Credit Card Type

import creditCardType from "credit-card-type";

const creditCardType = require("credit-card-type");

import creditCardType from "credit-card-type";

// Detect from partial number (type-as-you-go)
const partialResults = creditCardType("4111");
console.log(partialResults[0].type); // 'visa'
console.log(partialResults[0].niceType); // 'Visa'

// Multiple matches with ambiguous input
const ambiguousResults = creditCardType("6");
console.log(ambiguousResults.length); // 6 (multiple card types start with 6)
console.log(ambiguousResults[0].niceType); // 'Discover'
console.log(ambiguousResults[1].niceType); // 'UnionPay'

// Complete number detection
const completeResults = creditCardType("4111111111111111");
console.log(completeResults[0].gaps); // [4, 8, 12] - formatting positions
console.log(completeResults[0].lengths); // [16, 18, 19] - valid lengths
console.log(completeResults[0].code); // { name: 'CVV', size: 3 }

/**
 * Determines credit card types from a card number string
 * @param cardNumber - Card number string (should be normalized, no spaces/letters)
 * @returns Array of matching card types, empty array if no matches
 */
function creditCardType(cardNumber: string): Array<CreditCardType>;

/**
 * Returns card configuration for a specific card type
 * @param cardType - Card type identifier (e.g., 'visa', 'mastercard')
 * @returns Card configuration object or undefined if invalid type
 */
function getTypeInfo(cardType: string): CreditCardType | undefined;

/**
 * Adds a custom card type to the detection system
 * @param config - Card configuration object
 */
function addCard(config: CreditCardType): void;

/**
 * Removes a card type from detection
 * @param name - Card type name to remove
 */
function removeCard(name: string): void;

/**
 * Updates an existing card type configuration
 * @param cardType - Card type identifier to update
 * @param updates - Partial configuration object with updates
 */
function updateCard(cardType: string, updates: Partial<CreditCardType>): void;

/**
 * Changes the priority order for card type detection
 * @param name - Card type name to reorder
 * @param position - New position in the detection order (0-based)
 */
function changeOrder(name: string, position: number): void;

/**
 * Resets all custom modifications to original state
 */
function resetModifications(): void;

const types: {
  VISA: "visa";
  MASTERCARD: "mastercard";
  AMERICAN_EXPRESS: "american-express";
  DINERS_CLUB: "diners-club";
  DISCOVER: "discover";
  JCB: "jcb";
  UNIONPAY: "unionpay";
  VERVE: "verve";
  MAESTRO: "maestro";
  ELO: "elo";
  MIR: "mir";
  HIPER: "hiper";
  HIPERCARD: "hipercard";
};

interface CreditCardType {
  /** Human-readable card brand name (e.g., "Visa", "Mastercard") */
  niceType: string;
  /** Code-friendly card type identifier (e.g., "visa", "mastercard") */
  type: string;
  /** Number patterns for matching: single numbers, ranges [min, max], or mixed arrays */
  patterns: (number | [number, number])[];
  /** Expected gap positions for formatting (e.g., [4, 8, 12] for "1234 5678 9012 3456") */
  gaps: number[];
  /** Valid card number lengths (excluding spaces) */
  lengths: number[];
  /** Security code information */
  code: {
    /** Security code name (e.g., "CVV", "CVC", "CID") */
    name: string;
    /** Security code length (3 or 4 digits) */
    size: number;
  };
  /** Pattern matching strength (set internally during detection) */
  matchStrength?: number;
}

type CreditCardTypeCardBrandId =
  | "american-express"
  | "diners-club"
  | "discover"
  | "elo"
  | "hiper"
  | "hipercard"
  | "jcb"
  | "verve"
  | "maestro"
  | "mastercard"
  | "mir"
  | "unionpay"
  | "visa";

import creditCardType from "credit-card-type";

// Add a custom card type
creditCardType.addCard({
  niceType: "Custom Bank Card",
  type: "custom-card",
  patterns: [9999, [8888, 8889]],
  gaps: [4, 8, 12],
  lengths: [16],
  code: {
    name: "CVV",
    size: 3,
  },
});

// Update existing card type
creditCardType.updateCard(creditCardType.types.VISA, {
  niceType: "Visa Custom",
  lengths: [13, 16, 19], // Add support for old 13-digit Visas
});

// Change detection priority
creditCardType.changeOrder("custom-card", 0); // Highest priority

// Reset all modifications
creditCardType.resetModifications();

import creditCardType from "credit-card-type";

function formatCardNumber(cardNumber: string, cardType?: string): string {
  if (!cardType) {
    const results = creditCardType(cardNumber);
    if (results.length === 0) return cardNumber;
    cardType = results[0].type;
  }

  const typeInfo = creditCardType.getTypeInfo(cardType);
  if (!typeInfo) return cardNumber;

  const { gaps } = typeInfo;
  const offsets = [0, ...gaps, cardNumber.length];
  const components = [];

  for (let i = 0; offsets[i] < cardNumber.length; i++) {
    const start = offsets[i];
    const end = Math.min(offsets[i + 1], cardNumber.length);
    components.push(cardNumber.substring(start, end));
  }

  return components.join(" ");
}

// Usage
formatCardNumber("4111111111111111", "visa"); // "4111 1111 1111 1111"
formatCardNumber("378282246310005", "american-express"); // "3782 822463 10005"

import creditCardType from "credit-card-type";

// Only allow specific card types
const allowedTypes = [creditCardType.types.VISA, creditCardType.types.MASTERCARD];

function getAcceptedCardTypes(cardNumber: string) {
  return creditCardType(cardNumber).filter((card) =>
    allowedTypes.includes(card.type as any)
  );
}