creditCard: function()

in site/semantic/src/definitions/behaviors/form.js [1421:1523]

• 80 lines of code
• 5 McCabe index (conditional complexity)

    creditCard: function(cardNumber, cardTypes) {
      var
        cards = {
          visa: {
            pattern : /^4/,
            length  : [16]
          },
          amex: {
            pattern : /^3[47]/,
            length  : [15]
          },
          mastercard: {
            pattern : /^5[1-5]/,
            length  : [16]
          },
          discover: {
            pattern : /^(6011|622(12[6-9]|1[3-9][0-9]|[2-8][0-9]{2}|9[0-1][0-9]|92[0-5]|64[4-9])|65)/,
            length  : [16]
          },
          unionPay: {
            pattern : /^(62|88)/,
            length  : [16, 17, 18, 19]
          },
          jcb: {
            pattern : /^35(2[89]|[3-8][0-9])/,
            length  : [16]
          },
          maestro: {
            pattern : /^(5018|5020|5038|6304|6759|676[1-3])/,
            length  : [12, 13, 14, 15, 16, 17, 18, 19]
          },
          dinersClub: {
            pattern : /^(30[0-5]|^36)/,
            length  : [14]
          },
          laser: {
            pattern : /^(6304|670[69]|6771)/,
            length  : [16, 17, 18, 19]
          },
          visaElectron: {
            pattern : /^(4026|417500|4508|4844|491(3|7))/,
            length  : [16]
          }
        },
        valid         = {},
        validCard     = false,
        requiredTypes = (typeof cardTypes == 'string')
          ? cardTypes.split(',')
          : false,
        unionPay,
        validation
      ;

      if(typeof cardNumber !== 'string' || cardNumber.length === 0) {
        return;
      }

      // verify card types
      if(requiredTypes) {
        $.each(requiredTypes, function(index, type){
          // verify each card type
          validation = cards[type];
          if(validation) {
            valid = {
              length  : ($.inArray(cardNumber.length, validation.length) !== -1),
              pattern : (cardNumber.search(validation.pattern) !== -1)
            };
            if(valid.length && valid.pattern) {
              validCard = true;
            }
          }
        });

        if(!validCard) {
          return false;
        }
      }

      // skip luhn for UnionPay
      unionPay = {
        number  : ($.inArray(cardNumber.length, cards.unionPay.length) !== -1),
        pattern : (cardNumber.search(cards.unionPay.pattern) !== -1)
      };
      if(unionPay.number && unionPay.pattern) {
        return true;
      }

      // verify luhn, adapted from  <https://gist.github.com/2134376>
      var
        length        = cardNumber.length,
        multiple      = 0,
        producedValue = [
          [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
          [0, 2, 4, 6, 8, 1, 3, 5, 7, 9]
        ],
        sum           = 0
      ;
      while (length--) {
        sum += producedValue[multiple][parseInt(cardNumber.charAt(length), 10)];
        multiple ^= 1;
      }
      return (sum % 10 === 0 && sum > 0);
    },