fix(isCreditCard): fix Mastercard regex anchoring and digit length check

Author: SarthakDudhe

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}$/;
+  mastercard: /^(?:5[1-5][0-9]{14}|(?:222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12})$/,
   unionpay: /^(6[27][0-9]{14}|^(81[0-9]{14,17}))$/,
   visa: /^(?:4[0-9]{12})(?:[0-9]{3,6})?$/,
 };

test/validators.test.js

@@ -6598,6 +6598,11 @@ describe('Validators', () => {
         '6765780016990268',
         '8171999927660000',
         '8171999900000000021',
+        '5108',
+        'foo2222155765072228',
+        '2222155765072228foo',
+        '51080000000000',
+        '51080000000000000',
       ],
     });
   });