cadrumo.core.money.rounding module

Canonical Decimal money primitives.

Single authoritative implementation of the half-up euro-cent rounding convention used across every AEAT calculation surface (LIRPF art. 23.1 rental net income, IRPF deductions, IVA prorata, asset depreciation, inventory cost basis). Callers in cadrumo.domain.* import round_to_cents() and the CENT quantum from here rather than reimplementing the quantize call.

The half-up rounding mode (ROUND_HALF_UP) matches the AEAT publication convention: a residual cent of exactly 0.5 rounds away from zero. Python’s default banker’s rounding (ROUND_HALF_EVEN) does NOT match AEAT and must never be used at the euro-cent boundary for any operator-facing or filed value.

round_to_cents(value)

Round value to euro-cent precision with half-up semantics.

Parameters:

value (Decimal) – The Decimal amount to round.

Return type:

Decimal

Returns:

A Decimal quantised to two fractional digits using decimal.ROUND_HALF_UP.

Raises:

InvalidOperation – When quantising value to two fractional digits would exceed the active decimal context’s precision — from 27 integral digits under the default 28-digit context. Callers reachable from operator input must refuse an out-of-range magnitude at their own boundary rather than let this escape: this function is crossed long before the AEAT export encoder, so it, not the encoder, is the first boundary an unbounded figure meets.