FA-95491 / Shipping rate zone lookup / Open access

Rate card: card used on its expiry date · case 01

Shipments on the expiry date are still rated with the expired card.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The expiry comparison treats the expiry date as the last valid day.

THE FAILURE

The expiry comparison treats the expiry date as the last valid day.

Unsuccessful approach: Treating open-ended cards as expired removes all current cards.

Case contract

cards [[card_id, effective_from, expires or None, version]] with dates "Y-M-D" that may lack zero padding. A card applies when effective_from <= ship date < expires. Choose the latest effective_from, then highest version, then smallest card_id. None -> "NO_CARD".

Why this case matters

Carriers publish dated rate cards; each shipment must use the card in force on its ship date.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(cards, ship_date):
    def d(s):
        return tuple(int(x) for x in s.split('-'))
    ship = d(ship_date)
    best = None
    for cid, frm, exp, ver in cards:
        if d(frm) > ship:
            continue
        if exp is not None and ship > d(exp):
            continue
        key = (d(frm), ver)
        if best is None or key > best[0] or (key == best[0] and cid < best[1]):
            best = (key, cid)
    return best[1] if best else 'NO_CARD'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 8', [[['R0', '2026-10-1', '2026-10-1', 1], ['R1', '2026-1-5', None, 3], ['R2', '2026-10-1', '2026-11-1', 3], ['R3', '2026-2-1', None, 3], ['R4', '2026-10-1', None, 3]], '2025-12-31'], 'NO_CARD'], ['generated mix 16', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-9-30', '2026-10-1', 3]], '2026-10-15'], 'R0']], [['generated mix 63', [[['R0', '2025-12-31', None, 3], ['R1', '2026-01-15', None, 3], ['R2', '2026-9-30', '2026-10-1', 2], ['R3', '2026-1-5', '2026-10-1', 2]], '2026-10-1'], 'R1'], ['generated mix 10', [[['R0', '2025-12-31', '2026-2-1', 1], ['R1', '2026-10-1', '2026-11-1', 3], ['R2', '2026-11-1', None, 1], ['R3', '2026-01-15', None, 3], ['R4', '2026-1-5', '2026-10-1', 3]], '2026-2-1'], 'R3'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['generated mix 9', [[['R0', '2026-01-15', '2026-2-1', 1], ['R1', '2025-12-31', '2026-2-1', 3], ['R2', '2026-9-30', '2026-10-1', 3], ['R3', '2026-10-1', '2026-2-1', 1]], '2025-12-31'], 'R1'], ['generated mix 18', [[['R0', '2026-10-1', None, 3], ['R1', '2026-10-1', None, 2], ['R2', '2026-10-1', '2026-2-1', 1], ['R3', '2026-01-15', '2026-2-1', 2], ['R4', '2025-12-31', '2026-11-1', 3]], '2026-10-15'], 'R0'], ['generated mix 26', [[['R0', '2026-2-1', None, 2], ['R1', '2025-12-31', '2026-11-1', 3], ['R2', '2025-12-31', None, 2], ['R3', '2026-9-30', None, 2]], '2026-3-15'], 'R0']], [['generated mix 37', [[['R0', '2026-9-30', '2026-10-1', 2], ['R1', '2026-2-1', None, 1], ['R2', '2026-1-5', None, 