FA-2986 / Text processing / Open access

An assignment value loses embedded equals signs · case 01

An assignment value loses embedded equals signs.

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: Split on the first equals sign, returning key and remainder; absent equals gives an empty remainder.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Split on the first equals sign, returning key and remainder; absent equals gives an empty remainder.

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

Case contract

Split on the first equals sign, returning key and remainder; absent equals gives an empty remainder.

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 [x.split('=')[0],x.split('=')[-1]]
    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=b=c'), ['a', 'b=c'])
check('boundary 2', solve('a'), ['a', ''])
check('boundary 3', solve('=x'), ['', 'x'])
check('boundary 4', solve('a='), ['a', ''])
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', 'c']`	`['a', 'b=c']`	Failed
boundary 2	`['a', 'a']`	`['a', '']`	Failed
boundary 3	`['', 'x']`	`['', 'x']`	Passed
boundary 4	`['a', '']`	`['a', '']`	Passed

SHA-256 / 0a7b6ac9b410b8c2d06080e4a99a23081c7fecf35e236edcfcbdf4833de21c0f

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 x.rsplit('=',1) if '=' in x else [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=b=c'), ['a', 'b=c'])
check('boundary 2', solve('a'), ['a', ''])
check('boundary 3', solve('=x'), ['', 'x'])
check('boundary 4', solve('a='), ['a', ''])
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=b', 'c']`	`['a', 'b=c']`	Failed
boundary 2	`['a', '']`	`['a', '']`	Passed
boundary 3	`['', 'x']`	`['', 'x']`	Passed
boundary 4	`['a', '']`	`['a', '']`	Passed

SHA-256 / cc4264a53801183346d0bf332a7274f4cdf3e4d7ced3b85a8e172576edac182e

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 [x.partition('=')[0],x.partition('=')[2]]
    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=b=c'), ['a', 'b=c'])
check('boundary 2', solve('a'), ['a', ''])
check('boundary 3', solve('=x'), ['', 'x'])
check('boundary 4', solve('a='), ['a', ''])
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', 'b=c']`	`['a', 'b=c']`	Passed
boundary 2	`['a', '']`	`['a', '']`	Passed
boundary 3	`['', 'x']`	`['', 'x']`	Passed
boundary 4	`['a', '']`	`['a', '']`	Passed

SHA-256 / b2a7a166474613b3b67f4e37b7962d98db1f4a865149a0f9f9f068bfa9999bfe

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 2026-09-29T14:37:19.903161+00:00.

Case digest / e6740a69ccc8dc03042b81ca2cb43026c1f71dc3402708f993208cfd857d3496