FA-60813 / Loyalty points ledgers / Member archive

Purchased points with volume bonus: price basis · case 03

Members are charged for the bonus points they receive free.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

Input {requests:[pts], price_per_1000, tiers:[[min_base, bonus_bp]] ascending, annual_limit, bought_ytd}. Each request is floored to whole thousands ("too small" when that is 0). A request whose base would push purchased base points above annual_limit is rejected whole ("limit"); bonus points never count toward the limit. Bonus = floor(base*bp/10000) with bp from the highest tier whose min_base <= this request base. Price = base/1000*price_per_1000. Return {results:[[base,bonus,price]|reason], bought_ytd}.

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
big buy	`{"bought_ytd": 21000, "results": [[21000, 5250, 28600]]}`	`{"bought_ytd": 21000, "results": [[21000, 5250, 23100]]}`	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.