Updated the test system

test/luhnCheck.test.js

@@ -0,0 +1,15 @@
+const expect = require('expect');
+const {luhnCheck} = require('./_30s.js');
+
+test('luhnCheck is a Function', () => {
+  expect(luhnCheck).toBeInstanceOf(Function);
+});
+test('validates identification number', () => {
+  expect(luhnCheck(6011329933655299)).toBeFalsy();
+});
+test('validates identification number', () => {
+  expect(luhnCheck('4485275742308327')).toBeTruthy();
+});
+test('validates identification number', () => {
+  expect(luhnCheck(123456789)).toBeFalsy();
+});