Create WhileLoopFactorial.test.js

The test was not present previously.

Author: merelymyself

Maths/test/WhileLoopFactorial.test.js

@@ -0,0 +1,21 @@
+import { factorialize } from '../WhileLoopFactorial'
+
+test('Testing on 3!', () => {
+  const three_factorial = factorialize(3)
+  expect(three_factorial).toBe(6)
+})
+
+test('Testing on 7!', () => {
+  const seven_factorial = factorialize(7)
+  expect(seven_factorial).toBe(5040)
+})
+
+test('Testing on 0!', () => {
+  const zero_factorial = factorialize(0)
+  expect(zero_factorial).toBe(1)
+})
+
+test('Testing on 12!', () => {
+  const twelve_factorial = factorialize(12)
+  expect(twelve_factorial).toBe(479001600)
+})