Round Like the Currency Says

Round Like the Currency Says

A custom pricing feature computes invoice totals and unit prices in code, and a reviewer spotted the same 0.01 hardcoded in every rounding call. Finance does not round that way: Swiss francs are invoiced to the nearest 0.05, yen carry no decimals at all, and each of those rules lives on the Currency card — or, for the local currency, in General Ledger Setup. Code that ignores the setup prints totals no cashier can settle.

Your job is a small codeunit that rounds the way the currency says.

Requirements

Create a codeunit named "Currency Rounding" with two public procedures:

procedure RoundInvoiceTotal(Amount: Decimal; CurrencyCode: Code[10]): Decimal
procedure RoundUnitPrice(Amount: Decimal; CurrencyCode: Code[10]): Decimal

Rules:

1. RoundInvoiceTotal rounds Amount to a multiple of the currency's "Invoice Rounding Precision", in the direction its "Invoice Rounding Type" asks for — Nearest, Up or Down.
2. RoundUnitPrice rounds Amount to the nearest multiple of the currency's "Unit-Amount Rounding Precision". The invoice rounding type plays no part here: a currency that rounds invoices up still rounds unit prices to the nearest.
3. A blank CurrencyCode means the local currency (LCY), and the values then come from General Ledger Setup: "Inv. Rounding Precision (LCY)", "Inv. Rounding Type (LCY)" and "Unit-Amount Rounding Precision". The Currency record's Initialize procedure handles this branch for you — given a blank code, it fills the record's rounding fields from General Ledger Setup; given any other code, it reads that currency card — so your code can read the same fields either way.
4. Up and Down mean what the AL Round method means by its '>' and '<' directions, not what a calculator's ceiling and floor mean: '>' moves away from zero and '<' moves toward zero, for negative amounts too. A credit memo total of -10.01 in a currency that rounds up to 0.05 becomes -10.05, and -10.99 in a currency that rounds down to whole units becomes -10.
5. CurrencyCode is always blank or the code of a currency that exists, and every precision the tests configure is greater than zero. Neither procedure writes anything — they read setup and return a value.

Two things to know before you start:

• Round takes the direction as a text argument: '=' for nearest, '>' for up, '<' for down. Currency.InvoiceRoundingDirection() returns exactly that text for the record's "Invoice Rounding Type", so there is nothing to translate by hand.
• "Amount Rounding Precision" is a third, different field (it rounds line amounts). Reading it instead of the invoice or unit-amount precision fails both procedures. Likewise, re-implementing the rounding with your own division-and-ceiling arithmetic goes wrong on negative amounts — let Round do it.

Pick object IDs in the range 50100–50199, and reference other objects by name, never by ID.

Examples

What the tests check

The grading tests create three currencies of their own — one with an invoice rounding precision of 0.05 and type Up and a unit-amount precision of 0.001, another with 1.00 and type Down and a unit-amount precision of 0.1, and a third with 0.05 and type Nearest (checked with 10.02, which must become 10.00, and 10.03, which must become 10.05) — and set General Ledger Setup to an LCY invoice rounding precision of 0.25 with type Up and a unit-amount precision of 0.001. The "Amount Rounding Precision" is 0.01 on all of them, so a read of the wrong field shows up as a wrong number. Each procedure is called with the positive and negative amounts from the examples, with an amount that already sits on its precision (it must come back unchanged), with a generated amount, and with a blank currency code. Every comparison is an exact decimal equality.

Learn More

• System.Round method — the precision and direction parameters, with a table showing what '>' and '<' do to negative numbers.
• Set up invoice rounding — where the invoice rounding precision and type live for foreign currencies and for LCY.
• Set up currencies — the Currency card fields, and how unit-amount rounding differs from amount rounding.