Add test

calculator.js

+const add = (a, b) => {
+  return a + b;
+}
+
+const minus = (a, b) => {
+  return a - b;
+}
+
+module.exports = {
+  minus,
+  add,
+};
\ No newline at end of file

package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest"
   },
   "author": "",
   "license": "ISC",

tests/calculator.test.js

+const calculator = require('../calculator')
+
+describe('Add function', () => {
+  test('Should return 2 if a = 1 and b = 1', () => {
+    // Arrange
+    const a = 1;
+    const b = 1;
+
+    // Act
+    const result = calculator.add(a, b);
+
+    // Assert
+    expect(result).toEqual(2);
+  });
+});
\ No newline at end of file