FA-60453 / Loyalty points ledgers / Member archive

Rolling tier qualification with soft landing: highest tier met · case 03

A member who qualifies for gold is only granted silver.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Input {events:[[month,qualifying pts]], eval_month, current_tier, thresholds}. Qualifying points are summed over months eval-11..eval inclusive. The earned tier is the highest tier whose threshold is met (>=). Upgrades take effect fully; downgrades drop at most one level per evaluation. Tiers: member < silver < gold < platinum. Return {qualifying, earned, tier}.

Why this case matters

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

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
upgrade	`{"earned": "silver", "qualifying": 15503, "tier": "silver"}`	`{"earned": "gold", "qualifying": 15503, "tier": "gold"}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.