WhileLoopFactorial: Optimize and add tests

Maths/WhileLoopFactorial.js

@@ -1,15 +1,13 @@
 /*
-    author: Theepag
+    author: Theepag, optimised by merelymyself
  */
 export const factorialize = (num) => {
-  // Step 1. variable result to store num
-  let result = num
-  // If num = 0 OR 1, the factorial will return 1
-  if (num === 0 || num === 1) { return 1 }
+  // Step 1. Handles cases where num is 0 or 1, by returning 1.
+  let result = 1
   // Step 2. WHILE loop
   while (num > 1) {
+    result *= num // or result = result * num;
     num-- // decrement 1 at each iteration
-    result = result * num // or result = result * num;
   }
   // Step 3. Return the factorial
   return result

Maths/test/WhileLoopFactorial.test.js

@@ -0,0 +1,17 @@
+import { factorialize } from '../WhileLoopFactorial'
+
+test('Testing on 3!', () => {
+  expect(factorialize(3)).toBe(6)
+})
+
+test('Testing on 7!', () => {
+  expect(factorialize(7)).toBe(5040)
+})
+
+test('Testing on 0!', () => {
+  expect(factorialize(0)).toBe(1)
+})
+
+test('Testing on 12!', () => {
+  expect(factorialize(12)).toBe(479001600)
+})