@core / money

1.0.1 ▾

1.0.1

인증됨MIT

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정수(최소 단위) 금액: ISO 통화, 안전한 파싱, 반올림, 손실 없는 배분, .99 가격, 서식

코드파일 4개컨텍스트약 423토큰검사 통과

약 423토큰→ src/lib/money/AGENTS.md→ .cursor/rules/genpm-core-money.mdc

이것이 AI가 src/lib/money에서 작업할 때 읽는 내용 그대로입니다. 그 외에는 컨텍스트에 아무것도 추가되지 않습니다.

@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.

.genpmignore 적용 후 주입될 정확한 트리입니다. 고정 대상:

src/lib/money/index.ts읽기 전용 · e980a84

// @core/money — API pública. Importa desde aquí.
export {
  add,
  allocate,
  charmPrice,
  compare,
  convert,
  currencyDecimals,
  equals,
  format,
  isNegative,
  isZero,
  max,
  min,
  type Money,
  MoneyError,
  money,
  multiply,
  parseMoney,
  percent,
  sub,
  sum,
  toDecimalString,
  zero,
} from './money.ts';