findCardBrand

v0.0.5

Detect a payment-card brand from a number's digits by its IIN/BIN pattern. Returns the brand whose pattern matches the most leading digits (so it narrows down as the user types), or undefined if none match. Pure.

Source

Example

findCardBrand('4111111111111111')?.brand; // 'visa'
findCardBrand('371449635398431')?.brand;   // 'american-express'
findCardBrand('2200123412341234')?.brand;  // 'mir'

Signature

declare function findCardBrand(digits: string, brands?: readonly CardBrand[]): CardBrand | undefined;

Parameters

Parameter	Type	Default	Description
`digits`	`string`	—	The card number's digits (no separators)
`brands`?	`readonly CardBrand[]`	—	The brand list

Returns

CardBrand | undefinedThe detected brand, or undefined

Related Types

CardBrand

One payment-card brand.

interface CardBrand

Property	Type	Default	Description
`brand`readonly	`string`	—	Brand id, e.g. `'visa'`.
`name`readonly	`string`	—	Display name, e.g. `'Visa'`.
`template`readonly	`string`	—	Number template; `#` is a digit, e.g. `'#### #### #### ####'`.
`lengths`readonly	`readonly number[]`	—	Valid total digit lengths, e.g. `[16, 18, 19]`.
`code`readonly	`{ readonly name: string; readonly size: number; }`	—	Security code metadata, e.g. `{ name: 'CVV', size: 3 }`.
`patterns`readonly	`readonly CardPattern[]`	—	IIN/BIN detection patterns (prefixes and ranges).

PhoneCountry

Phone-number formats for every country: an international template with the dialing-code digits as # digit placeholders, plus the priority/areaCodes used to disambiguate countries sharing a dialing code (NANP +1, +7 RU/KZ). NANP territories are normalized to code '1' (their 3-digit prefix moved into areaCodes), so every dialing code is prefix-free and the +1 block shares one numbering-plan template. Derived from the MIT-licensed react-phone-input-2 dataset — display formats, not authoritative validation.

interface PhoneCountry

Property	Type	Default	Description
`name`?readonly	`string`	—	Display name, e.g. `'United States'` (omit for custom lists).
`iso2`?readonly	`string`	—	ISO 3166-1 alpha-2 code, lowercase, e.g. `'us'` (omit for custom lists).
`code`readonly	`string`	—	International dialing code digits (no `+`), e.g. `'1'`, `'380'`.
`template`readonly	`string`	—	International template; `#` is a digit, e.g. `'+# (###) ###-####'`.
`priority`?readonly	`number`	—	Order among countries sharing `code` — lower wins when no area code matches. Absent means `0` (the primary country for that code).
`areaCodes`?readonly	`readonly string[]`	—	Area codes (the digits right after `code`) that belong to this country.

CardPattern

Payment-card brands: detection patterns (IIN/BIN prefixes and ranges), the number template (# = a digit), valid total lengths, and the security-code info. Derived from the MIT-licensed credit-card-type dataset (Braintree). The template uses the brand's gap positions; the trailing group is sized to the longest valid length, so shorter numbers simply leave it partly empty.

type CardPattern = string | readonly [min: number, max: number];

CookieAttributes

Write-time cookie attributes (the Set-Cookie half of RFC 6265). Cookies expose no way to read attributes back — these only describe how a cookie is written (and must be repeated to overwrite or delete it, since a cookie's identity is its name + domain + path).

interface CookieAttributes

Property	Type	Default	Description
`path`?	`string`	`'/'`	The path the cookie is scoped to.
`domain`?	`string`	—	The domain the cookie is scoped to. Omitted = host-only cookie.
`maxAge`?	`number`	—	Lifetime in seconds. Takes precedence over `expires` in browsers when both are present (RFC 6265 §4.1.2.2). Non-positive values expire the cookie.
`expires`?	`Date \| number`	—	Expiry as a `Date` or Unix epoch milliseconds. Omitting both `maxAge` and `expires` creates a session cookie.
`secure`?	`boolean`	—	Only send the cookie over HTTPS.
`sameSite`?	`'lax' \| 'strict' \| 'none'`	`'lax'`	`SameSite` attribute. `'none'` requires `secure: true` — browsers silently drop the cookie otherwise, so `serializeCookie` fails loudly instead.
`partitioned`?	`boolean`	`false`	Partition the cookie by top-level site (CHIPS). Requires `secure: true`.

InputState

The editable state of a text field: its current text and selection bounds. Framework-agnostic and structurally compatible with any { value, selection } pair (e.g. an input-masking engine's element state).

interface InputState

Property	Type	Default	Description
`value`readonly	`string`	—	The element's current `value`.
`selection`readonly	`readonly [from: number, to: number]`	—	The selection as `[from, to]` (collapsed caret when `from === to`).

StylePatch

A patch of inline styles — a map of CSS property names to string values. Keys may be camelCase DOM style properties (borderRadius) or --custom properties (set verbatim via setProperty).

type StylePatch = Record<string, string>;

TranslateAxis

The axis a translation is read along: x (horizontal) or y (vertical).

type TranslateAxis = 'x' | 'y';

TextFieldElement

A text field whose value and selection can be read and written.

type TextFieldElement = HTMLInputElement | HTMLTextAreaElement;