This README.md file provides a comprehensive guide to your `credit-card-digit-mimic` package, including installation instructions, basic usage, detailed examples, and various integration scenarios. It covers usage in different environments such as Node.js, Express.js, AWS Lambda, Next.js, and React.js, making it a valuable resource for developers looking to implement credit card number masking in their projects.

Certainly! I'll compile all the information into a single README.md file for you. Here's the complete README.md content:

# credit-card-digit-mimic

A package to mimic credit card numbers by masking digits.

## Installation

Install the package using npm:

```bash
npm install credit-card-digit-mimic

Usage

Basic Usage

const { cc_mimic_4, ccmimic_12 } = require('credit-card-digit-mimic');

// Masking the last 4 digits
cc_mimic_4("1111223311112233");

// Masking the first 12 digits
ccmimic_12("1111111111223344");

Output

• cc_mimic_4("1111223311112233") will print 11112233111*****.
• ccmimic_12("1111111111223344") will print ************3344.

Detailed Examples

Example 1: Masking a Valid 16-Digit Credit Card Number

cc_mimic_4("1234567812345678"); // Output: 123456781234****
ccmimic_12("1234567812345678"); // Output: ************5678

Example 2: Handling Credit Card Number Shorter than 16 Digits

cc_mimic_4("12345678"); // Output: try Again Length of Credit card is low 8
ccmimic_12("12345678"); // Output: try Again Length of Credit card is low 8

Example 3: Handling Credit Card Number Longer than 16 Digits

cc_mimic_4("123456781234567890"); // Output: try Again Length of Credit card is exceeded 18
ccmimic_12("123456781234567890"); // Output: try Again Length of Credit card is exceeded 18

Example 4: Edge Case with Exactly 16 Digits

cc_mimic_4("0000000000000000"); // Output: 000000000000****
ccmimic_12("0000000000000000"); // Output: ************0000

Example 5: Masking with Different Characters

const customMask = (ccNumber) => {
  const maskedCC = ccNumber.slice(0, 12).padEnd(16, "#");
  console.log(maskedCC);
};

customMask("1111222233334444"); // Output: 111122223333####

Example 6: Integration in an Express.js Application

const express = require('express');
const { cc_mimic_4, ccmimic_12 } = require('credit-card-digit-mimic');

const app = express();

app.get('/mask', (req, res) => {
  const { ccNumber } = req.query;
  res.send({
    maskedCC4: cc_mimic_4(ccNumber),
    maskedCC12: ccmimic_12(ccNumber)
  });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

Example 7: Using in AWS Lambda with Node.js

1. Set Up Your AWS Lambda Function

Create a new AWS Lambda function and configure it with a Node.js runtime.

2. Add Your Code

Upload your code to the Lambda function.

const { cc_mimic_4, ccmimic_12 } = require('credit-card-digit-mimic');

exports.handler = async (event) => {
  const ccNumber = event.queryStringParameters.ccNumber;

  return {
    statusCode: 200,
    body: JSON.stringify({
      maskedCC4: cc_mimic_4(ccNumber),
      maskedCC12: ccmimic_12(ccNumber)
    }),
  };
};

Example 8: Using in a Next.js Application

// pages/api/mask.js
import { cc_mimic_4, ccmimic_12 } from 'credit-card-digit-mimic';

export default function handler(req, res) {
  const { ccNumber } = req.query;

  res.status(200).json({
    maskedCC4: cc_mimic_4(ccNumber),
    maskedCC12: ccmimic_12(ccNumber)
  });
}

Example 9: Using in a React.js Component

import React, { useState } from 'react';
import { cc_mimic_4, ccmimic_12 } from 'credit-card-digit-mimic';

function MaskCreditCard() {
  const [ccNumber, setCcNumber] = useState('');
  const [maskedCC4, setMaskedCC4] = useState('');
  const [maskedCC12, setMaskedCC12] = useState('');

  const handleMask = () => {
    setMaskedCC4(cc_mimic_4(ccNumber));
    setMaskedCC12(ccmimic_12(ccNumber));
  };

  return (
    <div>
      <input
         type="text"
         value={ccNumber}
         onChange={(e) => setCcNumber(e.target.value)}
         placeholder="Enter credit card number"
       />
      <button onClick={handleMask}>Mask</button>
      <div>
        <p>Masked with last 4 digits: {maskedCC4}</p>
        <p>Masked with first 12 digits: {maskedCC12}</p>
      </div>
    </div>
  );
}

export default MaskCreditCard;

Example 10: Masking Credit Card in a CLI Application

const { cc_mimic_4, ccmimic_12 } = require('credit-card-digit-mimic');
const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

rl.question('Enter a credit card number: ', (ccNumber) => {
  console.log('Masked with last 4 digits: ', cc_mimic_4(ccNumber));
  console.log('Masked with first 12 digits: ', ccmimic_12(ccNumber));
  rl.close();
});

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

License

This project is licensed under the ISC License.

Made by

Rupesh Sharma aka "github.com/rupesh9369"