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 { addDays } from "./dates_add_days.ts";  ← from dates.add-days ^1.0.0 · built alongside by fune
import { addBusinessDays } from "./dates_add_business_days.ts";  ← from dates.add-business-days ^1.0.0 · built alongside by fune

/**
 * The retry dates for a payment that failed on `failedOn`. Each offset counts
 * from the failure date, not from the previous retry, in calendar days or in
 * working days.
 */
export function dunningSchedule(failedOn: string, retryOffsetsDays: readonly number[], businessDays: boolean, holidays: readonly string[]): readonly string[] {
  let previous = 0;
  for (const offset of retryOffsetsDays) {
    if (!Number.isInteger(offset) || offset < 1) {
      throw new RangeError(`retry offsets must be whole days of 1 or more, received ${offset}`);
    }
    if (offset <= previous) {
      throw new RangeError(`retry offsets must be strictly increasing, received ${offset} after ${previous}`);
    }
    previous = offset;
  }
  // Validates the failure date even for an empty policy.
  addDays(failedOn, 0);
  return retryOffsetsDays.map((offset) => (businessDays ? addBusinessDays(failedOn, offset, holidays) : addDays(failedOn, offset)));
}