Credit Card Validator

This project provides a simple implementation to validate credit card numbers and identify their brands using the Luhn algorithm and regular expressions.

Features

• Validation: Ensures the credit card number is valid using the Luhn algorithm.
• Brand Identification: Identifies the card brand based on the BIN (Bank Identification Number) using regex patterns.
• Supported Brands:
  • Visa
  • Mastercard
  • American Express
  • Diners
  • Elo
  • Aura
  • Hipercard

How It Works

1. Validation:

   • The isValidCardNumber function checks if the credit card number is valid using the Luhn algorithm.
   • It calculates a checksum by doubling every second digit from the right and summing all digits. If the total is divisible by 10, the card number is valid.

2. Brand Identification:

   • The identifyBrand function uses a list of regex patterns to match the BIN or card number to a specific brand.

Code Overview

Functions

• validateCard(cardNumber):

  • Validates the card number and identifies the brand.
  • Returns the brand name or an error message.

• isValidCardNumber(cardNumber):

  • Implements the Luhn algorithm to validate the card number.
  • Returns true if valid, false otherwise.

• identifyBrand(cardNumber):

  • Matches the card number against regex patterns to identify the brand.
  • Returns the brand name or null if no match is found.

Example Usage

const cardNumber = "4389351234567890"; // Replace with a valid card number
const result = validateCard(cardNumber);
console.log(result); // Outputs the card brand or an error message

Supported BIN Patterns

Brand	BIN Pattern
Visa	Starts with 4
Mastercard	Starts with numbers between 51 and 55
American Express	Starts with 34 or 37
Diners	Starts with 301, 305, 36, or 38
Elo	Matches specific BINs like 636368, 438935
Aura	Starts with 50
Hipercard	Starts with 38 or 60

How to Run

1. Clone the repository to your local machine.
2. Ensure you have Node.js installed.
3. Run the script using the following command:

   node src/index.js

License

This project is open-source and available under the MIT License.