + '00000' + d[3:5]\n    elif last == '4':\n        body = d[0:4] + '00000' + d[4]\n    else:\n        body = d[0:5] + '0000' + last\n    return ns + body + chk\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['25279409', None], ['28680954', None], ['04319958', '043199000058'], ['08023781', '080237000081'], ['01189536', '011800000956'], ['07573327', '075200007337'], ['09341436', '093400000146'], ['24955674', None]], [['27529098', None], ['28046301', None], ['20584835', None], ['06482006', '064000008206'], ['08877566', '088775000066'], ['03074477', '030744000077'], ['01759900', '017000005990'], ['26112800', None]], [['21922317', None], ['19115135', '191100000515'], ['20008097', None], ['00838090', '008380000090'], ['03132457', '031324000057'], ['06980800', '069000008080'], ['04080146', '040800000016'], ['29592260', None]], [['22375285', None], ['17766731', '177600000671'], ['21113550', None], ['00787643', '007870000063'], ['08858661', '088586000061'], ['09720132', '097200000012'], ['06596582', '065965000082'], ['26563639', None]], [['21443122', None], ['13513558', '135135000058'], ['21834264', None], ['03833572', '038335000072'], ['06185620', '061200008560'], ['02180640', '021800000060'], ['01092108', '010000009218'], ['22394703', None]]]\nlabels = [\"regression: number system restriction\", \"repair trap\", \"combined fault\", \"control\", \"control\", \"boundary\", \"boundary\", \"control\"]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"%s %d\" % (labels[i % len(labels)], i), solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"eed2d1d8cf1ba7b8ddfe10eca0861bb794b6eac25c76b99f6c5e62a6060ee6bf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(e):\n    if len(e) != 8 or not all(ch in '0123456789' for ch in e):\n        return None\n    ns, d, chk = e[0], e[1:7], e[7]\n    if ns not in ('0', '1'):\n        return None\n    last = d[5]\n    if last in '012':\n        body = d[0:2] + last + '0000' + d[2:5]\n    elif last == '3':\n        body = d[0:3] + '00000' + d[3:5]\n    elif last == '4':\n        body = d[0:4] + '00000' + d[4]\n    else:\n        body = d[0:5] + '0000' + last\n    return ns + body + chk\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['25279409', None], ['28680954', None], ['04319958', '043199000058'], ['08023781', '080237000081'], ['01189536', '011800000956'], ['07573327', '075200007337'], ['09341436', '093400000146'], ['24955674', None]], [['27529098', None], ['28046301', None], ['20584835', None], ['06482006', '064000008206'], ['08877566', '088775000066'], ['03074477', '030744000077'], ['01759900', '017000005990'], ['26112800', None]], [['21922317', None], ['19115135', '191100000515'], ['20008097', None], ['00838090', '008380000090'], ['03132457', '031324000057'], ['06980800', '069000008080'], ['04080146', '040800000016'], ['29592260', None]], [['22375285', None], ['17766731', '177600000671'], ['21113550', None], ['00787643', '007870000063'], ['08858661', '088586000061'], ['09720132', '097200000012'], ['06596582', '065965000082'], ['26563639', None]], [['21443122', None], ['13513558', '135135000058'], ['21834264', None], ['03833572', '038335000072'], ['06185620', '061200008560'], ['02180640', '021800000060'], ['01092108', '010000009218'], ['22394703', None]]]\nlabels = [\"regression: number system restriction\", \"repair trap\", \"combined fault\", \"control\", \"control\", \"boundary\", \"boundary\", \"control\"]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"%s %d\" % (labels[i % len(labels)], i), solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic bounded teaching model with a stipulated contract; it makes no claim of conformance to any published specification. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-barcode-symbology-encoding-upce-expansion-number-system","generated_at":"2026-09-29T14:49:44.127475+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Retail, logistics, pharmacy and document workflows depend on encoders that produce exactly the module pattern, code-set switches, separators and quiet zones scanners expect; one misplaced module or separator makes a label unreadable or, worse, scan as different data.","repair":"Reject any number system other than 0 or 1.","root_cause":"The number system digit is never restricted to the values UPC-E supports.","sha256":"16908a5490984f94c7e04a0636647f3606bb6f5c6ab73a9f94d0949e75b9e4b5","title":"UPC-E expansion accepts number systems other than 0 and 1 · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.198,"exit_code":1,"observations":[{"actual":"252000007949","check":"regression: number system restriction 