adding basic jest tests

step2-04/index.spec.ts

@@ -0,0 +1,16 @@
+import { square } from '.';
+
+describe('square', () => {
+  beforeEach(() => {
+    console.log('this happens before each test');
+  });
+
+  afterEach(() => {
+    console.log('this happens after each test');
+  });
+
+  it('should be able to give the square of two numbers', () => {
+    console.log('test');
+    expect(square(5)).toBe(25);
+  });
+});