fluxer/packages/geo_utils/src/RegionCodeValidation.tsx
2026-02-17 12:22:36 +00:00

51 lines
1.5 KiB
TypeScript

/*
* Copyright (C) 2026 Fluxer Contributors
*
* This file is part of Fluxer.
*
* Fluxer is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Fluxer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
*/
const ASCII_UPPER_A = 65;
const ASCII_UPPER_Z = 90;
const REGION_CODE_LENGTH = 2;
function isAsciiUpperAlpha2(value: string): boolean {
return (
value.length === REGION_CODE_LENGTH &&
value.charCodeAt(0) >= ASCII_UPPER_A &&
value.charCodeAt(0) <= ASCII_UPPER_Z &&
value.charCodeAt(1) >= ASCII_UPPER_A &&
value.charCodeAt(1) <= ASCII_UPPER_Z
);
}
export function normalizeRegionCode(regionCode: string): string | undefined {
const trimmedRegionCode = regionCode.trim();
if (trimmedRegionCode.length !== REGION_CODE_LENGTH) {
return undefined;
}
const upperRegionCode = trimmedRegionCode.toUpperCase();
if (!isAsciiUpperAlpha2(upperRegionCode)) {
return undefined;
}
return upperRegionCode;
}
export function isRegionCode(value: string): boolean {
return normalizeRegionCode(value) !== undefined;
}