tilfluktsrom/pwa/node_modules/es-abstract/2018/TimeZoneString.js
Ole-Morten Duesund e8428de775 Add progressive web app companion for cross-platform access
Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-08 17:41:38 +01:00

33 lines
1.6 KiB
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $Date = GetIntrinsic('%Date%');
var $TypeError = require('es-errors/type');
var isNaN = require('math-intrinsics/isNaN');
var callBound = require('call-bound');
var $indexOf = callBound('String.prototype.indexOf');
var $slice = callBound('String.prototype.slice');
var $toTimeString = callBound('Date.prototype.toTimeString');
// https://262.ecma-international.org/9.0/#sec-timezoneestring
module.exports = function TimeZoneString(tv) {
if (typeof tv !== 'number' || isNaN(tv)) {
throw new $TypeError('Assertion failed: `tv` must be a non-NaN Number'); // steps 1 - 2
}
// 3. Let offset be LocalTZA(tv, true).
// 4. If offset ≥ 0, let offsetSign be "+"; otherwise, let offsetSign be "-".
// 5. Let offsetMin be the String representation of MinFromTime(abs(offset)), formatted as a two-digit decimal number, padded to the left with a zero if necessary.
// 6. Let offsetHour be the String representation of HourFromTime(abs(offset)), formatted as a two-digit decimal number, padded to the left with a zero if necessary.
// 7. Let tzName be an implementation-defined string that is either the empty string or the string-concatenation of the code unit 0x0020 (SPACE), the code unit 0x0028 (LEFT PARENTHESIS), an implementation-dependent timezone name, and the code unit 0x0029 (RIGHT PARENTHESIS).
// 8. Return the string-concatenation of offsetSign, offsetHour, offsetMin, and tzName.
// hack until LocalTZA, and "implementation-defined string" are available
var ts = $toTimeString(new $Date(tv));
return $slice(ts, $indexOf(ts, '(') + 1, $indexOf(ts, ')'));
};