feat: add test for sum function [issue fork-commit-merge#652]

tasks/vitest/easy/src/sum.test.ts

@@ -4,3 +4,8 @@ import sum from "./sum";
 import { describe, expect, it } from "vitest";
 
 // TODO: Create the test required in the task
+describe('sum function test', () => {
+    it('should return 0 when no numbers are provided', () => {
+      expect(sum()).toBe(0);
+    });
+  });