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FA-60351 / Loyalty points ledgers / Open access

Order points earning: minimum spend boundary · case 01

An order of exactly five dollars of eligible spend earns nothing.

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

ROOT CAUSE

The minimum-spend test rejects spend equal to the minimum.

THE FAILURE

The minimum-spend test rejects spend equal to the minimum.

Unsuccessful approach: Lowering the minimum to 499 cents admits orders below the stipulated minimum.

Case contract

Input {lines:[{cat,amount cents}], tax, shipping, tier, promo:{cat:multiplier}}. Eligible spend = non-giftcard line amounts (tax and shipping never earn). Eligible spend below 500 cents earns nothing. Base = floor(eligible/100) computed once per order. Tier points = floor(base*pct/100) with pct base 100, silver 125, gold 150. Promo bonus per non-giftcard category = floor(category spend/100)*(multiplier-1); the order bonus is capped at 1000. Return {base, tier, bonus, total}.

Why this case matters

Member point balances, statements and the program liability depend on this ledger rule.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    elig = sum(l['amount'] for l in x['lines'] if l['cat'] != 'giftcard')
    if elig <= 500:
        return {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}
    base = elig // 100
    tier = base * {'base': 100, 'silver': 125, 'gold': 150}[x['tier']] // 100
    bonus = 0
    for cat, mult in sorted(x['promo'].items()):
        if cat == 'giftcard':
            continue
        amt = sum(l['amount'] for l in x['lines'] if l['cat'] == cat)
        bonus += (amt // 100) * (mult - 1)
    bonus = min(bonus, 1000)
    return {'base': base, 'tier': tier, 'bonus': bonus, 'total': tier + bonus}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['plain order', {'lines': [{'cat': 'grocery', 'amount': 2350}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 851}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1399}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 13, 'tier': 16, 'bonus': 0, 'total': 16}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 41, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 2500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 61000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 620, 'tier': 620, 'bonus': 1000, 'total': 1620}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 200}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3326}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2351}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 852}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1499}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 14, 'tier': 17, 'bonus': 0, 'total': 17}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 42, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 5000}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 62000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 630, 'tier': 630, 'bonus': 1000, 'total': 1630}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 201}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3327}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2352}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 853}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1599}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 15, 'tier': 18, 'bonus': 0, 'total': 18}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 43, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 7500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 63000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 640, 'tier': 640, 'bonus': 1000, 'total': 1640}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 202}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3328}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2353}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 854}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1699}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 16, 'tier': 20, 'bonus': 0, 'total': 20}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 44, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 10000}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 64000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 650, 'tier': 650, 'bonus': 1000, 'total': 1650}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 203}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 8, 'tier': 10, 'bonus': 1, 'total': 11}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3329}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2354}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 855}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1799}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 17, 'tier': 21, 'bonus': 0, 'total': 21}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 45, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 12500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 65000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 660, 'tier': 660, 'bonus': 1000, 'total': 1660}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 204}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 8, 'tier': 10, 'bonus': 1, 'total': 11}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3330}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]]]
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 fixtureActualExpectedOutcome
plain order{'base': 39, 'bonus': 0, 'tier': 39, 'total': 39}{'base': 39, 'bonus': 0, 'tier': 39, 'total': 39}Passed
gold with promo{'base': 159, 'bonus': 300, 'tier': 238, 'total': 538}{'base': 159, 'bonus': 300, 'tier': 238, 'total': 538}Passed
gift card excluded{'base': 13, 'bonus': 0, 'tier': 16, 'total': 16}{'base': 13, 'bonus': 0, 'tier': 16, 'total': 16}Passed
below minimum{'base': 0, 'bonus': 0, 'tier': 0, 'total': 0}{'base': 0, 'bonus': 0, 'tier': 0, 'total': 0}Passed
at minimum{'base': 0, 'bonus': 0, 'tier': 0, 'total': 0}{'base': 5, 'bonus': 0, 'tier': 6, 'total': 6}Failed
bonus cap{'base': 620, 'bonus': 1000, 'tier': 620, 'total': 1620}{'base': 620, 'bonus': 1000, 'tier': 620, 'total': 1620}Passed
cents across lines{'base': 7, 'bonus': 1, 'tier': 8, 'total': 9}{'base': 7, 'bonus': 1, 'tier': 8, 'total': 9}Passed
two promos{'base': 78, 'bonus': 144, 'tier': 117, 'total': 261}{'base': 78, 'bonus': 144, 'tier': 117, 'total': 261}Passed

