FA-60465 / Loyalty points ledgers / Member archive

Refund points clawback: cumulative rounding · case 05

Refunding an order in thirds claws back more or fewer points than refunding it at once.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Input {earned, order_total, refunds:[cents], balance}. Cumulative refunds are capped at the order total. After each refund the cumulative clawback target is round-half-up(earned*cumulative refund/order total); the refund claws target minus already clawed. A clawback is taken from the balance only down to zero; the shortfall accumulates as debt. Return {claws, balance, debt}.

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
two partial refunds	`{"balance": 938, "claws": [31, 31], "debt": 0}`	`{"balance": 937, "claws": [31, 32], "debt": 0}`	Failed

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