2], ['R3', '2026-11-1', '2026-11-1', 1], ['R4', '2026-1-5', '2026-2-1', 3]], '2026-11-1'], 'R1'], ['generated mix 20', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-11-1', None, 3], ['R2', '2026-9-30', None, 3], ['R3', '2025-12-31', None, 1]], '2026-2-1'], 'R3'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 21', [[['R0', '2026-2-1', '2026-10-1', 1], ['R1', '2026-10-1', '2026-10-1', 2], ['R2', '2026-2-1', '2026-11-1', 1], ['R3', '2026-01-15', '2026-10-1', 2], ['R4', '2026-1-5', '2026-2-1', 1]], '2026-1-5'], 'R4'], ['generated mix 29', [[['R0', '2026-11-1', '2026-11-1', 2]], '2026-1-5'], 'NO_CARD'], ['generated mix 38', [[['R0', '2026-10-1', '2026-2-1', 2], ['R1', '2026-01-15', '2026-10-1', 1], ['R2', '2026-1-5', None, 1], ['R3', '2026-1-5', '2026-11-1', 3]], '2026-10-15'], 'R3']], [['generated mix 75', [[['R0', '2026-01-15', '2026-2-1', 3], ['R1', '2026-2-1', None, 3], ['R2', '2026-10-1', '2026-10-1', 1], ['R3', '2026-1-5', '2026-10-1', 2], ['R4', '2025-12-31', None, 2]], '2026-10-1'], 'R1'], ['generated mix 32', [[['R0', '2026-2-1', None, 1]], '2026-10-1'], 'R0'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['generated mix 31', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-01-15', None, 3], ['R2', '2026-10-1', None, 3], ['R3', '2026-10-1', '2026-2-1', 2], ['R4', '2026-11-1', '2026-11-1', 2]], '2026-10-15'], 'R2'], ['generated mix 40', [[['R0', '2026-10-1', '2026-2-1', 1], ['R1', '2026-11-1', '2026-2-1', 2], ['R2', '2026-9-30', None, 2], ['R3', '2026-1-5', '2026-2-1', 1]], '2025-12-31'], 'NO_CARD'], ['generated mix 48', [[['R0', '2026-10-1', None, 1], ['R1', '2026-9-30', '2026-2-1', 3], ['R2', '2026-2-1', None, 3], ['R3', '2025-12-31', '2026-2-1', 3]], '2026-3-15'], 'R2']], [['generated mix 51', [[['R0', '2026-9-30', '2026-10-1', 2], ['R1', '2026-1-5', None, 3], ['R2', '2026-01-15', None, 2], ['R3', '2026-2-1', '2026-11-1', 2]], '2026-10-1'], 'R3'], ['generated mix 46', [[['R0', '2026-1-5', '2026-2-1', 3], ['R1', '2026-11-1', '2026-10-1', 2], ['R2', '2026-2-1', None, 2], ['R3', '2026-10-1', None, 2]], '2026-9-30'], 'R2'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 42', [[['R0', '2026-2-1', '2026-2-1', 2]], '2026-2-1'], 'NO_CARD'], ['generated mix 52', [[['R0', '2026-11-1', '2026-2-1', 3], ['R1', '2026-11-1', '2026-2-1', 1], ['R2', '2026-1-5', '2026-10-1', 2], ['R3', '2026-9-30', None, 1]], '2026-2-1'], 'R2'], ['generated mix 60', [[['R0', '2025-12-31', None, 1], ['R1', '2026-1-5', None, 3], ['R2', '2026-10-1', '2026-11-1', 1], ['R3', '2026-01-15', '2026-2-1', 1], ['R4', '2026-01-15', None, 2]], '2025-12-31'], 'R0']]]
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
expiry exclusive	`A`	`B`	Failed
unpadded month	`B`	`B`	Passed
version tie	`B`	`B`	Passed
future only	`NO_CARD`	`NO_CARD`	Passed
effective same day	`A`	`A`	Passed
id tie	`M`	`M`	Passed
generated mix 8	`NO_CARD`	`NO_CARD`	Passed
generated mix 16	`R0`	`R0`	Passed

