impl/typescript.ts

Imports name this capability’s declared dependencies, which fune builds next to it in your project; each one links to its page.

import { type Money, money } from "./money_amount.ts";  ← from money.amount ^1.0.0 · built alongside by fune
import { type RetainerApplication, type RetainerBill, type RetainerDrawdown } from "./legal_retainer_drawdown_types.ts";

/** Apply money on account to bills in the order given. */
export function retainerDrawdown(onAccount: Money, bills: readonly RetainerBill[]): RetainerDrawdown {
  const currency = onAccount.currency;
  if (onAccount.minor < 0) {
    throw new RangeError(`onAccount must not be negative, received ${onAccount.minor}`);
  }
  let left = onAccount.minor;
  let applied = 0;
  let outstanding = 0;
  const lines: RetainerApplication[] = [];
  for (const bill of bills) {
    if (bill.amount.currency !== currency) {
      throw new RangeError(`currency mismatch: ${currency} and ${bill.amount.currency}`);
    }
    if (bill.amount.minor < 0) {
      throw new RangeError(`bill "${bill.reference}" must not be negative, received ${bill.amount.minor}`);
    }
    const take = Math.min(left, bill.amount.minor);
    left -= take;
    applied += take;
    outstanding += bill.amount.minor - take;
    lines.push({ reference: bill.reference, billed: bill.amount, applied: money(take, currency), outstanding: money(bill.amount.minor - take, currency) });
  }
  return { bills: lines, applied: money(applied, currency), outstanding: money(outstanding, currency), balance: money(left, currency) };
}