recreated validateCreditCard.js

Author: Fithi-Teklom

Sprint-3/3-stretch/ validateCreditCard.js

@@ -0,0 +1,25 @@
+function validateCreditCard(number) {
+  const numStr = String(number);
+
+  // Must be exactly 16 digits, only numbers
+  if (!/^\d{16}$/.test(numStr)) return false;
+
+  // Must contain at least two different digits
+  const uniqueDigits = new Set(numStr);
+  if (uniqueDigits.size < 2) return false;
+
+  // Last digit must be even
+  const lastDigit = Number(numStr[numStr.length - 1]);
+  if (lastDigit % 2 !== 0) return false;
+
+  // Sum must be greater than 16
+  const sum = numStr
+    .split("")
+    .map(Number)
+    .reduce((a, b) => a + b, 0);
+  if (sum <= 16) return false;
+
+  return true;
+}
+
+module.exports = validateCreditCard;

Sprint-3/3-stretch/validateCreditCard.test.js

@@ -1,3 +1,5 @@
+const validateCreditCard = require("./validateCreditCard");
+
 test("valid credit card numbers should return true", () => {
   expect(validateCreditCard("9999777788880000")).toBe(true);
   expect(validateCreditCard("6666666666661666")).toBe(true);