fix(isCreditCard): anchor Mastercard pattern to 16 digits

Author: hong4rc

src/lib/isCreditCard.js

@@ -6,7 +6,7 @@ const cards = {
   dinersclub: /^3(?:0[0-5]|[68][0-9])[0-9]{11}$/,
   discover: /^6(?:011|5[0-9][0-9])[0-9]{12,15}$/,
   jcb: /^(?:2131|1800|35\d{3})\d{11}$/,
-  mastercard: /^5[1-5][0-9]{2}|(222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}$/, // /^[25][1-7][0-9]{14}$/;
+  mastercard: /^(5[1-5][0-9]{2}|(222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720))[0-9]{12}$/,
   unionpay: /^(6[27][0-9]{14}|^(81[0-9]{14,17}))$/,
   visa: /^(?:4[0-9]{12})(?:[0-9]{3,6})?$/,
 };

test/validators.test.js

@@ -6574,10 +6574,13 @@ describe('Validators', () => {
         '2225855203075256',
         '2718760626256570',
         '2720428011723762',
+        '5105105105105100',
         '5398228707871527',
       ],
       invalid: [
         'foo',
+        '5108',
+        '5100000000000000000000003',
         '36050234196908',
         '375556917985515',
         '375556917985515999999993',