test: add playground lab to practice

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
   "cSpell.words": [
+    "fabonacci",
     "fastify",
     "todos"
   ]

backend/src/utils/math.ts

@@ -0,0 +1,10 @@
+export function myCustomAdd(a: number, b: number): number {
+  return a + b
+}
+
+export function fabonacci(n: number): number {
+  if (n === 1 || n === 2) {
+    return 1
+  }
+  return fabonacci(n - 1) + fabonacci(n - 2)
+}

backend/test/playground.test.ts

@@ -0,0 +1,35 @@
+import { describe, test, expect, it } from 'vitest'
+import { myCustomAdd, fabonacci } from '../src/utils/math'
+import { fail } from 'assert'
+
+describe('my testing playground', () => {
+  test('it works', () => {
+    const expected = true
+    const actual = false
+    expect(actual).toBe(expected)
+  })
+
+  describe('add function testing', () => {
+    it('should return 3 when add 1 and 2', () => {
+      expect(myCustomAdd(1, 2)).toBe(3)
+    })
+    it('should return 5 when add 2 and 3', () => {
+      // TODO: fix the test
+      fail('not implemented')
+    })
+  })
+
+  describe('fabonacci testing', () => {
+    it('should return 1 when n is 1', () => {
+      expect(fabonacci(1)).toBe(1)
+    })
+    it('should return 1 when n is 2', () => {
+      // TODO: fix the test
+      fail('not implemented')
+    })
+    it('should return 2 when n is 3', () => {
+      // TODO: fix the test
+      fail('not implemented')
+    })
+  })
+})