Any developer shivers a little when they hear the expression “code refactoring”. And reasonably. After all, changing the code structure without changing the behaviour of software is an arduous task.

Code refactoring is like cleaning and organizing a closet when the objects inside fall out as soon as you open the door. When a closet is at this level of disorganization, it is difficult to find what is causing problems in the structure – in addition to being stressful every time someone has to go look for an object.

In software development, a clean code structure is essential for efficient debugging and even code maintenance becomes a herculean task. Code refactoring is, therefore, a strategy used by developers to better work on software.

 

Table of contents

What is code refactoring?

• Legacy code and why to refactor it

 

Code refactoring – The guidelines

• Code refactoring techniques

 

Conclusion

 

What is code refactoring?

When the code structure is obsolete and/or disorganized, it is necessary to clean the code and modify it without changing the behaviour of the software. This technique is called “code refactoring” and prevents software source code from deteriorating.

This source code, which may have been or may become obsolete, is called legacy code and often needs to be cleaned and reorganized.

 

Legacy code and why refactoring it

When source code becomes obsolete it is called legacy code. This means that this code may no longer support hardware, has an antiquated architecture or does not have automated tests. This type of code loses its usefulness and easily becomes an obstacle whenever a developer has to work with it. Furthermore, legacy code is more susceptible to bugs being introduced.

As it is a vulnerable type of source code, many programmers are faced with the arduous task of refactoring it. The code refactoring strategy has many more benefits than just making the source code more current.

Thus, with “code refactoring”, it is possible:

• Give more peace of mind to developers who have to work with this source code;
• Save time spent on debugging;
• Eliminate bugs efficiently;
• Simplify the design, giving it contemporary characteristics;
• Improve code readability;
• Make source code maintenance more convenient;
• Reduce coupling between classes and modules, making the code more flexible.
• Reduce resource consumption;
• Speed ​​up the introduction of new features to the software;
• Drive innovation within the same software.

 

Code refactoring – The guidelines

Starting code refactoring work requires prior planning and organization so that programmers do not get lost in the objective and the steps they need to follow to complete the task.
The first step is to have a clear purpose. For code refactoring, this purpose may be related to reducing the complexity of the source code, improving its readability or even eliminating any existing redundancies.

After defining an objective, you need to create an action plan. This plan must address the various phases of the process and the purpose of each part. This way, the work has a guiding line and progresses more quickly and without errors.

Within the plan, the phases of the project itself may encompass all the small steps of the process. Many developers find it more efficient to refactor code gradually to minimize errors and not make legacy code more vulnerable.

And, for the entire process to progress quickly and efficiently, it is important to collaborate with other developers (in pair programming, for example), testers and other members of the operations team.

This collaboration must be intrinsic especially with testers, since one of the problems with legacy code that leads to code refactoring is the lack of efficient automated tests. Furthermore, it is the testers who ensure that the code continues to work as expected and that no software function is affected by the simplification of the legacy code.

Just as tests will need to be automated, other phases of code refactoring can be optimized through automation, such as analysis and workflow tools.

 

Code refactoring techniques

To improve and simplify source code that is already obsolete and causing problems for the software, developers have around five different techniques to carry out these code refactoring techniques:

• Extraction – This involves dividing a block of code into several parts so that it is easier to read, manage refactoring and apply other techniques.
• Renaming variables and code blocks – To make it easier to locate a piece of code, it is customary to add a name and description to the small parts that were extracted from a larger block. This way, errors caused by ambiguity are minimized.
• Simplify conditional expressions – More complex conditional expressions can be difficult to read and understand. Therefore, developers responsible for code refactoring simplify them and thus reduce errors caused by misunderstandings.
• Eliminate duplicate code – Repeated code snippets take up space, weigh down the software and perform no function. Removing these lines of code is essential to reduce the code base and reduce errors caused by redundancy or even inconsistency.
• Restructuring code – Perhaps the most important of the code refactoring techniques and serves to improve the way the base code is organized and will be read. Code restructuring can involve creating new classes and moving code between them, but also disallowing public access to implementation details.

 

Conclusion

Between testers, developers and other members of the operations team, carrying out code refactoring is a challenging strategy. However, this is also essential for cleaning up the source code and improving its language.

Among the reasons that lead a team to start working on code refactoring is the fact that the base code may be obsolete, confusing and/or have vulnerabilities. In any case, it needs to become more readable and stop having ambiguous or duplicated expressions so that the software or hardware it supports does not lose its functions.