merge: Add test case (#851)

* Add test case

* minor fix

* delete files

* rename file

Recursive/test/Factorial.test.js

@@ -0,0 +1,11 @@
+import { factorial } from '../Factorial'
+
+describe('Factorial', () => {
+  it('should return factorial 1 for value "0"', () => {
+    expect(factorial(0)).toBe(1)
+  })
+
+  it('should return factorial 120 for value "5"', () => {
+    expect(factorial(5)).toBe(120)
+  })
+})