@burglekitt/gmt/dist/internal/resolveDurationUnit.js

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

import { isValidDateTimeDurationUnit } from "../plain/validate/index.js";
/**
 * Normalize a duration unit string to its plural form.
 *
 * - Accepts singular ("day"), plural ("days"), and already-plural forms.
 * - Returns the original string if it is not a recognized DateTimeDurationUnit.
 *
 * @param unit raw unit string from caller input
 * @returns normalized plural unit string, or the original if not recognized
 */
export function resolveDurationUnit(unit) {
    if (isValidDateTimeDurationUnit(unit)) {
        return unit;
    }
    if (unit.endsWith("s")) {
        return unit;
    }
    const plural = `${unit}s`;
    if (isValidDateTimeDurationUnit(plural)) {
        return plural;
    }
    return unit;
}