Code Refactoring Best Practises: When & Why to Modernize Software
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Why is refactoring your code important?
Let’s imagine you are going to release your product and you are almost there: just adding one more function before delivering the ultimate product. Naturally, sometimes developers don’t have time to create well-designed and clean code trying to meet business deadlines and goals. As a result, certain functionalities are added in a haphazard way in order to hit a deliverable or a deadline.
The scenario unfolds as follows: product launch is successful, everything works smoothly, however, an extra development work looms in the near future. Why is that, you will ask? Because a solution released under tight deadlines when code is implemented in a fast fashion contains code that is redundant and poorly designed.
Note: With clean code, it is much easier to implement future iterations and innovations and scale the software product.
Here we talk about technical debt which means a middle ground/ balance between a perfectly developed product and tight deadlines required for the product launch. This tradeoff prevents developers from creating clean and organized codes which leads to temporarily speeding up without writing necessary tests for new features or functionality. Eventually, delayed refactoring is one of the reasons for technical debt. In our article, we are going to take a deep dive into code refactoring as a way to reduce technical debt.
So what is code refactoring?
Code refactoring is defined as a technique to restructure and clean up an existing body of code without altering the function of the code (or external behavior) at all. It is also one of the common legacy software modernization approaches. The main goal of code refactoring lies in reducing technical costs by timely cleaning up the code while preserving its functionality. Among the basic purposes are: enhance code readability; reduce complexity; improve source code’s maintainability; improve extensibility; enhance performance; facilitate fast program execution.
With the refactoring approach, developers apply a standardized basic of micro-refactoring allowing a source code to preserve the external behavior of the software. Since each code transformation is a tiny change, it’s less likely to go wrong and break the code.
We also want to emphasize the difference between code refactoring and code rewriting since these two notions are usually confused. In contrast to code rewriting, code refactoring doesn’t change the software functionality: it only cleans up the code making it simpler and optimized.
Benefits of code refactoring in software engineering
Above we have pointed out the main purposes of code refactoring and why it is important for software product development. Let’s delve into the issues and reasons why and when code refactoring is a must-do technique for your product enhancement.
1. Maintainable and scalable code.
The applications or software always need upgrades and updates to be fully functional and meet customers’ requirements. In order to scale and be on top of the competition, a product has to constantly introduce new features, but if a code is messy and unclean it is impossible to achieve this goal. Therefore, code refactoring facilitates high-quality updates that can significantly help boost sales.
2. Cost efficiency.
Since code refactoring is executed by small changes called micro-refactorings, the likelihood of errors and bugs in the future is reduced. Moreover, developers can easily implement new functionality to software because there is no need to spend extra time and effort resolving issues and bugs.
3. Improved system performance.
After refactoring, code becomes simple which means fewer server capacities and faster system responses when users interact with it. Benefits are obvious for both developers who add new features to the product and end-users whose customer experiences will become better.
4. Reduced technical debt.
Bad code results in a bad user experience, poor architecture, and much more complicated issues as well. Once you launch your product it doesn’t mean that your software is finalized. If the code is left as it is after the product launch, not well-structured and polished, it can take developers some extra time to understand and track it. Here’s when refactoring comes into play. It helps clean up the shortcuts you took in your code to meet the deadlines. So instead of constantly fixing bugs, it is reasonable to refactor the code before it will gradually decelerate your progress every day until you eventually have to pay off the debt by writing tests or rewriting the code altogether.
When do you need refactoring?
Before identifying the project stages when refactoring is required, let’s take a look at the common situations when it is worth doing:
1. The code is hard to read and understand.
For example, if the software product has been developed for years, it is likely that the development team changed, that’s why refactoring will be a good idea to help new team members comprehend the code and help the development process go smoothly.
2. It is necessary to scale.
In order to reduce time when adding new functionality and fix issues that can occur on the way (due to dirty codes), refactor your code. Refactoring can mitigate minor bugs before they become serious problems.
3. If there are duplications of code portions.
If there are duplications of code portions that are frequently used in the software. Refactoring makes future shifts in the code much easier.
So if you are planning to refactor your code, here are the software development stages when conducting code refactoring is most suitable:
- Development stage. Considering the tendency that due to business requirements, developers mostly have to expedite the delivery of the project that later needs to be refactored, it is always a good idea to clean up a code before the product rolls out. Yes, you can do this after the product launch; however, with bugs and code smell, causing performance decrease, the first impression of your users is likely to be spoiled. Therefore, do not neglect the importance of refactoring.
- Applying new features. If you want to upgrade the product, refactoring is a must-do in order to clean up the code from issues before they start to disseminate. Consequently, you save time and money for yourself or for other development teams in the long run.
