FA-3826 / Serialization / Open access

A repr conversion is replaced by ordinary string conversion · case 01

A repr conversion is replaced by ordinary string conversion.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation applies an operation whose text or grammar semantics violate this contract: Format value x with repr conversion inside brackets.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Format value x with repr conversion inside brackets.

Unsuccessful approach: The attempted repair handles the primary example but still violates a separate boundary of the same contract.

Case contract

Format value x with repr conversion inside brackets.

Why this case matters

A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return '['+str(x)+']'
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('a'), "['a']")
check('boundary 2', solve('\n'), "['\\n']")
check('boundary 3', solve(3), '[3]')
check('boundary 4', solve(None), '[None]')
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`[a]`	`['a']`	Failed
boundary 2	`[ ]`	`['\n']`	Failed
boundary 3	`[3]`	`[3]`	Passed
boundary 4	`[None]`	`[None]`	Passed

SHA-256 / 259ba6c2217f6aa43089568bfab1abf885c7d8749b835522138771639009c895

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return '['+'"'+str(x)+'"'+']'
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('a'), "['a']")
check('boundary 2', solve('\n'), "['\\n']")
check('boundary 3', solve(3), '[3]')
check('boundary 4', solve(None), '[None]')
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`["a"]`	`['a']`	Failed
boundary 2	`[" "]`	`['\n']`	Failed
boundary 3	`["3"]`	`[3]`	Failed
boundary 4	`["None"]`	`[None]`	Failed

SHA-256 / bd544e29b1263d607e23b2342f28cf27d99e9bafea53f54449cdf78cba34a912

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return '[{!r}]'.format(x)
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('a'), "['a']")
check('boundary 2', solve('\n'), "['\\n']")
check('boundary 3', solve(3), '[3]')
check('boundary 4', solve(None), '[None]')
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`['a']`	`['a']`	Passed
boundary 2	`['\n']`	`['\n']`	Passed
boundary 3	`[3]`	`[3]`	Passed
boundary 4	`[None]`	`[None]`	Passed

SHA-256 / 2a99ef54a3bf4072189a9ea552961c733c27c7ab039bb2ce897deacad206c307

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:37:31.382051+00:00.

Case digest / b1a9aca85bd64b94074576e4b42048741f78a0c742b680fdacea8624bdad3ce1