CardValidator

• Description
• Installation
• Usage
  • Creating a CreditCard object
  • Checking card number validity
  • Validation Helper Methods
  • CardFactory generator
• Changelog

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Description

CardValidator is a performant NuGet package that provides a credit card validator based on the card number. It focuses on checking the number length and numeric prefixes according to the issuer (such as AmericanExpress, ChinaUnionPay, Dankort, DinersClub, Discover, Hipercard, JCB, Laser, Maestro, MasterCard, RuPay, Switch, Visa). For each respective issuer, it also checks if the card number is valid according to the Luhn algorithm. The package is designed to prioritize performance.

Installation

You can install the CardValidator NuGet package via the NuGet Package Manager or by using the following command in the Package Manager Console:

Install-Package CardValidator

Usage

Creating a CreditCard object

You can create a CreditCard object by providing a card number as a string or a ReadOnlySpan<char>.

// Example 1: Creating a CreditCard object from a string
string visaCardNumber = "4205 2245 9865 9069";
CreditCard visaCard = new CreditCard(visaCardNumber);
Console.WriteLine(visaCard);

// Example 2: Creating a CreditCard object from a ReadOnlySpan<char>
ReadOnlySpan<char> americanExpressCardNumberSpan = "347554301215479".AsSpan();
CreditCard amExCard = new CreditCard(americanExpressCardNumberSpan);
Console.WriteLine(amExCard);

// Example 3: Creating a CreditCard object without length check
string americanExpressCardLonger = "3475543012154790";
CreditCard amExCard2 = new CreditCard(americanExpressCardLonger, true);
Console.WriteLine(amExCard2);

Checking card number validity

You can check the validity of a card number using the IsValid method of the CreditCard object.

// Example 4: Checking validity for a specific issuer
Console.WriteLine(visaCard.IsValid(CardIssuer.Visa));
// ---> True

// Example 5: Checking validity for multiple issuers
Console.WriteLine(visaCard.IsValid(CardIssuer.Visa, CardIssuer.MasterCard));
// ---> True

// Example 6: Checking validity for an unsupported issuer
Console.WriteLine(visaCard.IsValid(CardIssuer.MasterCard));
// ---> False

Validation Helper Methods

The ValidationHelper class provides additional helper methods for card number validation.

// Example 7: Checking if a card number is valid based on issuer
ReadOnlySpan<char> cardNumber = "4111111111111111".AsSpan();
bool isValid = ValidationHelper.IsValidNumber(cardNumber, CardIssuer.Visa);
Console.WriteLine(isValid);
// ---> True

// Example 8: Checking if a card number is valid by ValidationHelper
bool isValid = ValidationHelper.IsValidFormat("4111111111111111");
Console.WriteLine(isValid);
// ---> True

CardFactory generator

The CardFactory class provides method generating valid card number.

// Example: Generating a random card number for a specific issuer
string randomCardNumber = CardFactory.GenerateRandomCardNumber(CardIssuer.Visa); 
Console.WriteLine(randomCardNumber); 
// ---> Randomly generated card number for the specified issuer

Changelog

• 1.3.0
  • Added CardFactory to generate valid random card numbers
• 1.2.0
  • Added validation helper methods (IsValidNumber, IsValidFormat)
• 1.1.1
  • Fixed MasterCard specification
  • Added demo examples
• 1.1.0
  • Performance enhancements:
    • Improved performance of the IsValid(params CardIssuer[] issuers) method, making it 5.5x faster and reducing memory allocation compared to version 1.0.0
    • Optimized the Load() method for faster creation of CreditCard objects
    • Removed redundant string allocation in the CreditCard constructor
• 1.0.0
  • Initial version with card validation functionality