Codecademy export

main.js

// All valid credit card numbers
const valid1 = [4, 5, 3, 9, 6, 7, 7, 9, 0, 8, 0, 1, 6, 8, 0, 8];
const valid2 = [5, 5, 3, 5, 7, 6, 6, 7, 6, 8, 7, 5, 1, 4, 3, 9];
const valid3 = [3, 7, 1, 6, 1, 2, 0, 1, 9, 9, 8, 5, 2, 3, 6];
const valid4 = [6, 0, 1, 1, 1, 4, 4, 3, 4, 0, 6, 8, 2, 9, 0, 5];
const valid5 = [4, 5, 3, 9, 4, 0, 4, 9, 6, 7, 8, 6, 9, 6, 6, 6];

// All invalid credit card numbers
const invalid1 = [1, 5, 3, 2, 7, 7, 8, 7, 7, 1, 0, 9, 1, 7, 9, 5];
const invalid2 = [5, 7, 9, 5, 5, 9, 3, 3, 9, 2, 1, 3, 4, 6, 4, 3];
const invalid3 = [3, 7, 5, 7, 9, 6, 0, 8, 4, 4, 5, 9, 9, 1, 4];
const invalid4 = [6, 0, 1, 1, 1, 2, 7, 9, 6, 1, 7, 7, 7, 9, 3, 5];
const invalid5 = [5, 3, 8, 2, 0, 1, 9, 7, 7, 2, 8, 8, 3, 8, 5, 4];

// Can be either valid or invalid
const mystery1 = [3, 4, 4, 8, 0, 1, 9, 6, 8, 3, 0, 5, 4, 1, 4];
const mystery2 = [5, 4, 6, 6, 1, 0, 0, 8, 6, 1, 6, 2, 0, 2, 3, 9];
const mystery3 = [6, 0, 1, 1, 3, 7, 7, 0, 2, 0, 9, 6, 2, 6, 5, 6, 2, 0, 3];
const mystery4 = [4, 9, 2, 9, 8, 7, 7, 1, 6, 9, 2, 1, 7, 0, 9, 3];
const mystery5 = [4, 9, 1, 3, 5, 4, 0, 4, 6, 3, 0, 7, 2, 5, 2, 3];

// An array of all the arrays above
const batch = [
  valid1,
  valid2,
  valid3,
  valid4,
  valid5,
  invalid1,
  invalid2,
  invalid3,
  invalid4,
  invalid5,
  mystery1,
  mystery2,
  mystery3,
  mystery4,
  mystery5,
];

// Add your functions below:
function calculateSum(arr) {
  let sum = 0;

  for (let i = 0; i < arr.length; i++) {
    let currVal = arr[arr.length - 1 - i];

    if (i % 2 !== 0) {
      // doubleValue
      currVal *= 2;
      if (currVal > 9) {
        currVal = currVal - 9;
      }
    }
    sum += currVal;
  }
  return sum;
}

function validateCred(arr) {
  const sum = calculateSum(arr);
  return sum % 10 === 0 ? true : false;
}

function findInvalidCards(creditCards) {
  return creditCards.filter((card) => !validateCred(card));
}

function idInvalidCardCompanies(invalidCreds) {
  let companies = [];
  const accCompanies = [
    "unknown",
    "unknown",
    "unknown",
    "Amex (American Express)",
    "Visa",
    "Mastercard",
    "Discover",
  ];

  return accCompanies.filter((accComp, aIdx) => {
    if (accComp === "unknown") return false;
    return invalidCreds.some((invalidCred, cIdx) => {
      if (aIdx === invalidCred[0]) {
        return true;
      }
      return false;
    });
  });
}

function numberStringToArray(str) {
  return str.replace(" ", "").split("");
}

function isValidCardDigit(num) {
  return typeof currDigit === 'number' && currDigit > 0 && Number.isInteger(currDigit) 
}

function convertInvalidToValid(invalidCreditCard) {
  const sum = calculateSum(invalidCreditCard);
  const modulo = sum % 10;
  if (modulo === 0) {
    console.log("Credit Card is valid!");
  }

  // reverseOrder
  invalidCreditCard.reverse();

  let isNowValid = false;
  invalidCreditCard.some((digit, idx) => {
    //leave company code
    if (idx === 0) {
      return false;
    }

    let currDigit = null

    if (idx % 2 !== 0) {      
      currDigit = ((digit * 2) - modulo) < 10 ? ((digit * 2) - modulo) / 2 : - 1;
      
      if (!isValidCardDigit(currDigit)) {
        currDigit = ((digit * 2) - modulo) > 9 ? (((digit * 2) - modulo) - 9) / 2 : - 1;;
      }

      if (!isValidCardDigit(currDigit)) {
        currDigit = ((digit * 2) + modulo) > 9 ? (((digit * 2) + modulo) - 9) / 2 : - 1;;
      }

      if (!isValidCardDigit(currDigit)) {
        currDigit = ((digit * 2) + modulo) < 10 ? (((digit * 2) + modulo)) / 2 : - 1;;
      }
      if (!isValidCardDigit(currDigit)) {
        return false
      }

    } else {
      if (digit - modulo >= 0) {
        currDigit = digit - modulo;

      } else if (digit + modulo < 10) {
        currDigit = digit + modulo;
      }
    }

    if (!Number.isInteger(currDigit)) {
      return false;
    }
    
    invalidCreditCard[idx] = currDigit;
    isNowValid = true;
    return true;
    
  });

  // reverse to the original order
  invalidCreditCard.reverse();

  if (!isNowValid || !validateCred(invalidCreditCard)) {
    console.error("something went wrong, could not generate a valid card number");
  }

  return invalidCreditCard;
}

console.log("Following should be valid:");
console.log(validateCred(valid1));
console.log(validateCred(valid2));
console.log(validateCred(valid3));
console.log(validateCred(valid4));

console.log('\nFollowing should be invalid:');
console.log(validateCred(invalid1));
console.log(validateCred(invalid2));
console.log(validateCred(invalid3));
console.log(validateCred(invalid4));

console.log('\nInvalid card companies: ');
console.log(idInvalidCardCompanies(findInvalidCards(batch)));

console.log('\nGenerate valid credit card numbers: ');
invalidToValidCardNumber = convertInvalidToValid(invalid1);
console.log('Valid card number (invalid1): ', invalidToValidCardNumber, 'sum: ', calculateSum(invalidToValidCardNumber), ', valid: ', validateCred(invalidToValidCardNumber) ? 'true' : 'false' );
invalidToValidCardNumber = convertInvalidToValid(invalid2);
console.log('Valid card number (invalid2): ', invalidToValidCardNumber, 'sum: ', calculateSum(invalidToValidCardNumber), ', valid: ', validateCred(invalidToValidCardNumber) ? 'true' : 'false' );
invalidToValidCardNumber = convertInvalidToValid(invalid3);
console.log('Valid card number (invalid3): ', invalidToValidCardNumber, 'sum: ', calculateSum(invalidToValidCardNumber), ', valid: ', validateCred(invalidToValidCardNumber) ? 'true' : 'false' );
invalidToValidCardNumber = convertInvalidToValid(invalid4);
console.log('Valid card number (invalid4): ', invalidToValidCardNumber, 'sum: ', calculateSum(invalidToValidCardNumber), ', valid: ', validateCred(invalidToValidCardNumber) ? 'true' : 'false' );