What Is Code Refactoring? Definition, Benefits and Best Practices

Code refactoring in software engineering is the process of restructuring software source code with the purpose to improve its internal structure and non-functional features. At the same time, its external behavior remains unchanged.

The main purpose of code refactoring is pretty clear — to make the code clean, neat, more efficient and maintainable. This process means a kind of software upgrade necessary to improve several non-functional features: maintainability, performance, security, and scalability.

The refactoring process commonly consists of a series of little steps called “micro-refactoring”. At each of these steps, a small alteration to the source code is made. That alteration makes the code simpler and cleaner while system functionality remains the same.

“When you find you have to add a feature to a program, and the program’s code is not structured in a convenient way to add the feature, first refactor the program to make it easy to add the feature, then add the feature.”

Martin Fowler, Refactoring: Improving the Design of Existing Code

What refactoring is not? It does “not” mean:

• software optimization
• rewriting code
• fixing bugs.

What Are the Benefits of Code Refactoring?

As we mentioned above, code refactoring does not change software external behavior. The product functionality remains the same, and users will not see any difference.

Why is it important? There are several reasons why regular code refactoring is important in software development:

1. Simplified support and code updates. Clean code is much easier to update and improve. Developers can quickly make new functionality available for users, as well as save the support budget, as the maintenance will require less working time spent by the programmers involved.
2. Saved time and money in the future. Code refactoring reduces the likelihood of errors in the future and simplifies the implementation of new software functionality. Instead of making sense with tangling code or fixing bugs, developers can start implementing the required functionality at once.
3. Reduced complexity for easier understanding. If the team engages a new employee, or the entire development team changes altogether, it will be easier for new developers to comprehend the code and make the necessary alterations faster.
4. Maintainability and scalability. At times, programmers simply avoid making alterations to some dirty code since they do not clearly understand what consequences these modifications will lead to. The same is true for scalability. Removing this obstacle is another benefit of code refactoring.

Thereby, in a nutshell, both businesses and developers receive two main benefits here: reduce the time and money spent on further use of the software product and can easier understand how everything works.

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When it’s Time to Refactor Your Software’s Code?

It is not difficult to know the right time for refactoring. Here are some common situations when it is worth doing:

• Technical debt gets accumulated. If some similar tasks started to take more time to be completed than they did at the project launch, but the level of their complexity did not change, these are obvious symptoms of accumulated technical debt. It means the project contains more and more complex and confusing pieces of code, architectural failures, and the project scalability itself is difficult.
• It is necessary to scale. Let us presume the product works alright, but it takes too much time to add new functionality, or various issues start appearing as a result of its implementation.
• It is necessary to make the code more understandable. It takes years to develop some software products, and logically, team personnel changes over time. Refactoring makes any code easier to comprehend for new team members.
• It is necessary to reduce upgrade and support costs. Through a business prism, this point is the most important. As we wrote above, clean and well-structured code takes less to update and maintain.

Besides, if you can, you may micro-refactor regularly. For instance, you may spend the last hour of your working day on this activity several times a week.

Code Refactoring in Agile: Best Practices

In the Agile methodology, refactoring is normal practice, as with every new iteration, it will be more difficult to maintain and expand the code if you do not strive to constantly make it cleaner and easier to understand.

Here are some important principles of work to classify as a code refactoring best practices:

1. Move one step at a time. Never try to do everything at once. It is necessary to refactor the code as a series of small micro-modifications not to affect the product’s functionality.
2. Test. The refactoring process should go hand in hand with tests to make sure the alterations made did not result in new bugs.
3. Refactoring should not add new functionality. Never mix this process with modifications to product functionality or adding new features. Code refactoring is a task used to make the code cleaner/more understandable to allow these very functions to be implemented easier and faster.
4. Plan your work and focus on progress. Any code becomes obsolete over time. Consequently, you should accept the fact that such a process will never be 100% completed, and therefore, it is worth seeing it as regular project maintenance.

Code refactoring benefits are not immediately, and its advantages for business are not always obvious. However, in the long run, you will get better code, as well as a calm, more productive work environment, and that makes the investment in such a work reasonable.

If, having read this article, you understand that code refactoring can be useful for your software product, contact us and Lvivity developers will provide you with detailed advice.