@core / money

1.0.1 ▾

1.0.1

verificadoMIT

GitHub

Dinero en enteros (céntimos): monedas ISO, parseo seguro, redondeo, reparto sin pérdidas, precios .99 y formato

Código4 archivosContexto~423 tokensescaneo superado

Instalar

$genpm add @core/money

Qué obtienes

Código en src/lib/money/, 4 archivos. (9,6 kB)
Reglas de IA en src/lib/money/AGENTS.md, más archivos de reglas para tu IDE.
Resuelve @core/contracts por ti.

README

Este paquete no tiene README.

~423 tokens→ src/lib/money/AGENTS.md→ .cursor/rules/genpm-core-money.mdc

Esto es exactamente lo que lee tu IA cuando trabaja en src/lib/money. No se añade nada más a su contexto.

@core/money — rules for AI agents

Purpose

Money as { amount, currency } with amount an integer of minor units (cents) and an ISO 4217 code, so commerce modules never use floats. Parsing from decimal strings, safe arithmetic that refuses mixed currencies, rounding, percentages, lossless allocation (splitting a discount across lines), charm prices (.99, never below the input; …9 in zero-decimal currencies), formatting with Intl and conversion with a rates table. Pure functions: no tables, no network.

Map

index.ts — public API: money, parseMoney, add, sub, sum, multiply, percent, allocate, charmPrice, format, toDecimalString, convert, currencyDecimals.
money.ts — implementation. The Money type comes from @core/contracts.

Integration

Nothing to configure. Store money in two columns: amount integer (minor units) and currency text.
User input: parseMoney('19,99', 'EUR') (never Number(input) * 100).
Display: format(price, locale); APIs/JSON-LD: toDecimalString(price).
Split amounts: allocate(discount, lines.map((l) => l.subtotal.amount)).
Verify: add(money(1, 'EUR'), money(1, 'USD')) throws.

Conventions

All arithmetic through these helpers; JPY has 0 decimals and KWD 3, so never assume 100.
Percentages round half-up by default; pass 'half-even' where your accounting requires it.
Exchange rates are inputs (store the rate used with each order); this module does not fetch them.

Don't

Don't use floats for prices, totals or taxes, and don't add amounts of different currencies.
Don't round intermediate results before the final step unless the business rule says so.

# @core/money — rules for AI agents

## Purpose
Money as `{ amount, currency }` with `amount` an integer of minor units (cents) and an ISO 4217 code, so commerce
modules never use floats. Parsing from decimal strings, safe arithmetic that refuses mixed currencies, rounding,
percentages, lossless allocation (splitting a discount across lines), charm prices (`.99`, never below the input; `…9` in zero-decimal currencies), formatting with `Intl`
and conversion with a rates table. Pure functions: no tables, no network.

## Map
- `index.ts` — public API: `money`, `parseMoney`, `add`, `sub`, `sum`, `multiply`, `percent`, `allocate`, `charmPrice`, `format`, `toDecimalString`, `convert`, `currencyDecimals`.
- `money.ts` — implementation. The `Money` type comes from @core/contracts.

## Integration
1. Nothing to configure. Store money in two columns: `amount integer` (minor units) and `currency text`.
2. User input: `parseMoney('19,99', 'EUR')` (never `Number(input) * 100`).
3. Display: `format(price, locale)`; APIs/JSON-LD: `toDecimalString(price)`.
4. Split amounts: `allocate(discount, lines.map((l) => l.subtotal.amount))`.
5. Verify: `add(money(1, 'EUR'), money(1, 'USD'))` throws.

## Conventions
- All arithmetic through these helpers; JPY has 0 decimals and KWD 3, so never assume 100.
- Percentages round half-up by default; pass `'half-even'` where your accounting requires it.
- Exchange rates are inputs (store the rate used with each order); this module does not fetch them.

## Don't
- Don't use floats for prices, totals or taxes, and don't add amounts of different currencies.
- Don't round intermediate results before the final step unless the business rule says so.