FA-60708 / Loyalty points ledgers / Member archive

Birthday bonus window: once-per-year key · case 03

A member receives two bonuses for one birthday when purchases straddle New Year.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Input {bmonth, bday, window, bonus, purchases:[[y,m,d]] chronological}. The birthday of year Y is (Y,bmonth,bday), with Feb 29 falling back to Feb 28 in non-leap years (Gregorian rule). A purchase within window days (inclusive, either side) of the birthday of year Y-1, Y or Y+1 earns the bonus once per birthday year. Return per-purchase bonus list.

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
year crossing	`[300, 300]`	`[300, 0]`	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.