FA-60515 / Loyalty points ledgers / Member archive

Member-to-member point transfers: fee rounding direction · case 05

Transfer fees come out a point short on amounts that do not divide evenly.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Input {members:{id:balance}, transfers:[[from,to,pts]], fee_bp, min_transfer, annual_cap, sent_ytd}. Self transfers or unknown members are "invalid"; pts below the minimum are "below minimum"; sent_ytd + pts above annual_cap is "cap" (fees do not count toward the cap). The fee is ceil(pts*fee_bp/10000) points charged to the sender, who must hold pts + fee ("insufficient" otherwise). The recipient receives pts. Return {results (fee or reason), balances:[[id,bal]] sorted}.

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
normal transfer	`{"balances": [["a", 2946], ["b", 2104]], "results": [50]}`	`{"balances": [["a", 2945], ["b", 2104]], "results": [51]}`	Failed

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