FA-3006 / Text processing / Open access

A terminal line break invents a blank record · case 01

A terminal line break invents a blank record.

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: Apply universal Unicode splitlines without retaining terminators.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Apply universal Unicode splitlines without retaining terminators.

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

Case contract

Apply universal Unicode splitlines without retaining terminators.

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('\n')
    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\r\nb'), ['a', 'b'])
check('boundary 2', solve('a\n'), ['a'])
check('boundary 3', solve(''), [])
check('boundary 4', solve('a\u2028b'), ['a', 'b'])
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\r', 'b']`	`['a', 'b']`	Failed
boundary 2	`['a', '']`	`['a']`	Failed
boundary 3	`['']`	`[]`	Failed
boundary 4	`['a\u2028b']`	`['a', 'b']`	Failed

SHA-256 / 591c17fc691faf3fba23f79c9fd749f47ece0ab231b3a97683f0bd774bc0e9ac

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.rstrip('\r\n').split('\n')
    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\r\nb'), ['a', 'b'])
check('boundary 2', solve('a\n'), ['a'])
check('boundary 3', solve(''), [])
check('boundary 4', solve('a\u2028b'), ['a', 'b'])
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\r', 'b']`	`['a', 'b']`	Failed
boundary 2	`['a']`	`['a']`	Passed
boundary 3	`['']`	`[]`	Failed
boundary 4	`['a\u2028b']`	`['a', 'b']`	Failed

SHA-256 / d16c0f71b50fd2806e8cb0099839a3948f2141e1e3b682865d6d8465bf86f1ac

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.splitlines()
    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\r\nb'), ['a', 'b'])
check('boundary 2', solve('a\n'), ['a'])
check('boundary 3', solve(''), [])
check('boundary 4', solve('a\u2028b'), ['a', 'b'])
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']`	`['a', 'b']`	Passed
boundary 2	`['a']`	`['a']`	Passed
boundary 3	`[]`	`[]`	Passed
boundary 4	`['a', 'b']`	`['a', 'b']`	Passed

SHA-256 / 139c26fffae30cfdf5a37c5a659c303c8dae313956cfeb0cf6418a9e74978f17

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 2026-09-29T14:37:20.012413+00:00.

Case digest / 067cca0ac8a159627bdbb589b008cff37a3b90962ee400e64a44dab5c9daf5da