{"abstract":"Heuristic freshness never exceeds configured cap.","category":"HTTP caching","checks":4,"contract":"Bounded offline decision model: heuristic freshness never exceeds configured cap. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-heuristic-freshness-never-exceeds-configured-cap","failed_approach":"The attempted repair uses `max(cap,max(0,date-modified)*0.1)` and still violates a separate fixture.","family":"xh-heuristic-freshness-never-exceeds-configured-cap","id":"FA-6786","implementations":{"attempt":{"sha256":"aab31ca73d7e17cb049649b1f80bf1e102b4d8c1df3e610c0129e849b5841255","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(date, modified, cap):\n    return max(cap,max(0,date-modified)*0.1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(100, 0, 5), 5)\", \"check('fixture 2', solve(10, 20, 5), 0)\", \"check('fixture 3', solve(10, 0, 5), 1)\", \"check('fixture 4', solve(0, 0, 5), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"4536ae41cc3b247c2fc529d594e8c6cc56d5f977e7e553d43d0320570a52dcb6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(date, modified, cap):\n    return (date-modified)*0.1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(100, 0, 5), 5)\", \"check('fixture 2', solve(10, 20, 5), 0)\", \"check('fixture 3', solve(10, 0, 5), 1)\", \"check('fixture 4', solve(0, 0, 5), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"7b1547a3c4528184c075c8f245009f8abdd031e35e39a41933e681d085412161","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(date, modified, cap):\n    return min(cap,max(0,date-modified)*0.1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(100, 0, 5), 5)\", \"check('fixture 2', solve(10, 20, 5), 0)\", \"check('fixture 3', solve(10, 0, 5), 1)\", \"check('fixture 4', solve(0, 0, 5), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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":"xh-heuristic-freshness-never-exceeds-configured-cap","generated_at":"2026-09-29T14:38:05.123736+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic http caching model isolates the heuristic-freshness-never-exceeds-configured-cap policy at a network component boundary.","repair":"Apply the explicit heuristic-freshness-never-exceeds-configured-cap contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `(date-modified)*0.1` for the heuristic-freshness-never-exceeds-configured-cap decision.","sha256":"861f60f6e143200171785b390ec2409c45f71c44382fb173a15aed99a5e840ca","title":"Heuristic freshness never exceeds configured cap · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.427,"exit_code":1,"observations":[{"actual":5,"check":"fixture 2","expected":0,"passed":false},{"actual":5,"check":"fixture 3","expected":1,"passed":false},{"actual":5,"check":"fixture 4","expected":0,"passed":false},{"actual":10.0,"check":"fixture 1","expected":5,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 5, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 5, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 5, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 1\", \"actual\": 10.0, \"expected\": 5, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":35.505,"exit_code":1,"observations":[{"actual":-1.0,"check":"fixture 2","expected":0,"passed":false},{"actual":1.0,"check":"fixture 3","expected":1,"passed":true},{"actual":0.0,"check":"fixture 4","expected":0,"passed":true},{"actual":10.0,"check":"fixture 1","expected":5,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": -1.0, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 1.0, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 10.0, \"expected\": 5, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":37.522,"exit_code":0,"observations":[{"actual":0.0,"check":"fixture 2","expected":0,"passed":true},{"actual":1.0,"check":"fixture 3","expected":1,"passed":true},{"actual":0.0,"check":"fixture 4","expected":0,"passed":true},{"actual":5,"check":"fixture 1","expected":5,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 1.0, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 5, \"expected\": 5, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}