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

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

import { Temporal } from "@js-temporal/polyfill";
import { isValidDateTime } from "../validate/index.js";
/**
 * Return the earliest (minimum) of the given PlainDateTime values.
 *
 * - Returns null if the array is empty or contains no valid datetimes.
 * - Validation is performed on each item in the array.
 *
 * @param dateTimes Array of ISO PlainDateTime strings (e.g. "2024-03-10T12:00:00")
 * @returns The earliest datetime string, or null on invalid input
 *
 * @example minDateTime(["2024-03-10T12:00:00", "2024-03-15T12:00:00", "2024-03-12T12:00:00"]) // "2024-03-10T12:00:00"
 * @example minDateTime([]) // null
 */
export function minDateTime(dateTimes) {
    if (!dateTimes.length)
        return null;
    const valid = dateTimes.filter(isValidDateTime);
    if (!valid.length)
        return null;
    try {
        const min = valid.reduce((currentMin, candidateStr) => {
            const candidate = Temporal.PlainDateTime.from(candidateStr);
            return Temporal.PlainDateTime.compare(candidate, currentMin) < 0
                ? candidate
                : currentMin;
        }, Temporal.PlainDateTime.from(valid[0]));
        return min.toString();
    }
    catch {
        return null;
    }
}