| 1 | /** Money is held in micros: millionths of a dollar. */ |
| 2 | export const MICROS_PER_DOLLAR = 1_000_000; |
| 3 | |
| 4 | const WHOLE = new Intl.NumberFormat("en-US", { style: "currency", currency: "USD", minimumFractionDigits: 2, maximumFractionDigits: 2 }); |
| 5 | const SMALL = new Intl.NumberFormat("en-US", { style: "currency", currency: "USD", minimumFractionDigits: 2, maximumFractionDigits: 4 }); |
| 6 | |
| 7 | /** |
| 8 | * Dollars, to the cent; amounts under a dollar keep up to four places, so |
| 9 | * a run that cost a fraction of a cent does not read as nothing. With |
| 10 | * `cents`, always to the cent: for statements, where figures sit in columns. |
| 11 | */ |
| 12 | export function usd(micros: number | null | undefined, { signed = false, cents = false }: { signed?: boolean; cents?: boolean } = {}): string { |
| 13 | if (micros == null) return "—"; |
| 14 | const dollars = micros / MICROS_PER_DOLLAR; |
| 15 | const text = (Math.abs(dollars) < 1 && !cents ? SMALL : WHOLE).format(Math.abs(dollars)); |
| 16 | if (dollars < 0) return `−${text}`; |
| 17 | return signed && dollars > 0 ? `+${text}` : text; |
| 18 | } |
| 19 | |
| 20 | /** |
| 21 | * Micros from a dollar amount as typed: `25`, `25.5`, `$1,250.00`. Null |
| 22 | * unless it is a non-negative amount to the cent, under ten million. |
| 23 | */ |
| 24 | export function parseDollars(input: string): number | null { |
| 25 | const text = input.trim().replace(/^\$/, "").replace(/,/g, ""); |
| 26 | const match = /^(\d{1,7})(?:\.(\d{1,2}))?$/.exec(text); |
| 27 | if (!match) return null; |
| 28 | const cents = Number((match[2] ?? "").padEnd(2, "0")); |
| 29 | return Number(match[1]) * MICROS_PER_DOLLAR + cents * 10_000; |
| 30 | } |
| 31 | |
| 32 | /** A micros amount as dollars for a form field: `1250.5` → `"1250.50"`. */ |
| 33 | export function dollarsField(micros: number | null | undefined): string { |
| 34 | return micros == null ? "" : (micros / MICROS_PER_DOLLAR).toFixed(2); |
| 35 | } |