SHA-256 / 6380e068162f2aaabc2cd55ebd2ffa5880c4f7d477214465fca54c7dd4925c70

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    elig = sum(l['amount'] for l in x['lines'] if l['cat'] != 'giftcard')
    if elig < 499:
        return {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}
    base = elig // 100
    tier = base * {'base': 100, 'silver': 125, 'gold': 150}[x['tier']] // 100
    bonus = 0
    for cat, mult in sorted(x['promo'].items()):
        if cat == 'giftcard':
            continue
        amt = sum(l['amount'] for l in x['lines'] if l['cat'] == cat)
        bonus += (amt // 100) * (mult - 1)
    bonus = min(bonus, 1000)
    return {'base': base, 'tier': tier, 'bonus': bonus, 'total': tier + bonus}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['plain order', {'lines': [{'cat': 'grocery', 'amount': 2350}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 851}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1399}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 13, 'tier': 16, 'bonus': 0, 'total': 16}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 41, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 2500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 61000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 620, 'tier': 620, 'bonus': 1000, 'total': 1620}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 200}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3326}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2351}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 852}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1499}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 14, 'tier': 17, 'bonus': 0, 'total': 17}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 42, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 5000}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 62000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 630, 'tier': 630, 'bonus': 1000, 'total': 1630}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 201}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3327}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2352}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 853}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1599}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 15, 'tier': 18, 'bonus': 0, 'total': 18}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 43, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 7500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 63000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 640, 'tier': 640, 'bonus': 1000, 'total': 1640}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 202}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 7, 'tier': 8, 'bonus': 1, 'total': 9}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3328}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2353}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 854}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1699}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 16, 'tier': 20, 'bonus': 0, 'total': 20}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 44, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 10000}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 64000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 650, 'tier': 650, 'bonus': 1000, 'total': 1650}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 203}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 8, 'tier': 10, 'bonus': 1, 'total': 11}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3329}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]], [['plain order', {'lines': [{'cat': 'grocery', 'amount': 2354}, {'cat': 'home', 'amount': 1575}], 'tax': 300, 'shipping': 499, 'tier': 'base', 'promo': {}}, {'base': 39, 'tier': 39, 'bonus': 0, 'total': 39}], ['gold with promo', {'lines': [{'cat': 'electronics', 'amount': 15099}, {'cat': 'grocery', 'amount': 855}], 'tax': 1200, 'shipping': 0, 'tier': 'gold', 'promo': {'electronics': 3}}, {'base': 159, 'tier': 238, 'bonus': 300, 'total': 538}], ['gift card excluded', {'lines': [{'cat': 'giftcard', 'amount': 5000}, {'cat': 'toys', 'amount': 1799}], 'tax': 100, 'shipping': 0, 'tier': 'silver', 'promo': {'giftcard': 5}}, {'base': 17, 'tier': 21, 'bonus': 0, 'total': 21}], ['below minimum', {'lines': [{'cat': 'toys', 'amount': 499}], 'tax': 45, 'shipping': 800, 'tier': 'gold', 'promo': {}}, {'base': 0, 'tier': 0, 'bonus': 0, 'total': 0}], ['at minimum', {'lines': [{'cat': 'toys', 'amount': 500}, {'cat': 'giftcard', 'amount': 12500}], 'tax': 40, 'shipping': 0, 'tier': 'silver', 'promo': {}}, {'base': 5, 'tier': 6, 'bonus': 0, 'total': 6}], ['bonus cap', {'lines': [{'cat': 'travel', 'amount': 65000}, {'cat': 'travel', 'amount': 1050}], 'tax': 0, 'shipping': 0, 'tier': 'base', 'promo': {'travel': 3, 'food': 2}}, {'base': 660, 'tier': 660, 'bonus': 1000, 'total': 1660}], ['cents across lines', {'lines': [{'cat': 'a', 'amount': 199}, {'cat': 'b', 'amount': 199}, {'cat': 'c', 'amount': 199}, {'cat': 'd', 'amount': 204}], 'tax': 0, 'shipping': 0, 'tier': 'silver', 'promo': {'b': 2}}, {'base': 8, 'tier': 10, 'bonus': 1, 'total': 11}], ['two promos', {'lines': [{'cat': 'shoes', 'amount': 4550}, {'cat': 'bags', 'amount': 3330}], 'tax': 500, 'shipping': 700, 'tier': 'gold', 'promo': {'shoes': 2, 'bags': 4}}, {'base': 78, 'tier': 117, 'bonus': 144, 'total': 261}]]]
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 fixtureActualExpectedOutcome
plain order{'base': 39, 'bonus': 0, 'tier': 39, 'total': 39}{'base': 39, 'bonus': 0, 'tier': 39, 'total': 39}Passed
gold with promo{'base': 159, 'bonus': 300, 'tier': 238, 'total': 538}{'base': 159, 'bonus': 300, 'tier': 238, 'total': 538}Passed
gift card excluded{'base': 13, 'bonus': 0, 'tier': 16, 'total': 16}{'base': 13, 'bonus': 0, 'tier': 16, 'total': 16}Passed
below minimum{'base': 4, 'bonus': 0, 'tier': 6, 'total': 6}{'base': 0, 'bonus': 0, 'tier': 0, 'total': 0}Failed
at minimum{'base': 5, 'bonus': 0, 'tier': 6, 'total': 6}{'base': 5, 'bonus': 0, 'tier': 6, 'total': 6}Passed
bonus cap{'base': 620, 'bonus': 1000, 'tier': 620, 'total': 1620}{'base': 620, 'bonus': 1000, 'tier': 620, 'total': 1620}Passed
cents across lines{'base': 7, 'bonus': 1, 'tier': 8, 'total': 9}{'base': 7, 'bonus': 1, 'tier': 8, 'total': 9}Passed
two promos{'base': 78, 'bonus': 144, 'tier': 117, 'total': 261}{'base': 78, 'bonus': 144, 'tier': 117, 'total': 261}Passed

SHA-256 / e0209eb5609dfc26996cff1d442f9689407f2bff456626b2a5773d711cd755fb

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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.

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Verification & scope

Stipulated bounded loyalty-program model with explicit toy rules; not any real program terms. 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 2026-09-29T14:46:45.003461+00:00.

Case digest / 69e28c6a657c57306a8950f2f191961a663ba36e4367c14e354f245bf2cc5d46