SHA-256 / 7a4368ccb31d08d4357382440bcd1ba8750114cd50320b4376b657073b18b64c

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(cards, ship_date):
    def d(s):
        return tuple(int(x) for x in s.split('-'))
    ship = d(ship_date)
    best = None
    for cid, frm, exp, ver in cards:
        if d(frm) > ship:
            continue
        if exp is None or ship >= d(exp):
            continue
        key = (d(frm), ver)
        if best is None or key > best[0] or (key == best[0] and cid < best[1]):
            best = (key, cid)
    return best[1] if best else 'NO_CARD'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 8', [[['R0', '2026-10-1', '2026-10-1', 1], ['R1', '2026-1-5', None, 3], ['R2', '2026-10-1', '2026-11-1', 3], ['R3', '2026-2-1', None, 3], ['R4', '2026-10-1', None, 3]], '2025-12-31'], 'NO_CARD'], ['generated mix 16', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-9-30', '2026-10-1', 3]], '2026-10-15'], 'R0']], [['generated mix 63', [[['R0', '2025-12-31', None, 3], ['R1', '2026-01-15', None, 3], ['R2', '2026-9-30', '2026-10-1', 2], ['R3', '2026-1-5', '2026-10-1', 2]], '2026-10-1'], 'R1'], ['generated mix 10', [[['R0', '2025-12-31', '2026-2-1', 1], ['R1', '2026-10-1', '2026-11-1', 3], ['R2', '2026-11-1', None, 1], ['R3', '2026-01-15', None, 3], ['R4', '2026-1-5', '2026-10-1', 3]], '2026-2-1'], 'R3'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['generated mix 9', [[['R0', '2026-01-15', '2026-2-1', 1], ['R1', '2025-12-31', '2026-2-1', 3], ['R2', '2026-9-30', '2026-10-1', 3], ['R3', '2026-10-1', '2026-2-1', 1]], '2025-12-31'], 'R1'], ['generated mix 18', [[['R0', '2026-10-1', None, 3], ['R1', '2026-10-1', None, 2], ['R2', '2026-10-1', '2026-2-1', 1], ['R3', '2026-01-15', '2026-2-1', 2], ['R4', '2025-12-31', '2026-11-1', 3]], '2026-10-15'], 'R0'], ['generated mix 26', [[['R0', '2026-2-1', None, 2], ['R1', '2025-12-31', '2026-11-1', 3], ['R2', '2025-12-31', None, 2], ['R3', '2026-9-30', None, 2]], '2026-3-15'], 'R0']], [['generated mix 37', [[['R0', '2026-9-30', '2026-10-1', 2], ['R1', '2026-2-1', None, 1], ['R2', '2026-1-5', None, 2], ['R3', '2026-11-1', '2026-11-1', 1], ['R4', '2026-1-5', '2026-2-1', 3]], '2026-11-1'], 'R1'], ['generated mix 20', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-11-1', None, 3], ['R2', '2026-9-30', None, 3], ['R3', '2025-12-31', None, 1]], '2026-2-1'], 'R3'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 21', [[['R0', '2026-2-1', '2026-10-1', 1], ['R1', '2026-10-1', '2026-10-1', 2], ['R2', '2026-2-1', '2026-11-1', 1], ['R3', '2026-01-15', '2026-10-1', 2], ['R4', '2026-1-5', '2026-2-1', 1]], '2026-1-5'], 'R4'], ['generated mix 29', [[['R0', '2026-11-1', '2026-11-1', 2]], '2026-1-5'], 'NO_CARD'], ['generated mix 38', [[['R0', '2026-10-1', '2026-2-1', 2], ['R1', '2026-01-15', '2026-10-1', 1], ['R2', '2026-1-5', None, 1], ['R3', '2026-1-5', '2026-11-1', 3]], '2026-10-15'], 'R3']], [['generated mix 