@burglekitt/gmt/dist/utc/calculate/minUtc.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 earliest (minimum) of the given UTC datetime values.
 *
 * - Filters invalid values before finding minimum using Temporal.Instant.compare.
 * - 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 earliest UTC datetime string, or null on invalid input
 *
 * @example minUtc(["2024-03-10T12:00:00Z", "2024-03-15T12:00:00Z", "2024-03-12T12:00:00Z"]) // "2024-03-10T12:00:00Z"
 * @example minUtc(["invalid", "2024-03-15T12:00:00Z"]) // "2024-03-15T12:00:00Z"
 * @example minUtc(["invalid", "also invalid"]) // null
 * @example minUtc([]) // null
 */
export function minUtc(utcDateTimes) {
    if (!utcDateTimes.length)
        return null;
    const valid = utcDateTimes.filter(isValidUtc);
    if (!valid.length)
        return null;
    try {
        const min = valid.reduce((currentMin, candidateStr) => {
            const candidate = Temporal.Instant.from(candidateStr);
            return Temporal.Instant.compare(candidate, currentMin) < 0
                ? candidate
                : currentMin;
        }, Temporal.Instant.from(valid[0]));
        return min.toString();
    }
    catch {
        return null;
    }
}