0","expected":null,"passed":false},{"actual":"286809000054","check":"repair trap 1","expected":null,"passed":false},{"actual":"043199000058","check":"combined fault 2","expected":"043199000058","passed":true},{"actual":"080237000081","check":"control 3","expected":"080237000081","passed":true},{"actual":"011800000956","check":"control 4","expected":"011800000956","passed":true},{"actual":"075200007337","check":"boundary 5","expected":"075200007337","passed":true},{"actual":"093400000146","check":"boundary 6","expected":"093400000146","passed":true},{"actual":"249556000074","check":"control 7","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: number system restriction 0\", \"actual\": \"252000007949\", \"expected\": null, \"passed\": false}, {\"check\": \"repair trap 1\", \"actual\": \"286809000054\", \"expected\": null, \"passed\": false}, {\"check\": \"combined fault 2\", \"actual\": \"043199000058\", \"expected\": \"043199000058\", \"passed\": true}, {\"check\": \"control 3\", \"actual\": \"080237000081\", \"expected\": \"080237000081\", \"passed\": true}, {\"check\": \"control 4\", \"actual\": \"011800000956\", \"expected\": \"011800000956\", \"passed\": true}, {\"check\": \"boundary 5\", \"actual\": \"075200007337\", \"expected\": \"075200007337\", \"passed\": true}, {\"check\": \"boundary 6\", \"actual\": \"093400000146\", \"expected\": \"093400000146\", \"passed\": true}, {\"check\": \"control 7\", \"actual\": \"249556000074\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.219,"exit_code":1,"observations":[{"actual":"252000007949","check":"regression: number system restriction 0","expected":null,"passed":false},{"actual":"286809000054","check":"repair trap 1","expected":null,"passed":false},{"actual":"043199000058","check":"combined fault 2","expected":"043199000058","passed":true},{"actual":"080237000081","check":"control 3","expected":"080237000081","passed":true},{"actual":"011800000956","check":"control 4","expected":"011800000956","passed":true},{"actual":"075200007337","check":"boundary 5","expected":"075200007337","passed":true},{"actual":"093400000146","check":"boundary 6","expected":"093400000146","passed":true},{"actual":"249556000074","check":"control 7","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: number system restriction 0\", \"actual\": \"252000007949\", \"expected\": null, \"passed\": false}, {\"check\": \"repair trap 1\", \"actual\": \"286809000054\", \"expected\": null, \"passed\": false}, {\"check\": \"combined fault 2\", \"actual\": \"043199000058\", \"expected\": \"043199000058\", \"passed\": true}, {\"check\": \"control 3\", \"actual\": \"080237000081\", \"expected\": \"080237000081\", \"passed\": true}, {\"check\": \"control 4\", \"actual\": \"011800000956\", \"expected\": \"011800000956\", \"passed\": true}, {\"check\": \"boundary 5\", \"actual\": \"075200007337\", \"expected\": \"075200007337\", \"passed\": true}, {\"check\": \"boundary 6\", \"actual\": \"093400000146\", \"expected\": \"093400000146\", \"passed\": true}, {\"check\": \"control 7\", \"actual\": \"249556000074\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.111,"exit_code":0,"observations":[{"actual":null,"check":"regression: number system restriction 0","expected":null,"passed":true},{"actual":null,"check":"repair trap 1","expected":null,"passed":true},{"actual":"043199000058","check":"combined fault 2","expected":"043199000058","passed":true},{"actual":"080237000081","check":"control 3","expected":"080237000081","passed":true},{"actual":"011800000956","check":"control 4","expected":"011800000956","passed":true},{"actual":"075200007337","check":"boundary 5","expected":"075200007337","passed":true},{"actual":"093400000146","check":"boundary 6","expected":"093400000146","passed":true},{"actual":null,"check":"control 7","expected":null,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: number system restriction 0\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"repair trap 1\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"combined fault 2\", \"actual\": \"043199000058\", \"expected\": \"043199000058\", \"passed\": true}, {\"check\": \"control 3\", \"actual\": \"080237000081\", \"expected\": \"080237000081\", \"passed\": true}, {\"check\": \"control 4\", \"actual\": \"011800000956\", \"expected\": \"011800000956\", \"passed\": true}, {\"check\": \"boundary 5\", \"actual\": \"075200007337\", \"expected\": \"075200007337\", \"passed\": true}, {\"check\": \"boundary 6\", \"actual\": \"093400000146\", \"expected\": \"093400000146\", \"passed\": true}, {\"check\": \"control 7\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}