{"abstract":"A vector UDF drops empty successful batches.","category":"Data systems","checks":7,"contract":"Execute a stipulated vector UDF result contract. For every selected batch, output length must equal selected input length, and output validity must have the same length. A malformed batch emits LENGTH_ERROR and no partial values. Valid output values use their own validity and retain selected input identities.","contract_signature":"d","evaluation_group":"s3-data-systems-udf-vector-cardinality","failed_approach":"Dropping empty batches loses one-result-per-invocation correspondence.","family":"s3-data-systems-udf-vector-cardinality-batch-output","id":"FA-45326","implementations":{"attempt":{"sha256":"0a565e7ef4c5266d5bb3917e8f6b0fb78e81219f494f696ad8a9eb6b97ed274b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        out=[]\n        for ids,selection,values,valid in d:\n            selected=[ids[i] for i in selection]\n            if len(values)!=len(selected) or len(valid)!=len(selected):\n                out.append('LENGTH_ERROR'); continue\n            out.append([[ident,values[i] if valid[i] else None] for i,ident in enumerate(selected)])\n        return [batch for batch in out if batch!=[]]\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [1, 2], [True, True]]]), [[[12, 1], [10, 2]]])\n    check('short result', solve([[[10, 11], [0, 1], [1], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [1], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [1, 2], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [1], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 2:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [2, 3], [True, True]]]), [[[12, 2], [10, 3]]])\n    check('short result', solve([[[10, 11], [0, 1], [2], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [2], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [2, 3], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [2], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 3:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [3, 4], [True, True]]]), [[[12, 3], [10, 4]]])\n    check('short result', solve([[[10, 11], [0, 1], [3], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [3], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [3, 4], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [3], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 4:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [4, 5], [True, True]]]), [[[12, 4], [10, 5]]])\n    check('short result', solve([[[10, 11], [0, 1], [4], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [4], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [4, 5], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [4], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 5:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [5, 6], [True, True]]]), [[[12, 5], [10, 6]]])\n    check('short result', solve([[[10, 11], [0, 1], [5], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [5], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [5, 6], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [5], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\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":"41bba45e7e7fac8423cd35ac0ffd1a603315c4a61797340a72015da7f3326e52","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        out=[]\n        for ids,selection,values,valid in d:\n            selected=[ids[i] for i in selection]\n            if len(values)!=len(selected) or len(valid)!=len(selected):\n                out.append('LENGTH_ERROR'); continue\n            out.append([[ident,values[i] if valid[i] else None] for i,ident in enumerate(selected)])\n        return [batch for batch in out if batch]\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [1, 2], [True, True]]]), [[[12, 1], [10, 2]]])\n    check('short result', solve([[[10, 11], [0, 1], [1], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [1], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [1, 2], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [1], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 2:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [2, 3], [True, True]]]), [[[12, 2], [10, 3]]])\n    check('short result', solve([[[10, 11], [0, 1], [2], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [2], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [2, 3], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [2], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 3:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [3, 4], [True, True]]]), [[[12, 3], [10, 4]]])\n    check('short result', solve([[[10, 11], [0, 1], [3], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [3], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [3, 4], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [3], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 4:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [4, 5], [True, True]]]), [[[12, 4], [10, 5]]])\n    check('short result', solve([[[10, 11], [0, 1], [4], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [4], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [4, 5], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [4], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\nelif N == 5:\n    check('selected ids', solve([[[10, 11, 12], [2, 0], [5, 6], [True, True]]]), [[[12, 5], [10, 6]]])\n    check('short result', solve([[[10, 11], [0, 1], [5], [True, True]]]), ['LENGTH_ERROR'])\n    check('long validity', solve([[[10], [0], [5], [True, False]]]), ['LENGTH_ERROR'])\n    check('short validity', solve([[[10, 11], [0, 1], [5, 6], [True]]]), ['LENGTH_ERROR'])\n    check('null output', solve([[[10], [0], [5], [False]]]), [[[10, None]]])\n    check('empty result', solve([[[10], [], [], []]]), [[]])\n    check('no invocations', solve([]), [])\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":"Offline stipulated semantics over valid small inputs; no performance, concurrency, or production-engine conformance claim. 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":"s3-data-systems-udf-vector-cardinality-batch-output","generated_at":"2026-09-29T14:44:21.067763+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded deterministic data engine model makes representation and changelog faults reproducible.","root_cause":"udf-vector-cardinality: A vector UDF drops empty successful batches.","sha256":"c7498eeef1e81eee9b1778757cce3e1dac35ee58417f895257908412588fdb42","title":"A vector UDF drops empty successful batches · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":49.828,"exit_code":1,"observations":[{"actual":[[[12,1],[10,2]]],"check":"selected ids","expected":[[[12,1],[10,2]]],"passed":true},{"actual":["LENGTH_ERROR"],"check":"short result","expected":["LENGTH_ERROR"],"passed":true},{"actual":["LENGTH_ERROR"],"check":"long validity","expected":["LENGTH_ERROR"],"passed":true},{"actual":["LENGTH_ERROR"],"check":"short validity","expected":["LENGTH_ERROR"],"passed":true},{"actual":[[[10,null]]],"check":"null output","expected":[[[10,null]]],"passed":true},{"actual":[],"check":"empty result","expected":[[]],"passed":false},{"actual":[],"check":"no invocations","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"selected ids\", \"actual\": [[[12, 1], [10, 2]]], \"expected\": [[[12, 1], [10, 2]]], \"passed\": true}, {\"check\": \"short result\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"long validity\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"short validity\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"null output\", \"actual\": [[[10, null]]], \"expected\": [[[10, null]]], \"passed\": true}, {\"check\": \"empty result\", \"actual\": [], \"expected\": [[]], \"passed\": false}, {\"check\": \"no invocations\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":47.139,"exit_code":1,"observations":[{"actual":[[[12,1],[10,2]]],"check":"selected ids","expected":[[[12,1],[10,2]]],"passed":true},{"actual":["LENGTH_ERROR"],"check":"short result","expected":["LENGTH_ERROR"],"passed":true},{"actual":["LENGTH_ERROR"],"check":"long validity","expected":["LENGTH_ERROR"],"passed":true},{"actual":["LENGTH_ERROR"],"check":"short validity","expected":["LENGTH_ERROR"],"passed":true},{"actual":[[[10,null]]],"check":"null output","expected":[[[10,null]]],"passed":true},{"actual":[],"check":"empty result","expected":[[]],"passed":false},{"actual":[],"check":"no invocations","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"selected ids\", \"actual\": [[[12, 1], [10, 2]]], \"expected\": [[[12, 1], [10, 2]]], \"passed\": true}, {\"check\": \"short result\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"long validity\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"short validity\", \"actual\": [\"LENGTH_ERROR\"], \"expected\": [\"LENGTH_ERROR\"], \"passed\": true}, {\"check\": \"null output\", \"actual\": [[[10, null]]], \"expected\": [[[10, null]]], \"passed\": true}, {\"check\": \"empty result\", \"actual\": [], \"expected\": [[]], \"passed\": false}, {\"check\": \"no invocations\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}