FA-66386 / Airline fare rule evaluation / Open access
Saturday-night rule applied when disabled · case 01
Fares whose rule explicitly sets sat_night to false still report SAT failures.
ROOT CAUSE
The code tests for the key being present instead of its boolean value.
VERIFIED REPAIR
Apply the Saturday-night rule only when the flag is true.
Unsuccessful approach: Testing for None still treats an explicit false as enabled.
Case contract
Input {'depart','return' ISO dates,'rule':{'sat_night','min_days','max_months'}}. Saturday-night rule: return on or after the Sunday following the first Saturday on or after departure. Min stay: return - depart >= min_days. Max stay: return <= departure date plus max_months calendar months; a month-end departure maps to the target month end, otherwise day clamps to month length. Return failed rule names in order SAT, MIN, MAX.
Why this case matters
Stay restrictions mix weekday logic and calendar-month arithmetic with month-end and year-rollover rules.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import datetime
import calendar
N = 1
observations = []
def solve(x):
d = datetime.date.fromisoformat(x['depart'])
r = datetime.date.fromisoformat(x['return'])
rule = x['rule']
fails = []
if 'sat_night' in rule:
sun = d + datetime.timedelta(days=(5 - d.weekday()) % 7 + 1)
if r < sun: fails.append('SAT')
if (r - d).days < rule['min_days']: fails.append('MIN')
mo = d.month - 1 + rule['max_months']
y, mo = d.year + mo // 12, mo % 12 + 1
last = calendar.monthrange(y, mo)[1]
eom = d.day == calendar.monthrange(d.year, d.month)[1]
lim = datetime.date(y, mo, last if eom else min(d.day, last))
if r > lim: fails.append('MAX')
return fails
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-08', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-11', 'return': '2028-01-10', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-14', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-08-19', 'return': '2029-08-28', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, []], ['sampled case 2', {'depart': '2028-06-13', 'return': '2028-12-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['sampled case 3', {'depart': '2028-04-16', 'return': '2028-08-20', 'rule': {'sat_night': False, 'min_days': 1, 'max_months': 1}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-08-06', 'return': '2028-08-07', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, ['MIN']]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-09', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-12', 'return': '2028-01-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-15', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-07-11', 'return': '2029-07-23', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 12}}, []], ['sampled case 2', {'depart': '2029-06-25', 'return': '2029-12-12', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, ['MAX']], ['sampled case 3', {'depart': '2029-02-02', 'return': '2030-02-22', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-02-01', 'return': '2028-02-04', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 2}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-10', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-29', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-29', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-13', 'return': '2028-01-14', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-16', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-10-05', 'return': '2027-10-14', 'rule': {'sat_night': True, 'min_days': 3, 'max_months': 6}}, []], ['sampled case 2', {'depart': '2028-04-06', 'return': '2028-10-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-11-12', 'return': '2027-11-21', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 2}}, []], ['regression: Saturday rule applicability', {'depart': '2028-04-03', 'return': '2028-04-08', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-11', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-14', 'return': '2028-01-16', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-17', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-06-01', 'return': '2027-06-09', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 1}}, []], ['sampled case 2', {'depart': '2028-03-04', 'return': '2028-06-07', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, []], ['sampled case 3', {'depart': '2029-03-17', 'return': '2029-03-25', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['regression: Saturday rule applicability', {'depart': '2029-04-18', 'return': '2029-04-21', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 11}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-12', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-15', 'return': '2028-01-18', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-18', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2029-08-05', 'return': '2030-07-02', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 11}}, []], ['sampled case 2', {'depart': '2028-05-10', 'return': '2028-05-12', 'rule': {'sat_night': False, 'min_days': 2, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-09-03', 'return': '2027-09-03', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 6}}, ['SAT']]]]
for label, args, expected in fixtures[N-1]:
check(label, solve(args), expected)
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 |
|---|---|---|---|
| Sunday departure next-day return | ['SAT'] | ['SAT'] | Passed |
| Saturday departure Sunday return | [] | [] | Passed |
| Friday out Saturday back | ['SAT'] | ['SAT'] | Passed |
| month-end max stay | [] | [] | Passed |
| the 28th is not month end | ['MAX'] | ['MAX'] | Passed |
| Jan 31 plus one month | [] | [] | Passed |
| year rollover max stay | [] | [] | Passed |
| exact minimum stay | [] | [] | Passed |
| December twelve months | [] | [] | Passed |
| sampled case 1 | [] | [] | Passed |
| sampled case 2 | [] | [] | Passed |
| sampled case 3 | ['MAX'] | ['MAX'] | Passed |
| regression: Saturday rule applicability | ['SAT', 'MIN'] | ['MIN'] | Failed |
