@burglekitt/gmt/dist/plain/calculate/maxDate.js

Temporal-based date and time utilities with timezone support and polyfill integration

import { Temporal } from "@js-temporal/polyfill";
import { isValidDate } from "../validate/index.js";
/**
 * Return the latest (maximum) of the given PlainDate values.
 *
 * - Returns null if the array is empty or contains no valid dates.
 * - Validation is performed on each item in the array.
 *
 * @param dates Array of ISO PlainDate strings (e.g. "2024-03-10")
 * @returns The latest date string, or null on invalid input
 *
 * @example maxDate(["2024-03-10", "2024-03-15", "2024-03-12"]) // "2024-03-15"
 * @example maxDate([]) // null
 */
export function maxDate(dates) {
    if (!dates.length)
        return null;
    const valid = dates.filter(isValidDate);
    if (!valid.length)
        return null;
    try {
        const max = valid.reduce((currentMax, candidateStr) => {
            const candidate = Temporal.PlainDate.from(candidateStr);
            return Temporal.PlainDate.compare(candidate, currentMax) > 0
                ? candidate
                : currentMax;
        }, Temporal.PlainDate.from(valid[0]));
        return max.toString();
    }
    catch {
        return null;
    }
}