Build Apps With GitHub Copilot Agent Mode: A Hands-On Exercise

Dec 3, 2025 by Alex Johnson 63 views

Build Applications with GitHub Copilot Agent Mode: A Hands-On Exercise

Hey there! Welcome to this exciting Skills exercise where we'll explore building applications with GitHub Copilot Agent Mode!

GitHub Copilot Agent Mode is revolutionizing the way developers code, offering an AI-powered assistant that can significantly accelerate the development process. In this comprehensive guide, we'll dive deep into the capabilities of Copilot Agent Mode, providing you with a hands-on exercise to unlock its full potential. Let's embark on this journey to discover the future of coding and have some fun along the way! 💻✨

This exercise is designed to be interactive and hands-on, ensuring you gain practical experience with GitHub Copilot Agent Mode. As you progress through each step, I’ll provide updates and guidance in the comments, offering:

✅ Checks on your work to ensure you're on the right track.
💡 Helpful tips and resources to enhance your understanding.
🚀 Celebrations of your progress and accomplishments.

So, let's get started! Good luck, and most importantly, have fun exploring this cutting-edge technology!

What is GitHub Copilot Agent Mode?

Before we jump into the exercise, let's understand what GitHub Copilot Agent Mode is and why it's a game-changer for developers. GitHub Copilot is an AI pair programmer that helps you write code faster and with less effort. Agent Mode takes this a step further by allowing Copilot to act more autonomously, understanding your project's context and providing more intelligent suggestions and solutions. It's like having an experienced developer by your side, ready to assist you with any coding challenge.

Key Features of GitHub Copilot Agent Mode

Intelligent Code Completion: Copilot analyzes your code and provides suggestions in real-time, helping you write code faster and more efficiently. It understands the context of your project, suggesting relevant code snippets, functions, and even entire blocks of code.
Automated Code Generation: With Agent Mode, Copilot can generate code based on natural language descriptions. You can simply describe what you want to achieve, and Copilot will write the code for you. This is incredibly useful for quickly prototyping new features or implementing complex algorithms.
Context-Aware Suggestions: Copilot considers your coding style, project structure, and dependencies to offer personalized suggestions. This ensures that the code it suggests is not only correct but also fits seamlessly into your existing codebase.
Debugging Assistance: Copilot can help you identify and fix bugs by suggesting solutions based on the error messages and the surrounding code. It can analyze your code, identify potential issues, and provide recommendations to resolve them, saving you valuable debugging time.
Learning and Adaptation: Copilot learns from your coding patterns and preferences, becoming more effective over time. The more you use it, the better it understands your style and the more accurate its suggestions become.
Integration with VS Code and Other IDEs: GitHub Copilot seamlessly integrates with popular Integrated Development Environments (IDEs) like Visual Studio Code, making it easy to incorporate into your existing workflow. This integration ensures a smooth and efficient coding experience.

Benefits of Using GitHub Copilot Agent Mode

Increased Productivity: By automating many of the repetitive tasks in coding, Copilot helps you write code faster and more efficiently. This allows you to focus on the more creative and strategic aspects of your work.
Reduced Errors: Copilot's intelligent suggestions and debugging assistance help you avoid common coding mistakes, leading to higher quality code.
Improved Code Quality: By suggesting best practices and optimized code snippets, Copilot helps you write cleaner and more maintainable code.
Enhanced Learning: Copilot can help you learn new programming languages and techniques by providing examples and explanations of how code works.
Faster Prototyping: With its ability to generate code from natural language descriptions, Copilot enables you to quickly prototype new ideas and features.

Setting Up for the Exercise

Before we dive into the hands-on exercise, let's make sure you have everything set up correctly. This will ensure a smooth and productive experience.

