hugoWebsite/node_modules/date-fns/esm/setISOWeekYear/index.js

39 lines
1.5 KiB
JavaScript

import toInteger from "../_lib/toInteger/index.js";
import toDate from "../toDate/index.js";
import startOfISOWeekYear from "../startOfISOWeekYear/index.js";
import differenceInCalendarDays from "../differenceInCalendarDays/index.js";
import requiredArgs from "../_lib/requiredArgs/index.js";
/**
* @name setISOWeekYear
* @category ISO Week-Numbering Year Helpers
* @summary Set the ISO week-numbering year to the given date.
*
* @description
* Set the ISO week-numbering year to the given date,
* saving the week number and the weekday number.
*
* ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
*
* @param {Date|Number} date - the date to be changed
* @param {Number} isoWeekYear - the ISO week-numbering year of the new date
* @returns {Date} the new date with the ISO week-numbering year set
* @throws {TypeError} 2 arguments required
*
* @example
* // Set ISO week-numbering year 2007 to 29 December 2008:
* const result = setISOWeekYear(new Date(2008, 11, 29), 2007)
* //=> Mon Jan 01 2007 00:00:00
*/
export default function setISOWeekYear(dirtyDate, dirtyISOWeekYear) {
requiredArgs(2, arguments);
var date = toDate(dirtyDate);
var isoWeekYear = toInteger(dirtyISOWeekYear);
var diff = differenceInCalendarDays(date, startOfISOWeekYear(date));
var fourthOfJanuary = new Date(0);
fourthOfJanuary.setFullYear(isoWeekYear, 0, 4);
fourthOfJanuary.setHours(0, 0, 0, 0);
date = startOfISOWeekYear(fourthOfJanuary);
date.setDate(date.getDate() + diff);
return date;
}