mask, unmask, isComplete

Pure functions: they work without the DOM — in the browser, on the server, in tests. The mask can be an object or a pattern string.

Signature

function mask(value: string, mask: MaskInput): string
function unmask(value: string, mask: MaskInput): string
function isComplete(value: string, mask: MaskInput): boolean
function isValid(value: string, mask: MaskInput): boolean

Function	Returns
mask	The formatted value
unmask	The unmasked value — for data and the database
isComplete	Whether all required positions are filled
isValid	Filled and correct: the date exists, the checksum matches — see Ready-made masks

null and undefined count as an empty string.

Examples

import { mask, unmask, isComplete } from 'tinyval-mask';
import { phone } from 'tinyval-mask/presets';

mask('89991234567', phone());          // '+7 (999) 123-45-67'
unmask('+7 (999) 123-45-67', phone()); // '79991234567'
isComplete('+7 (999) 123', phone());   // false
isValid('4111 1111 1111 1112', card()); // false — wrong check digit

mask('20261002', '9999-99-99');        // '2026-10-02'

// server: normalize phones from any source
const normalized = users.map((u) => ({ ...u, phone: unmask(u.phone, phone()) }));
// '8 (999) 123-45-67', '+7 999 1234567', '9991234567' → '79991234567'

See also

• Masks & validation
• attach — a mask on an input field