How to Use GitHub Copilot to Refactor Code: A Step-by-Step Guide

In software development, refactoring code is a routine task. It involves changing the structure of the code without altering its functionality. The goal is to improve the code’s readability, reduce complexity, and maintainability. Here’s how you can use GitHub Copilot, an AI-powered tool, to help you with this task.

Understanding Code Refactoring

Code Refactoring refers to the process of restructuring or rearranging the program source code without altering its original functionality. The goal is to improve the software’s structure and design, reduce complexity, and enhance overall efficiency. The integration of AI into code refactoring has expedited the identification of software performance issues and simplified complex algorithms.

How to Use GitHub Copilot for Refactoring

To use Copilot for refactoring, start by installing the GitHub Copilot extension for your language of choice (VS Code, Python, etc.). For example, if you want to refactor a source code written in Python, you can install the Copilot plugin by following these steps:

Step 1: Install the Copilot Extension

To use Copilot for refactoring, start by installing the GitHub Copilot extension for your language of choice (VS Code, Python, etc.). For example, if you want to refactor a source code written in Python, you can install the Copilot plugin by:

• Open the Settings option in the Integrated Development Environment or IDE (JavaScript or Python).
• Click on the plugin option on the left.
• Click on the Marketplace option and search for the GitHub Copilot plugin.
• Once located, click on Install to install the plugin.

The IDE will prompt for a restart once the installation is completed. After restarting, open the IDE and click on Tools -> GitHub Copilot -> Login to GitHub. After successful login, Copilot will be ready for use.

Step 2: Provide the Code

The first step in using Copilot to refactor code is to provide the code that you want to refactor. You can do this by typing or pasting the code into the chat interface. Make sure the code is complete and functional. Copilot works best when it has the full context of the code.

def example_code():
    # This is the code you want to refactor
    pass

Step 3: Specify Your Needs

Next, you need to tell Copilot what you want to achieve with the refactoring. Are you trying to improve readability? Or perhaps you want to optimize the code for performance? Maybe you need to modify the code to follow a certain coding standard? Be as specific as possible about your needs.

# I want to refactor the above code to improve its readability and performance.

Step 4: Use Copilot Shortcuts

To use Copilot, the below shortcuts can be used while writing the code:

Step 5: Wait for Copilot’s Response

Once you’ve provided the code and specified your needs, Copilot will analyze the information and provide a refactored version of your code. This process may take a few seconds.

def refactored_code():
    # This is the refactored code provided by Copilot
    pass

Step 6: Review and Iterate

After receiving the refactored code, review it to see if it meets your requirements. If it does, great! If not, you can provide feedback to Copilot and iterate on the refactoring process. Remember, refactoring is an iterative process, and it may take several attempts to get the code just right.

# The refactored code is good, but I think it could be more concise.

Practical Examples of Code Refactoring with Copilot

Let’s consider a few examples to demonstrate how a complex code can be simplified using the Refactoring feature of Copilot.

Example 1: Simplifying Complex Code

Before Refactoring:

def process_data(data):
# ...lots of code... if data_is_valid(data):
# process the data
# ...lots of code... def data_is_valid(data):
# check if data is valid pass

After Refactoring with Copilot:

def process_data(data):
# ...lots of code... process_valid_data(data)
# ...lots of code... def process_valid_data(data): if data_is_valid(data):
# process the data def data_is_valid(data):
# check if data is valid pass

Explanation:

• Initially, the process_data function handled both processing and validation logic, making it less modular and harder to maintain.
• After refactoring, the code is divided into three functions: process_data, process_valid_data, and data_is_valid, each responsible for a specific task.
• process_valid_data now solely handles processing data if it’s valid, while data_is_valid is responsible for validating the data.
• This separation of concerns improves code readability, maintainability, and modularity.

Example 2: Variable Renaming

Before Refactoring:

def calculate_volume(h, r):
return 3.14 * r * r * h

After Refactoring with Copilot:

def calculate_volume(height, radius):
return 3.14 * radius * radius * height

Explanation:

• Initially, the function calculate_volume accepted parameters named h for height and r for radius.
• After applying refactoring, the parameters were renamed to height and radius, making the code more descriptive and understandable.
• This renaming improves code readability and makes the purpose of each parameter clearer.

In these examples, Copilot’s refactoring suggestions have improved the code by enhancing modularity, readability, and self-explanatory nature, similar to the previous examples.

Conclusion

Refactoring code is an essential part of software development. It helps keep your codebase clean, understandable, and easy to maintain. With Copilot, you have a powerful tool that can assist you in this process. Remember to provide clear instructions and review the refactored code carefully. Always test the refactored code to ensure it still works as expected. Happy coding!

GitHub Copilot has been trained on natural language text and source code from publicly available sources, including code in public repositories on GitHub. It supports various languages but works particularly well with JavaScript, TypeScript, Ruby, Python, Go, C++, and C#.

While Copilot can help us reconstruct the code, it has several limitations, such as incorrect suggestions, overreliance, and refracting outdated codes. Once you have its suggestions, ensure you go through all manual checks and use the right prompts. This is a general guide. The actual process may vary depending on the complexity of your code and your specific needs.