setDay.js
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"use strict";
exports.setDay = setDay;
var _index = require("./addDays.js");
var _index2 = require("./toDate.js");
var _index3 = require("./_lib/defaultOptions.js");
/**
* The {@link setDay} function options.
*/
/**
* @name setDay
* @category Weekday Helpers
* @summary Set the day of the week to the given date.
*
* @description
* Set the day of the week to the given date.
*
* @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
*
* @param date - The date to be changed
* @param day - The day of the week of the new date
* @param options - An object with options.
*
* @returns The new date with the day of the week set
*
* @example
* // Set week day to Sunday, with the default weekStartsOn of Sunday:
* const result = setDay(new Date(2014, 8, 1), 0)
* //=> Sun Aug 31 2014 00:00:00
*
* @example
* // Set week day to Sunday, with a weekStartsOn of Monday:
* const result = setDay(new Date(2014, 8, 1), 0, { weekStartsOn: 1 })
* //=> Sun Sep 07 2014 00:00:00
*/
function setDay(date, day, options) {
const defaultOptions = (0, _index3.getDefaultOptions)();
const weekStartsOn =
options?.weekStartsOn ??
options?.locale?.options?.weekStartsOn ??
defaultOptions.weekStartsOn ??
defaultOptions.locale?.options?.weekStartsOn ??
0;
const _date = (0, _index2.toDate)(date);
const currentDay = _date.getDay();
const remainder = day % 7;
const dayIndex = (remainder + 7) % 7;
const delta = 7 - weekStartsOn;
const diff =
day < 0 || day > 6
? day - ((currentDay + delta) % 7)
: ((dayIndex + delta) % 7) - ((currentDay + delta) % 7);
return (0, _index.addDays)(_date, diff);
}