Credit Card Validation for VueJS

validators.ts

const mustBeValidDateFormat = (value: string): boolean => /^[0-9.\/]+$/i.test(value);

const mustBeValidMonth = (value: string): boolean => {
  const [month] = value.split('/');
  if (!/^\d*$/.test(month)) { return false; }
  const inputMonth = parseInt(month, 10);

  return inputMonth > 0 && inputMonth < 13;
};

const mustBeValidYear = (value: string): boolean => {
  const [_, year] = value.split('/');
  const currentYear = new Date().getFullYear();
  if (typeof year === 'undefined') { return false; }
  if (year.length !== 4) { return false; }
  if (!/^\d*$/.test(year)) { return false; }

  const y = parseInt(year, 10);
  // Amazon goes 20 years into the future
  const MAX_YEARS_IN_THE_FUTURE = 20;
  return y >= currentYear && y <= currentYear + MAX_YEARS_IN_THE_FUTURE;
};

const mustNotBeExpired = (value: string): boolean => {
  const [month, year] = value.split('/');
  if (typeof year === 'undefined' || typeof month === 'undefined') { return false; }

  const currentYear = new Date().getFullYear();
  const currentMonth = new Date().getMonth() + 1;

  const parsedYear = parseInt(year, 10);
  const parsedMonth = parseInt(month, 10);

  if (parsedYear === currentYear) {
    return parsedMonth >= currentMonth;
  } else {
    return parsedYear >= currentYear;
  }
};

const mustBeValidName = (value: string): boolean => /^[^\d]+$/i.test(value);

const mustBeValidCardNumber = (value: string): boolean => {
  if (!value) { return false; }
  if (!/^[\d\s\-]+$/.test(value)) { return false; }
  const cc = value.replace(/\-|\s/g, '');

  // The Luhn Algorithm
  // https://medium.com/@ma.juber/mathematics-behind-credit-debit-card-numbering-340bf68d27d2
  let i = cc.length - 1;
  let bit = false;
  let sum = 0;
  let val: number;

  while (i >= 0) {
    val = parseInt(cc.charAt(i), 10);

    if (bit) {
      val *= 2;
      if (val > 9) {
        val = (val % 10) + 1; // eslint-disable-line no-extra-parens
      }
    }
    bit = !bit;
    sum += val;
    i--;
  }
  return sum % 10 === 0;
};

// Shamelessly stolen from: https://gist.github.com/maximkott/31dfdd37d4c0fee499de453faca17c83
const applyDateMask = (value: string, mask: string, maskPatterns: { [key: string]: RegExp }): string => {
  value = value || '';
  mask = mask || '';
  maskPatterns = maskPatterns || {};

  let maskedValue = '';
  const valueParts = value.split('');
  const maskParts = mask.split('');

  while (valueParts.length > 0) {
    let unmaskedChar = valueParts.shift();
    while (unmaskedChar !== null) {
      const maskChar = maskParts.shift();
      if (maskChar !== undefined) {
        const maskPattern = maskPatterns[maskChar.toUpperCase()];
        if (maskPattern !== undefined) {
          let check = false;
          if (maskPattern instanceof RegExp) {
            check = maskPattern.test(unmaskedChar);
          }
          if (check) {
            maskedValue += unmaskedChar;
          } else {
            maskParts.unshift(maskChar);
          }

          unmaskedChar = null;
        } else {
          maskedValue += maskChar;
        }
      } else {
        unmaskedChar = null;
      }
    }
  }
  return maskedValue;
};

const removeDateMask = (cardDate: string): string => {
  return cardDate.replace('/', '');
};

export {
  mustBeValidDateFormat,
  mustBeValidName,
  mustBeValidCardNumber,
  mustNotBeExpired,
  applyDateMask,
  removeDateMask,
  mustBeValidMonth,
  mustBeValidYear
};