add(math): average functionality (#50)

src/maths/basic.ts

@@ -38,4 +38,12 @@ export const divide = (...args: number[]): number => {
   return rest.reduce((acc, num) => (num !== 0 ? acc / num : acc), first);
 };
 
-// TODO : Add more math operations
+/**
+ * Return the average of numbers
+ */
+
+export const average = (...args: number[]): number => {
+  if (args.length === 0) return 0;
+  const total = args.reduce((acc, num) => acc + num, 0);
+  return total / args.length;
+};

tests/math.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { sum, subtract, multiplication, divide } from '../src/maths/basic.js';
+import { sum, subtract, multiplication, divide, average } from '../src/maths/basic.js';
 
 describe('Math module helper', () => {
   it('should pass sum', () => {
@@ -25,4 +25,10 @@ describe('Math module helper', () => {
     let b = 20;
     expect(divide(a, b));
   });
+  it('should pass average', () => {
+    let a = 10;
+    let b = 20;
+    let c = 30;
+    expect(average(a, b, c)).toBe(20);
+  });
 });