/
index.js
29 lines (24 loc) · 1.17 KB
/
index.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
import toInteger from '../toInteger/index.js'
import toDate from '../../toDate/index.js'
// This function will be a part of public API when UTC function will be implemented.
// See issue: https://github.com/date-fns/date-fns/issues/376
export default function startOfUTCWeek (dirtyDate, dirtyOptions) {
if (arguments.length < 1) {
throw new TypeError('1 argument required, but only ' + arguments.length + ' present')
}
var options = dirtyOptions || {}
var locale = options.locale
var localeWeekStartsOn = locale && locale.options && locale.options.weekStartsOn
var defaultWeekStartsOn = localeWeekStartsOn == null ? 0 : toInteger(localeWeekStartsOn)
var weekStartsOn = options.weekStartsOn == null ? defaultWeekStartsOn : toInteger(options.weekStartsOn)
// Test if weekStartsOn is between 0 and 6 _and_ is not NaN
if (!(weekStartsOn >= 0 && weekStartsOn <= 6)) {
throw new RangeError('weekStartsOn must be between 0 and 6 inclusively')
}
var date = toDate(dirtyDate, options)
var day = date.getUTCDay()
var diff = (day < weekStartsOn ? 7 : 0) + day - weekStartsOn
date.setUTCDate(date.getUTCDate() - diff)
date.setUTCHours(0, 0, 0, 0)
return date
}