SHA-256 / 97fc5ae62bc155091dbb82ea4fd06de0aaabb7cf2dee4fd89f392b742b48db8b
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import datetime
import calendar
N = 1
observations = []
def solve(x):
d = datetime.date.fromisoformat(x['depart'])
r = datetime.date.fromisoformat(x['return'])
rule = x['rule']
fails = []
if rule['sat_night'] is not None:
sun = d + datetime.timedelta(days=(5 - d.weekday()) % 7 + 1)
if r < sun: fails.append('SAT')
if (r - d).days < rule['min_days']: fails.append('MIN')
mo = d.month - 1 + rule['max_months']
y, mo = d.year + mo // 12, mo % 12 + 1
last = calendar.monthrange(y, mo)[1]
eom = d.day == calendar.monthrange(d.year, d.month)[1]
lim = datetime.date(y, mo, last if eom else min(d.day, last))
if r > lim: fails.append('MAX')
return fails
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-08', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-11', 'return': '2028-01-10', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-14', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-08-19', 'return': '2029-08-28', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, []], ['sampled case 2', {'depart': '2028-06-13', 'return': '2028-12-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['sampled case 3', {'depart': '2028-04-16', 'return': '2028-08-20', 'rule': {'sat_night': False, 'min_days': 1, 'max_months': 1}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-08-06', 'return': '2028-08-07', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, ['MIN']]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-09', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-12', 'return': '2028-01-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-15', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-07-11', 'return': '2029-07-23', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 12}}, []], ['sampled case 2', {'depart': '2029-06-25', 'return': '2029-12-12', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, ['MAX']], ['sampled case 3', {'depart': '2029-02-02', 'return': '2030-02-22', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-02-01', 'return': '2028-02-04', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 2}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-10', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-29', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-29', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-13', 'return': '2028-01-14', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-16', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-10-05', 'return': '2027-10-14', 'rule': {'sat_night': True, 'min_days': 3, 'max_months': 6}}, []], ['sampled case 2', {'depart': '2028-04-06', 'return': '2028-10-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-11-12', 'return': '2027-11-21', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 2}}, []], ['regression: Saturday rule applicability', {'depart': '2028-04-03', 'return': '2028-04-08', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-11', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-14', 'return': '2028-01-16', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-17', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-06-01', 'return': '2027-06-09', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 1}}, []], ['sampled case 2', {'depart': '2028-03-04', 'return': '2028-06-07', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, []], ['sampled case 3', {'depart': '2029-03-17', 'return': '2029-03-25', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['regression: Saturday rule applicability', {'depart': '2029-04-18', 'return': '2029-04-21', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 11}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-12', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-15', 'return': '2028-01-18', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-18', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2029-08-05', 'return': '2030-07-02', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 11}}, []], ['sampled case 2', {'depart': '2028-05-10', 'return': '2028-05-12', 'rule': {'sat_night': False, 'min_days': 2, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-09-03', 'return': '2027-09-03', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 6}}, ['SAT']]]]
for label, args, expected in fixtures[N-1]:
check(label, solve(args), expected)
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 |
|---|---|---|---|
| Sunday departure next-day return | ['SAT'] | ['SAT'] | Passed |
| Saturday departure Sunday return | [] | [] | Passed |
| Friday out Saturday back | ['SAT'] | ['SAT'] | Passed |
| month-end max stay | [] | [] | Passed |
| the 28th is not month end | ['MAX'] | ['MAX'] | Passed |
| Jan 31 plus one month | [] | [] | Passed |
| year rollover max stay | [] | [] | Passed |
| exact minimum stay | [] | [] | Passed |
| December twelve months | [] | [] | Passed |
| sampled case 1 | [] | [] | Passed |
| sampled case 2 | [] | [] | Passed |
| sampled case 3 | ['MAX'] | ['MAX'] | Passed |
| regression: Saturday rule applicability | ['SAT', 'MIN'] | ['MIN'] | Failed |
SHA-256 / 4a9618b2a981b52870c8db26efbaa8b7d9a051559cf567c04568cafc2fe5fe0d
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import datetime
import calendar
N = 1
observations = []
def solve(x):
d = datetime.date.fromisoformat(x['depart'])
r = datetime.date.fromisoformat(x['return'])
rule = x['rule']
fails = []
if rule['sat_night']:
sun = d + datetime.timedelta(days=(5 - d.weekday()) % 7 + 1)
if r < sun: fails.append('SAT')
if (r - d).days < rule['min_days']: fails.append('MIN')
mo = d.month - 1 + rule['max_months']
y, mo = d.year + mo // 12, mo % 12 + 1
last = calendar.monthrange(y, mo)[1]
eom = d.day == calendar.monthrange(d.year, d.month)[1]
lim = datetime.date(y, mo, last if eom else min(d.day, last))
if r > lim: fails.append('MAX')
return fails
