@burglekitt/gmt/dist/plain/interval/validate/isValidTimeInterval.js

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

import { Temporal } from "@js-temporal/polyfill";
import { plainTime } from "../../../regex/index.js";
/**
 * Return true if `start` and `end` form a valid time interval — both parseable as
 * ISO PlainTime strings and `start <= end`.
 *
 * - Both inputs must be ISO 8601 time strings (e.g. `"14:30:00"`).
 * - Equal `start === end` is valid.
 * - Invalid input, malformed strings, or leap-second strings return `false`.
 *
 * @param start ISO 8601 time string (interval start)
 * @param end ISO 8601 time string (interval end)
 * @returns true if start and end form a valid time interval, or false on invalid input
 *
 * @example isValidTimeInterval("09:00:00", "17:00:00") // true
 * @example isValidTimeInterval("12:00:00", "12:00:00") // true
 * @example isValidTimeInterval("17:00:00", "09:00:00") // false
 * @example isValidTimeInterval("invalid", "12:00:00") // false
 */
export function isValidTimeInterval(start, end) {
    if (typeof start !== "string" || typeof end !== "string") {
        return false;
    }
    if (!plainTime.test(start) || !plainTime.test(end)) {
        return false;
    }
    try {
        const t1 = Temporal.PlainTime.from(start);
        const t2 = Temporal.PlainTime.from(end);
        const isLessThan = t1.hour < t2.hour ||
            (t1.hour === t2.hour && t1.minute < t2.minute) ||
            (t1.hour === t2.hour &&
                t1.minute === t2.minute &&
                t1.second < t2.second) ||
            (t1.hour === t2.hour &&
                t1.minute === t2.minute &&
                t1.second === t2.second &&
                t1.millisecond < t2.millisecond);
        const isEqual = t1.hour === t2.hour &&
            t1.minute === t2.minute &&
            t1.second === t2.second &&
            t1.millisecond === t2.millisecond;
        return isLessThan || isEqual;
    }
    catch {
        return false;
    }
}