- When bugs emerge. Messy code affects customer experience and instead of splurging on marketing, pay attention to code refactoring since whatever marketing techniques you apply, no one will turn their back on the product if it malfunctions. Moreover, business processes can be at risk due to security breaches that may occur when bugs show up in internal systems.
So now it is understandable when and at what stages you need to apply code refactoring, but there are still some situations when you DO NOT need to refactor your code. You might be wondering how it is possible if the significance of refactoring is obvious. Let us shed some light on it to get a holistic view:
- It may be more costly to refactor the code rather than rewrite the code from scratch. Such cases happen when the code is completely unreadable and outdated that is impossible to maintain and extend.
- If the product has strict market delivery timeframes. Maybe, it seems to be paradoxical (considering the above-mentioned tip to refactor a code at the development stage), but sometimes the refactoring process can take much more time than planned. Thus, it will be wise to postpone refactoring and do it once the deadline is passed.
There are plenty of refactoring techniques available. In this section, we are going to cover the most common ones.
Being one of the most popular methods used for code refactoring, the red-green-refactor process is applied in Agile test-driven development. With this method, refactoring is conducted in the following test-driven cycle:
- Red. Considering what first needs to be developed, developers start with writing a failing test.
- Green. The second stage covers writing the simplest code to pass the basic testing.
- Refactor. In the final stage, developers implement improvements.
Abstraction refactoring (dealing with generalization)
Our developers use this technique primarily to reduce unnecessary duplicates and to cope with a large amount of refactoring by applying class inheritances, hierarchy, extractions.
For instance, one of the methods is the Pull-up field, when code parts are moved into the superclass to eliminate the code duplication. In the Pull-down method, the code is moved down into the subclass.
Moving features between objects
With these techniques, new classes can be created and functionality can be safely moved between classes. For example, if there are no additional responsibilities planned in a class, then you might want to move all features from the class to another one and delete it all together; or when a class is responsible for the work of two, you can create a new class and place the fields responsible for the relevant functionality in it.
It is a common practice when during the development phases developers use excessively long methods which affect the execution logic and consequently make the code hard to comprehend and shift. Therefore, composing method helps streamline methods and eliminate code duplications. Let’s take a look at the two popular composing methods:
Extract method – allows breaking down the code into fragments that can be grouped together. These code fragments are moved to separate methods and are replaced with a call to this method.
Inline method – is used to simplify the code and reduce the number of methods by replacing the call to the methods with the content of the method.
Simplifying Conditional Expressions refactoring handles complex logic in the code which over time becomes complicated and hard to understand. The simplifying method calls make the interaction between classes simpler by improving the interfaces.
Code refactoring in Agile methodology: tips and best practices
In Agile software development, well-factored and clean code is the key to project success. Since maintaining and extending the code from iteration to iteration significantly depends on refactoring, devs need to utilize a step-by-step approach breaking down the refactoring process into smaller chunks along with continuous testing. Let’s take a look at core principles of code refactoring to improve source-code maintainability, reduce complexity, and create a more solid internal architecture.
- Estimate and plan refactoring carefully. In order to stick to the project’s deadlines and optimize the code and rich significant software performance improvements within a reasonable timeframe, it is important to assess the scope of work. It may take more time than expected, nevertheless, it is recommended to put extra time into your estimates to accomplish the delivery plan.
- Refactor before adding new features. As soon as you need to add new functionality first perform refactoring to the existing code, even if it will prolong the duration of your project. Otherwise, your technical debt will be increasing which can result in an enormous amount of extra efforts and technical costs for business owners.
- Test, test, test. Throughout the refactoring process, testing is a must-do so that new alterations will not result in bugs affecting the functionality of the project. Moreover, the QA team has to be involved in the refactoring process to test the code, as sometimes it can affect the external behavior of the code.
- Use refactoring automation tools. Refactoring has to be an ongoing practice; and considering the fact that codes tend to become outdated, you can optimize the process of refactoring by applying automation tools. For example, there are IDEs that have built-in refactoring support (Eclipse, VSCode, IntelliJ IDEA).
So do you need your code to be refactored?
Unnecessary clutter in your codebase can be stressful and affect the ultimate project budget. At first glance, it may seem that you can skip refactoring and move further by adding new functionalities to the software product. However, the truth is that with refactoring, the work environment is more productive, and in the long run developers’ efforts and business owners’ investments will be rewarded with an enhanced product and proven customer experience.
Do you still have any questions? Contact our software experts to help you clean up the code or modernize your mission-critical applications to enhance your overall return on investment.