FA-58068 / Double-entry ledger accounting / Member archive

Account running balance report: line ordering key · case 03

Back-dated entries appear at the end of the ledger with wrong running balances.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

x = {'normal': 'D'|'C', 'opening': balance before all lines, 'lines': [[seq, day, side, amount]], 'from': day, 'to': day}. Balances are signed positive on the normal side. The report opening is the opening plus every line dated before 'from'. Lines dated from..to inclusive are listed in (day, seq) order with the running balance after each; closing is the last running balance (the report opening if none). Return {'opening', 'rows': [[seq, day, running]], 'closing'}.

Why this case matters

Ledger software must keep debits equal to credits and apply normal-balance, period and cutoff rules exactly; small sign or boundary slips silently misstate financial statements.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression: line ordering key	`{"closing": -320, "opening": -20, "rows": [[2, 5, -145], [4, 3, -20], [5, 5, -320]]}`	`{"closing": -320, "opening": -20, "rows": [[4, 3, 105], [2, 5, -20], [5, 5, -320]]}`	Failed

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