{"abstract":"A list-valued query field becomes a Python representation.","category":"Serialization","checks":4,"contract":"Encode ordered pairs expanding sequence values into repeated keys.","evaluation_group":"model-ffb78cc99bc1a34d","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-query-sequence-values","id":"FA-3291","implementations":{"attempt":{"sha256":"57a1ec88051c9d23ead44e0d06f9c936c805bf9b1a565261e7eb0de399f975e5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return urlencode([(k,','.join(v) if isinstance(v,list) else v) for k,v in x])\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve([['a', ['1', '2']]]), 'a=1&a=2')\ncheck('boundary 2', solve([['x', []]]), '')\ncheck('boundary 3', solve([['x', 'a b']]), 'x=a+b')\ncheck('boundary 4', solve([['a', ['']]]), 'a=')\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":"dbe3d0d1be33f841f86aaff9ce4f13ac7d586608da4e9f82d037a3946cccd66f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return urlencode(x)\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve([['a', ['1', '2']]]), 'a=1&a=2')\ncheck('boundary 2', solve([['x', []]]), '')\ncheck('boundary 3', solve([['x', 'a b']]), 'x=a+b')\ncheck('boundary 4', solve([['a', ['']]]), 'a=')\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":"5c33bb41b93e3a6f8c9f924dcb7d38f22b49e03088febed71be668de7a736b44","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return urlencode([tuple(p) for p in x],doseq=True)\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve([['a', ['1', '2']]]), 'a=1&a=2')\ncheck('boundary 2', solve([['x', []]]), '')\ncheck('boundary 3', solve([['x', 'a b']]), 'x=a+b')\ncheck('boundary 4', solve([['a', ['']]]), 'a=')\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":" 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":"xp-query-sequence-values","generated_at":"2026-09-29T14:37:23.998117+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.","repair":"Implement the complete stated contract, including the boundary fixtures: Encode ordered pairs expanding sequence values into repeated keys.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Encode ordered pairs expanding sequence values into repeated keys.","sha256":"f89400ea2e8a6d066ddf85d8b952240b5e52cae5bf840339cf436f1575b030b5","title":"A list-valued query field becomes a Python representation · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":53.092,"exit_code":1,"observations":[{"actual":"a=1%2C2","check":"boundary 1","expected":"a=1&a=2","passed":false},{"actual":"x=","check":"boundary 2","expected":"","passed":false},{"actual":"x=a+b","check":"boundary 3","expected":"x=a+b","passed":true},{"actual":"a=","check":"boundary 4","expected":"a=","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"a=1%2C2\", \"expected\": \"a=1&a=2\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"x=\", \"expected\": \"\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"x=a+b\", \"expected\": \"x=a+b\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"a=\", \"expected\": \"a=\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":53.102,"exit_code":1,"observations":[{"actual":{"error":"TypeError"},"check":"boundary 1","expected":"a=1&a=2","passed":false},{"actual":{"error":"TypeError"},"check":"boundary 2","expected":"","passed":false},{"actual":{"error":"TypeError"},"check":"boundary 3","expected":"x=a+b","passed":false},{"actual":{"error":"TypeError"},"check":"boundary 4","expected":"a=","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": {\"error\": \"TypeError\"}, \"expected\": \"a=1&a=2\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": {\"error\": \"TypeError\"}, \"expected\": \"\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": {\"error\": \"TypeError\"}, \"expected\": \"x=a+b\", \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": {\"error\": \"TypeError\"}, \"expected\": \"a=\", \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":65.703,"exit_code":0,"observations":[{"actual":"a=1&a=2","check":"boundary 1","expected":"a=1&a=2","passed":true},{"actual":"","check":"boundary 2","expected":"","passed":true},{"actual":"x=a+b","check":"boundary 3","expected":"x=a+b","passed":true},{"actual":"a=","check":"boundary 4","expected":"a=","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"a=1&a=2\", \"expected\": \"a=1&a=2\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"x=a+b\", \"expected\": \"x=a+b\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"a=\", \"expected\": \"a=\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}