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

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

import { Temporal } from "@js-temporal/polyfill";
import { addDateUnit, getStartOfDateUnit, } from "../../internal/dateUnitHelpers.js";
import { isValidDate, isValidDateUnit } from "../validate/index.js";
/**
 * Round an ISO 8601 date string to the specified date unit.
 *
 * - Returns "" for invalid inputs.
 * - Accepts date units: "year", "month", "week", "day".
 * - Time units ("hour", "minute", etc.) are rejected and return "".
 * - All date units use manual start-of-unit rounding.
 * - Wraps all Temporal calls in try-catch; returns "" on any error.
 *
 * @param value ISO 8601 date string
 * @param options Rounding options: smallestUnit, optional roundingIncrement and roundingMode
 * @returns Rounded ISO 8601 date string, or "" on invalid input
 *
 * @example roundDate("2024-06-15", { smallestUnit: "year" }) // "2024-01-01"
 * @example roundDate("2024-06-15", { smallestUnit: "month" }) // "2024-07-01"
 * @example roundDate("2024-06-15", { smallestUnit: "week" }) // "2024-06-16"
 * @example roundDate("2024-06-15", { smallestUnit: "day" }) // "2024-06-15"
 * @example roundDate("invalid", { smallestUnit: "year" }) // ""
 */
export function roundDate(value, options) {
    const { smallestUnit, roundingIncrement, roundingMode } = options;
    if (!isValidDate(value) || !isValidDateUnit(smallestUnit))
        return "";
    try {
        const source = Temporal.PlainDate.from(value);
        // Manual rounding for all date units (year, month, week, day)
        const startOfCurrent = getStartOfDateUnit(source, smallestUnit);
        const increment = roundingIncrement ?? 1;
        if (increment <= 0)
            return "";
        const startOfNext = addDateUnit(startOfCurrent, smallestUnit, increment);
        const elapsed = source.since(startOfCurrent);
        const total = startOfNext.since(startOfCurrent);
        const fraction = elapsed.total("days") / total.total("days");
        let rounded;
        const mode = roundingMode ?? "halfExpand";
        switch (mode) {
            case "ceil":
            case "expand":
                rounded =
                    Temporal.PlainDate.compare(source, startOfCurrent) > 0
                        ? startOfNext
                        : startOfCurrent;
                break;
            case "floor":
            case "trunc":
                rounded = startOfCurrent;
                break;
            case "halfExpand":
            case "halfCeil":
                rounded = fraction >= 0.5 ? startOfNext : startOfCurrent;
                break;
            case "halfTrunc":
            case "halfFloor":
                rounded = fraction > 0.5 ? startOfNext : startOfCurrent;
                break;
            case "halfEven":
                // Simplified: use halfExpand behavior
                rounded = fraction >= 0.5 ? startOfNext : startOfCurrent;
                break;
            default:
                rounded = startOfCurrent;
        }
        return rounded.toString();
    }
    catch {
        return "";
    }
}