@burglekitt/gmt/dist/utc/calculate/maxUtc.js

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

import { Temporal } from "@js-temporal/polyfill";
import { isValidUtc } from "../validate/isValidUtc.js";
/**
 * Return the latest (maximum) of the given UTC datetime values.
 *
 * - Filters invalid values before finding maximum.
 * - Returns null if array is empty or has no valid values.
 *
 * @param utcDateTimes Array of ISO datetime strings (e.g. "2024-03-10T12:00:00Z")
 * @returns The latest UTC datetime string, or null on invalid input
 *
 * @example maxUtc(["2024-03-10T12:00:00Z", "2024-03-15T12:00:00Z", "2024-03-12T12:00:00Z"]) // "2024-03-15T12:00:00Z"
 * @example maxUtc(["invalid", "2024-03-15T12:00:00Z"]) // "2024-03-15T12:00:00Z"
 * @example maxUtc(["invalid", "also invalid"]) // null
 * @example maxUtc([]) // null
 */
export function maxUtc(utcDateTimes) {
    if (!utcDateTimes.length)
        return null;
    const valid = utcDateTimes.filter(isValidUtc);
    if (!valid.length)
        return null;
    try {
        const max = valid.reduce((currentMax, candidateStr) => {
            const candidate = Temporal.Instant.from(candidateStr);
            return Temporal.Instant.compare(candidate, currentMax) > 0
                ? candidate
                : currentMax;
        }, Temporal.Instant.from(valid[0]));
        return max.toString();
    }
    catch {
        return null;
    }
}