FA-58274 / Double-entry ledger accounting / Member archive

Receivables subledger tie-out: open customer count · case 04

Customers with credit balances are not counted as open.

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Case contract

x = {'control': [[day, amount]], 'sub': {customer: [[day, amount]]}, 'as_of': day}. Only rows dated on or before as_of count. The subledger total nets every customer balance, including credit (negative) balances. Return {'control', 'subledger', 'difference': control - subledger, 'credit_balances': customers with negative balance sorted by name, 'open_customers': count of nonzero balances}.

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: open customer count	`{"control": 120, "credit_balances": ["acme"], "difference": 420, "open_customers": 0, "subledger": -300}`	`{"control": 120, "credit_balances": ["acme"], "difference": 420, "open_customers": 1, "subledger": -300}`	Failed

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