Most clients want their application to be developed fast, cost-effectively, and reliably. However, in chase of time and money-saving, quality is often put aside and some quality-improving activities are laid upon a shelf. Refactoring is in a row of such activities and seems to be less tangible as testing for instance. There goes a reasonable question from the client "if it works, why do we need to refactor it?" Still the necessity of code cleaning up may not be always evident.
- What is code refactoring?
- Why your application needs refactoring
- Consequences of Technical Debt
- When refactoring should be considered
- Tips and Tricks
- The bottom line
What is code refactoring?
Code refactoring is a process of application code's editing and cleaning up behind the scenes which optimize its internal structure, but without changing its external behavior and functionalities. Still, this is an inherent part of any project development. However, the necessity of code refactoring may not be really obvious for external observers.
Why your application needs refactoring
Still curious why code refactoring is so important? There are some main reasons to include this activity in your project.
Maintainability and Extensibility
The main goal of code refactoring is to make code more maintainable and extendable. Updates and upgrades added to the application are a continuous and essential process. So the existing code should make this process possible. For instance, integration of some functionalities may not be taken into account when designing initial architecture, so new features may require these changes in overall development approach and code as well.
In general, looking back and organizing the current code before adding new functionalities will not only improve the quality of the application itself, it will make it easier for future developers to build on the source code.
Moreover, when the codebase is unstructured and built inefficiently, developers doubt about making any changes. On the contrary, well-organized and clean code motivates developers to keep order and add improvements.
The metaphor of broken windows suits well to this case. A building with broken windows looks like nobody cares about it. So other people stop caring. They allow more windows to become broken. Eventually, they actively break them. They despoil the facade with graffiti and allow garbage to collect. One broken window starts the process toward decay.
So it is better to prevent any "broken windows" from the very beginning.
This benefit is tightly connected with the previous one. The code that is easy to read reduces developer's efforts for its understanding. Moreover, such code refactoring makes Quality Assurance and bugs identification processes much smoother. It doesn’t remove bugs indeed, but this helps to prevent them in the future.
Another potential purpose of code refactoring is performance improvement. So refactoring may enable an application to perform faster or use fewer server capacities. This is the benefit that might be really tangible for end users right after code refactoring.
In a long perspective refactoring activities should lead to cost reduction according to benefits noticed above. Refactoring contributes to the occurrence of reusable design elements that may be simply used for new features in the future. Well-structured and organized code doesn't require much time for knowledge transfer if proceeding development or support by another developer. Moreover, code refactoring favors bugs' prevention which implies time and costs saving.
Consequences of Technical Debt
Lack of refactoring can result in accumulating technical debt (also known as tech or code dept) - the results when development teams take actions to expedite the delivery of a piece of functionality or a project which later needs to be refactored. In other words, it's the result of prioritizing speedy delivery over perfect code. The longer you don’t care about the minor issues along the way, the more likely they will grow into major complexities.
There are few main high-level consequences caused by accumulated technical debt which keeps building up in the system with time being:
- new features developed and delivered much slower;
- knowledge transfer to new developers joining the project is more inefficient;
- estimates are inaccurate which result in missed deadlines;
- the client is locked with a software development provider which may hardly be changed.
So sooner or later the debt should be paid off, in order an application proceeds working and improving.
When refactoring should be considered
Although the benefits of refactoring may appear only in a long perspective, this should be considered as soon as possible in order not to increase technical debt.
Since application's functionalities do not depend on refactoring and only code changes, a developer himself or a tech lead reviewing the code should define when and what refactoring is necessary. Refactoring is usually irreplaceable if noticing a so-called "code smell" which means disregard of fundamental design principles, weaknesses in code design, duct tape using that all lead to development slowing down and the risk of bugs or failures growth in the future.
The following points may trigger refactoring activities:
- The code is hard to read and too bulky;
- Duplication of code portions is frequently used in an application;
- The opportunities of existing application should be increased;
- Lots of featuring conditional operators used in a code.
In opposition to "smelling code" experts use the definition of "clean code" which is the final goal of any quality improvement including refactoring. Thinking from this perspective, refactoring may be considered if there occur missing features of a "clean code" as the following:
- The logic of code is straightforward which makes it hard for bugs to hide;
- The dependencies are minimal which simplifies maintenance;
- Performance is close to optimal without unnecessary optimizations;
- Clean code contains no duplication and minimizes the number of entities such as classes, methods, functions, and so on.
In general, refactoring may be considered each time adding any improvements or new features to the developed portion of the application.
This may sound weird but another appropriate time to consider refactoring is right after deployment on production and testing an application on real users when it becomes clear, if performance and productivity of the application are sufficient. Moreover after the product delivery to the market, finally there are no strict deadlines, and a development team may take a deep breath and dedicate some time for "housekeeping".
When refactoring is unnecessary
There may occur cases when an application needs to be completely rewritten from the start and it is much more cost- and time-efficient to simply start from scratch so that refactoring is not necessary. This may happen when code is completely unreadable, impossible to maintain, or extend with new features, too outdated. In other words refactoring was not performed on time which caused these crucial issues and now it seems like efforts dedicated to the correction of failures and further refactoring outweighs the effort dedicated to the application’s full redevelopment.
Another case in which it would be wise to postpone refactoring for some time is if development has some strict deadlines and market delivery timeframes. Refactoring can be like going down the proverbial rabbit hole: Once you start, it might demand more time than expected. Still, the possibility of code refactoring should be reconsidered as soon as the deadline passed.
It’s probably not worth refactoring if your application is not going to extend. On the other hand, if the code is for further usage, there will always be functionalities to be added or updated later, so it makes sense to put the investment into refactoring.
Tips and Tricks
There are some best practices that can help to make refactoring reasonable and effective:
1) Refactoring should be considered before adding new features. As soon as there occurs a requirement to add new functionality or update, it is a good idea to refactor existing code. Of course this will extend the project's timeline, but this will also reduce the amount of technical debt that you have to deal with in the future.
2) Refactoring should be planned and estimated carefully. It is important to assess the scope of work needed and to give reasonable estimates of this work in order to stick to the project's deadlines. Code refactoring may still reveal some unpredictable issues which will demand longer time than expected, so it is better to put an extra cushion of time into estimates, so that not to ruin expectations regarding the application delivery plan.
3) Refactoring should be accompanied by unit tests. The purpose of refactoring not only to clean up code but to maintain the system working well. So in order to check up, if nothing is broken, unit tests are imperative. As the writing of unit tests demands time as well, it is better to introduce them from the very beginning of the project.
4) QA team should be involved in the refactoring process. As refactoring shouldn't but still may affect the external behavior of the application, this is relevant to involve the testing team to perform the regression testing of modified application's portion and connected parts.
Both unit testing and regression testing should be performed as a part of refactoring efforts. This will ensure that the functionality of the solution was not affected in any way.
The bottom line
Refactoring is an essential part of each project. In order to understand its necessity easier, one can think of code refactoring as keeping an office desk clean and organized. When you keep order, you’re less stressed because everything is just easier to find and operate. On the other hand, a desk with odd stuff can lead to a chaotic and stressful environment.
The same is true for written code. Keep in mind the necessity of regular cleaning up of your code and you’ll get a higher quality application and a more peaceful and effective work environment.