Prerequisites

GitHub Account: You'll need a GitHub account to participate in this exercise. If you don't have one already, you can sign up for free at GitHub.
GitHub Copilot Subscription: To use GitHub Copilot Agent Mode, you need a Copilot subscription. GitHub offers a free trial for new users, so you can try it out before committing to a subscription.
Visual Studio Code (VS Code): We'll be using VS Code as our IDE for this exercise. If you don't have it installed, you can download it from the official website. VS Code is a powerful and versatile IDE that offers excellent support for a wide range of programming languages and tools.
GitHub Copilot Extension for VS Code: You'll need to install the GitHub Copilot extension for VS Code. This extension integrates Copilot into your IDE, allowing you to access its features directly from your code editor. You can install the extension from the VS Code Marketplace.
Node.js and npm: For this exercise, we'll be building a JavaScript application, so you'll need Node.js and npm (Node Package Manager) installed on your machine. You can download the latest version of Node.js from the official website. npm is included with Node.js, so you don't need to install it separately.

Installing the GitHub Copilot Extension

Open Visual Studio Code.
Click on the Extensions icon in the Activity Bar (or press Ctrl+Shift+X on Windows/Linux or Cmd+Shift+X on macOS).
Search for "GitHub Copilot" in the Extensions Marketplace.
Click the "Install" button next to the GitHub Copilot extension.
Once the extension is installed, you'll be prompted to sign in to your GitHub account. Click the "Sign in" button and follow the instructions to authenticate.

Verifying Your Setup

To ensure that everything is set up correctly, let's create a simple JavaScript file and see if Copilot provides suggestions.

Create a new file named test.js in VS Code.
Type function greet and pause. You should see Copilot suggesting the rest of the function definition.
If you see the suggestions, congratulations! You've successfully set up GitHub Copilot Agent Mode.

Hands-On Exercise: Building a Simple To-Do App

Now that we have everything set up, let's dive into the hands-on exercise. We'll be building a simple to-do application using JavaScript and GitHub Copilot Agent Mode. This exercise will give you a practical understanding of how Copilot can assist you in building real-world applications.

Project Overview

The to-do app will have the following features:

Add new tasks to the list.
Mark tasks as completed.
Delete tasks from the list.
Display the list of tasks.

We'll start by setting up the basic project structure and then use Copilot to help us implement the functionality.

Step 1: Setting Up the Project

Create a new directory for your project. You can do this from your terminal or file explorer.
```
mkdir todo-app
cd todo-app
```
Initialize a new Node.js project using npm.
```
npm init -y
```
This command creates a package.json file in your project directory, which will store information about your project and its dependencies.
Create three files in your project directory:
- index.html: This will be the main HTML file for our application.
- style.css: This will contain the CSS styles for our application.
- script.js: This will contain the JavaScript code for our application.

Step 2: Creating the HTML Structure

Open the index.html file in VS Code and start typing the basic HTML structure. You can use Copilot to speed up this process. For example, start typing <!DOCTYPE html> and Copilot should suggest the rest of the HTML boilerplate.

Here's the basic HTML structure you can use:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>To-Do App</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div class="container">
        <h1>To-Do List</h1>
        <div class="input-group">
            <input type="text" id="taskInput" placeholder="Add a new task...">
            <button id="addTaskButton">Add</button>
        </div>
        <ul id="taskList">
            <!-- Tasks will be added here -->
        </ul>
    </div>
    <script src="script.js"></script>
</body>
</html>

This HTML structure includes:

A container div to hold the content.
A heading for the to-do list.
An input group with a text input and an add button.
An unordered list (ul) to display the tasks.

Step 3: Styling the Application

Open the style.css file and add some basic styles to make the application look presentable. You can use Copilot to help you write the CSS. For example, start typing .container and Copilot should suggest CSS rules for the container.