75', [[['R0', '2026-01-15', '2026-2-1', 3], ['R1', '2026-2-1', None, 3], ['R2', '2026-10-1', '2026-10-1', 1], ['R3', '2026-1-5', '2026-10-1', 2], ['R4', '2025-12-31', None, 2]], '2026-10-1'], 'R1'], ['generated mix 32', [[['R0', '2026-2-1', None, 1]], '2026-10-1'], 'R0'], ['version tie', [[['A', '2026-1-1', None, 1], ['B', '2026-1-1', None, 2]], '2026-5-1'], 'B'], ['future only', [[['A', '2027-1-1', None, 1]], '2026-5-1'], 'NO_CARD'], ['expiry exclusive', [[['A', '2026-1-1', '2026-3-1', 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'B'], ['generated mix 31', [[['R0', '2026-9-30', '2026-11-1', 1], ['R1', '2026-01-15', None, 3], ['R2', '2026-10-1', None, 3], ['R3', '2026-10-1', '2026-2-1', 2], ['R4', '2026-11-1', '2026-11-1', 2]], '2026-10-15'], 'R2'], ['generated mix 40', [[['R0', '2026-10-1', '2026-2-1', 1], ['R1', '2026-11-1', '2026-2-1', 2], ['R2', '2026-9-30', None, 2], ['R3', '2026-1-5', '2026-2-1', 1]], '2025-12-31'], 'NO_CARD'], ['generated mix 48', [[['R0', '2026-10-1', None, 1], ['R1', '2026-9-30', '2026-2-1', 3], ['R2', '2026-2-1', None, 3], ['R3', '2025-12-31', '2026-2-1', 3]], '2026-3-15'], 'R2']], [['generated mix 51', [[['R0', '2026-9-30', '2026-10-1', 2], ['R1', '2026-1-5', None, 3], ['R2', '2026-01-15', None, 2], ['R3', '2026-2-1', '2026-11-1', 2]], '2026-10-1'], 'R3'], ['generated mix 46', [[['R0', '2026-1-5', '2026-2-1', 3], ['R1', '2026-11-1', '2026-10-1', 2], ['R2', '2026-2-1', None, 2], ['R3', '2026-10-1', None, 2]], '2026-9-30'], 'R2'], ['unpadded month', [[['A', '2026-2-1', None, 1], ['B', '2026-10-1', None, 1]], '2026-10-15'], 'B'], ['effective same day', [[['A', '2026-3-1', None, 1], ['B', '2025-1-1', None, 1]], '2026-3-1'], 'A'], ['id tie', [[['Z', '2026-1-1', None, 2], ['M', '2026-1-1', None, 2]], '2026-5-1'], 'M'], ['generated mix 42', [[['R0', '2026-2-1', '2026-2-1', 2]], '2026-2-1'], 'NO_CARD'], ['generated mix 52', [[['R0', '2026-11-1', '2026-2-1', 3], ['R1', '2026-11-1', '2026-2-1', 1], ['R2', '2026-1-5', '2026-10-1', 2], ['R3', '2026-9-30', None, 1]], '2026-2-1'], 'R2'], ['generated mix 60', [[['R0', '2025-12-31', None, 1], ['R1', '2026-1-5', None, 3], ['R2', '2026-10-1', '2026-11-1', 1], ['R3', '2026-01-15', '2026-2-1', 1], ['R4', '2026-01-15', None, 2]], '2025-12-31'], 'R0']]]
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
expiry exclusive	`NO_CARD`	`B`	Failed
unpadded month	`NO_CARD`	`B`	Failed
version tie	`NO_CARD`	`B`	Failed
future only	`NO_CARD`	`NO_CARD`	Passed
effective same day	`NO_CARD`	`A`	Failed
id tie	`NO_CARD`	`M`	Failed
generated mix 8	`NO_CARD`	`NO_CARD`	Passed
generated mix 16	`R0`	`R0`	Passed

SHA-256 / fa8ff97b5c3c8c86193046fe2a7860d07a42ed34ed00a888e215a1efe64f9d56

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

Stipulated date format and selection policy. 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 2026-09-29T14:52:14.229600+00:00.

Case digest / 5a6cfc07a87983bd99539fec46c60429b3129f02a7401449b7824f08c6c59ff2