feat: add unit testing explanation

Gildaciolopes · Gildaciolopes · commit 713545ff05d9 · 2025-03-16T05:09:34.000-03:00
diff --git a/advanced/API_consumption.js b/advanced/API_consumption.js
@@ -1,6 +1,6 @@
 // &#128204; JavaScript Intermediate - API Consumption (Fetch & Axios)
 
-// Welcome to the eighth section of the JavaScript Intermediate tutorial!
+// Welcome to the eighth section of the JavaScript Advanced tutorial!
 // Here, you'll learn how to fetch data from APIs using Fetch API and Axios.
 
 // Define API URL for maintainability
diff --git a/advanced/modules_webpack.js b/advanced/modules_webpack.js
@@ -1,6 +1,6 @@
 // &#128204; JavaScript Intermediate - Modules and Webpack
 
-// Welcome to the seventh section of the JavaScript Intermediate tutorial!
+// Welcome to the seventh section of the JavaScript Advanced tutorial!
 // Here, you'll learn how to use JavaScript modules and bundle them with Webpack.
 
 // Using ES6 Modules
diff --git a/advanced/object_oriented.js b/advanced/object_oriented.js
@@ -1,6 +1,6 @@
 // &#128204; JavaScript Intermediate - Object-Oriented Programming (OOP)
 
-// Welcome to the sixth section of the JavaScript Intermediate tutorial!
+// Welcome to the sixth section of the JavaScript Advanced tutorial!
 // Here, you'll learn about Object-Oriented Programming (OOP) in JavaScript.
 
 // Constructor Function
diff --git a/advanced/unit_testing.js b/advanced/unit_testing.js
@@ -0,0 +1,52 @@
+// &#128204; JavaScript Intermediate - Unit Testing
+
+// Welcome to the tenth section of the JavaScript Advanced tutorial!
+// Here, you'll learn the basics of Unit Testing in JavaScript using Jest.
+
+// What is Unit Testing?
+// Unit testing is a software testing method where individual components (functions, modules) are tested independently to ensure they work correctly.
+
+// Setting Up Jest (if using Node.js)
+// 1. Install Jest: npm install --save-dev jest
+// 2. Add a test script in package.json: "test": "jest"
+// 3. Create a test file, e.g., math.test.js
+
+// Writing a Simple Unit Test with Jest
+// File: math.js
+function add(a, b) {
+  return a + b;
+}
+module.exports = add;
+
+// File: math.test.js
+const add = require("./math");
+
+test("adds 2 + 3 to equal 5", () => {
+  expect(add(2, 3)).toBe(5);
+});
+
+// Run tests with: npm test
+
+// Testing Asynchronous Code
+async function fetchData() {
+  return "Hello, World!";
+}
+
+// File: async.test.js
+const fetchData = require("./async");
+
+test("fetches correct data", async () => {
+  const data = await fetchData();
+  expect(data).toBe("Hello, World!");
+});
+
+//  Mocking Functions in Jest
+const fetchUser = jest.fn(() => Promise.resolve({ name: "Alice" }));
+
+test("mocks a function call", async () => {
+  const user = await fetchUser();
+  expect(user.name).toBe("Alice");
+  expect(fetchUser).toHaveBeenCalled();
+});
+
+// &#128161; Practice writing unit tests for your functions to ensure your code is reliable and maintainable!