Here’s a basic CSS stylesheet you can use:

body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 20px;
    width: 400px;
}

h1 {
    text-align: center;
    color: #333;
}

.input-group {
    display: flex;
    margin-bottom: 20px;
}

input[type="text"] {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    margin-right: 10px;
}

button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px 20px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background-color: #3e8e41;
}

#taskList {
    list-style: none;
    padding: 0;
}

#taskList li {
    padding: 10px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

#taskList li:last-child {
    border-bottom: none;
}

#taskList li .completed {
    text-decoration: line-through;
    color: #888;
}

#taskList li .deleteButton {
    background-color: #f44336;
    color: white;
    border: none;
    padding: 5px 10px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 14px;
    border-radius: 4px;
    cursor: pointer;
}

#taskList li .deleteButton:hover {
    background-color: #da190b;
}

These styles provide a clean and simple look for our to-do application.

Step 4: Implementing the JavaScript Functionality

Now, let's add the JavaScript code to make our application interactive. Open the script.js file and start implementing the functionality. This is where GitHub Copilot Agent Mode can be incredibly helpful. You can start by typing comments describing what you want to achieve, and Copilot will suggest the code for you.

Here’s the JavaScript code you can use:

// Get references to the input and button elements
const taskInput = document.getElementById('taskInput');
const addTaskButton = document.getElementById('addTaskButton');
const taskList = document.getElementById('taskList');

// Function to add a new task to the list
function addTask() {
    // Get the task text from the input
    const taskText = taskInput.value.trim();

    // If the task text is not empty
    if (taskText !== '') {
        // Create a new list item
        const listItem = document.createElement('li');

        // Create a span for the task text
        const taskSpan = document.createElement('span');
        taskSpan.innerText = taskText;

        // Create a delete button
        const deleteButton = document.createElement('button');
        deleteButton.innerText = 'Delete';
        deleteButton.className = 'deleteButton';

        // Add a click event listener to the delete button
        deleteButton.addEventListener('click', function() {
            listItem.remove();
        });

        // Add a click event listener to the task span to toggle completed class
        taskSpan.addEventListener('click', function() {
            taskSpan.classList.toggle('completed');
        });

        // Append the task span and delete button to the list item
        listItem.appendChild(taskSpan);
        listItem.appendChild(deleteButton);

        // Append the list item to the task list
        taskList.appendChild(listItem);

        // Clear the input
        taskInput.value = '';
    }
}

// Add an event listener to the add button
addTaskButton.addEventListener('click', addTask);

// Add an event listener to the input for pressing Enter
taskInput.addEventListener('keypress', function(event) {
    if (event.key === 'Enter') {
        addTask();
    }
});

This JavaScript code does the following:

Gets references to the input and button elements.
Defines a function to add a new task to the list.
Creates a new list item with a span for the task text and a delete button.
Adds click event listeners to the delete button and task span.
Appends the list item to the task list.
Adds an event listener to the add button to call the addTask function.
Adds an event listener to the input to add a task when the Enter key is pressed.

Step 5: Testing the Application

Open the index.html file in your browser to test the application. You should be able to add tasks, mark them as completed, and delete them.

Tips for Using GitHub Copilot Agent Mode Effectively

Write Clear Comments: Copilot uses comments to understand your intentions, so writing clear and descriptive comments can help it provide better suggestions.
Break Down Complex Tasks: If you have a complex task, break it down into smaller, more manageable steps. This will make it easier for Copilot to assist you.
Review Copilot's Suggestions: While Copilot is a powerful tool, it's not perfect. Always review its suggestions to ensure they are correct and fit your needs.
Experiment with Different Approaches: Copilot can suggest multiple ways to solve a problem, so experiment with different approaches to find the best solution.
Use Copilot to Learn: Copilot can help you learn new programming languages and techniques by providing examples and explanations of how code works.

Conclusion

Congratulations on completing this hands-on exercise! You've now had a taste of how GitHub Copilot Agent Mode can accelerate your development process and make coding more efficient and enjoyable. By using Copilot effectively, you can focus on the creative aspects of coding and build amazing applications with less effort.

Remember, GitHub Copilot is a powerful tool that is constantly evolving. Keep exploring its features and experimenting with different approaches to get the most out of it. Happy coding!

For more information on GitHub Copilot and its capabilities, visit the official GitHub Copilot documentation.