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-08', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-11', 'return': '2028-01-10', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-14', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-08-19', 'return': '2029-08-28', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, []], ['sampled case 2', {'depart': '2028-06-13', 'return': '2028-12-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['sampled case 3', {'depart': '2028-04-16', 'return': '2028-08-20', 'rule': {'sat_night': False, 'min_days': 1, 'max_months': 1}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-08-06', 'return': '2028-08-07', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, ['MIN']]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-09', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-12', 'return': '2028-01-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, []], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-15', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, []], ['sampled case 1', {'depart': '2029-07-11', 'return': '2029-07-23', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 12}}, []], ['sampled case 2', {'depart': '2029-06-25', 'return': '2029-12-12', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 2}}, ['MAX']], ['sampled case 3', {'depart': '2029-02-02', 'return': '2030-02-22', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, ['MAX']], ['regression: Saturday rule applicability', {'depart': '2028-02-01', 'return': '2028-02-04', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 2}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-10', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-29', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-29', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-13', 'return': '2028-01-14', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-16', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-10-05', 'return': '2027-10-14', 'rule': {'sat_night': True, 'min_days': 3, 'max_months': 6}}, []], ['sampled case 2', {'depart': '2028-04-06', 'return': '2028-10-12', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-11-12', 'return': '2027-11-21', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 2}}, []], ['regression: Saturday rule applicability', {'depart': '2028-04-03', 'return': '2028-04-08', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 3}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-11', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-30', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-30', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-14', 'return': '2028-01-16', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-17', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2027-06-01', 'return': '2027-06-09', 'rule': {'sat_night': True, 'min_days': 7, 'max_months': 1}}, []], ['sampled case 2', {'depart': '2028-03-04', 'return': '2028-06-07', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 6}}, []], ['sampled case 3', {'depart': '2029-03-17', 'return': '2029-03-25', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 12}}, []], ['regression: Saturday rule applicability', {'depart': '2029-04-18', 'return': '2029-04-21', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 11}}, []]], [['Sunday departure next-day return', {'depart': '2027-03-07', 'return': '2027-03-12', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 1}}, ['SAT']], ['Saturday departure Sunday return', {'depart': '2027-03-13', 'return': '2027-03-14', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 1}}, []], ['Friday out Saturday back', {'depart': '2027-03-12', 'return': '2027-03-13', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 3}}, ['SAT']], ['month-end max stay', {'depart': '2027-02-28', 'return': '2027-03-31', 'rule': {'sat_night': False, 'min_days': 3, 'max_months': 1}}, []], ['the 28th is not month end', {'depart': '2027-04-28', 'return': '2027-05-31', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, ['MAX']], ['Jan 31 plus one month', {'depart': '2027-01-31', 'return': '2027-02-28', 'rule': {'sat_night': False, 'min_days': 0, 'max_months': 1}}, []], ['year rollover max stay', {'depart': '2027-11-15', 'return': '2028-01-18', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 2}}, ['MAX']], ['exact minimum stay', {'depart': '2027-06-01', 'return': '2027-06-08', 'rule': {'sat_night': False, 'min_days': 7, 'max_months': 12}}, []], ['December twelve months', {'depart': '2027-12-15', 'return': '2028-12-18', 'rule': {'sat_night': True, 'min_days': 2, 'max_months': 12}}, ['MAX']], ['sampled case 1', {'depart': '2029-08-05', 'return': '2030-07-02', 'rule': {'sat_night': True, 'min_days': 1, 'max_months': 11}}, []], ['sampled case 2', {'depart': '2028-05-10', 'return': '2028-05-12', 'rule': {'sat_night': False, 'min_days': 2, 'max_months': 11}}, []], ['sampled case 3', {'depart': '2027-09-03', 'return': '2027-09-03', 'rule': {'sat_night': True, 'min_days': 0, 'max_months': 6}}, ['SAT']]]]
for label, args, expected in fixtures[N-1]:
check(label, solve(args), expected)
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 |
|---|---|---|---|
| Sunday departure next-day return | ['SAT'] | ['SAT'] | Passed |
| Saturday departure Sunday return | [] | [] | Passed |
| Friday out Saturday back | ['SAT'] | ['SAT'] | Passed |
| month-end max stay | [] | [] | Passed |
| the 28th is not month end | ['MAX'] | ['MAX'] | Passed |
| Jan 31 plus one month | [] | [] | Passed |
| year rollover max stay | [] | [] | Passed |
| exact minimum stay | [] | [] | Passed |
| December twelve months | [] | [] | Passed |
| sampled case 1 | [] | [] | Passed |
| sampled case 2 | [] | [] | Passed |
| sampled case 3 | ['MAX'] | ['MAX'] | Passed |
| regression: Saturday rule applicability | ['MIN'] | ['MIN'] | Passed |
SHA-256 / 826e1fcd78490250ccdae9850c6cb77af7bf9e4e1feb734d6d46acba7980bd96
Verification & scope
A stipulated toy fare-rule contract with invented constants; it is not an ATPCO or carrier tariff implementation and makes no claim of industry-standard conformance. 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 2026-09-29T14:47:43.166138+00:00.
Case digest / aaa2e296376c6f6ac097543931d4c365479af4ca492cedfd972154990cbc4c6d