Standalone Type Guards

bn-calendar/utils provides the following type guards:

isBanglaYear()

function isBanglaYear(value: unknown): value is BanglaYear

Checks whether a value is a valid Bangla year in Bangla digits (০-৯৯৯৯).

import { isBanglaYear } from 'bn-calendar/utils';

isBanglaYear('১৪৩০'); // true
isBanglaYear('১০০০০'); // false (too long)
isBanglaYear('1430');  // false (Latin digits)

isBanglaMonth()

function isBanglaMonth(value: unknown): value is BanglaMonth

Checks whether a value is a valid Bangla month string in Bangla digits (১-১২).

import { isBanglaMonth } from 'bn-calendar/utils';

isBanglaMonth('১');  // true
isBanglaMonth('১২'); // true
isBanglaMonth('১৩'); // false

isBanglaDate()

function isBanglaDate(value: unknown): value is BanglaDate

Checks whether a value is a valid day of month in Bangla digits (১-৩১).

import { isBanglaDate } from 'bn-calendar/utils';

isBanglaDate('১');   // true
isBanglaDate('৩১');  // true
isBanglaDate('৩২');  // false

isBanglaDateString()

function isBanglaDateString(value: unknown): value is string

Checks whether a string is a valid Bangla date formatted as YYYY-MM-DD using Bangla digits and supported separators.

Note

Supported separators are -, /, _, ., and space ().

import { isBanglaDateString } from 'bn-calendar/utils';

isBanglaDateString('১৪৩০-০১-০১'); // true
isBanglaDateString('১৪৩০/১/১'); // true (single-digit month/date)
isBanglaDateString('1430-01-01'); // false (Latin digits)
isBanglaDateString('১৪৩০-১৩-০১'); // false (invalid month)