Software is complex and an ever-evolving process of creativity and discovery. Good decisions at the start of a project might unexpectedly lead to unfavorable outcomes or quickly become obsolete. This is often not a failure in decision-making but a result of limited information at the start of the project.
Many see refactoring as simply fixing mistakes, but this is generally not true. Teams are making good, informed decisions based on the level of information they have. As they gather more knowledge, through implementation and practice, those decisions and their implementations will change.
As this knowledge and requirements evolve, code must also adapt. This constant evolution demands a process that manages change without creating barriers that impede progress.
So how do you manage the process?
Refactoring has to become a natural part of software development. However, there’s often resistance to refactoring both from the business end due to misunderstandings about its cost or from other engineers who don’t think it’s necessary.
But the truth is that refactoring is a necessary part of software development.
This guide will explore why regular refactoring is essential and help you understand how to advocate its importance to business teams. It will also give you some tools and tactics that can help you manage the refactoring process.
The Case for Refactoring
Code refactoring must be prioritized because it’s central to the ongoing health and evolution of a software project. In Martin Fowler’s famous book Refactoring, he defines refactoring as “A change made to the internal structure of software to make it easier to understand and cheaper to modify without changing its observable behavior.”
Take a look at a few of the main reasons you should prioritize refactoring:
Boost Software Quality and Reliability
If you’re writing the same code multiple times, it’s a good time to refactor. A codebase with multiple methods copy-pasted in various places creates a level of code duplication that’s difficult to maintain and update. Developers have to change code in multiple places, increasing the risk of introducing bugs and errors.
By refactoring, developers can identify the common logic in these duplicated methods and extract it into a single, reusable method or class. This falls in line with the don’t repeat yourself (DRY) concept that suggests reusing code, configurations, and documentation across a system instead of duplicating them in multiple places.
Additionally, refactoring makes complex codebases simpler with code that’s easier to read and understand, and less prone to errors. As a result, developers spend less time trying to figure out what the code does and are less likely to introduce bugs or break important code.
Accelerate Application Modernization
In application modernization, code refactoring acts as a bridge between the existing code and the evolving technological landscape that helps ensure the project grows and adapts in a dynamic environment.
Architectural refactoring is often a necessary part of a bigger project to enable new features or facilitate the move to modern paradigms like microservices. Developers transitioning from a monolithic architecture to microservices need to separate functional areas of the monolithic architecture into separate microservices, extract common code into shared libraries or services, and refactor the data layer into multiple databases for each specific microservice.
Regular refactoring also helps teams to keep pace with new development methodologies, tools, and best practices, ensuring that the codebase remains robust and relevant.
Increase Velocity for Agile Development
Agile development can’t exist without refactoring.
The pace of development in an agile environment moves like a high-speed train, with frequent stops to add new features and submit completed tasks while continuously adjusting its requirements based on real-time feedback from customers and stakeholders. These rapid changes and frequent feature additions can lead to a cluttered codebase. In this environment, refactoring is essential to untangle code, improve modularity, and maintain a flexible codebase that can adapt to new requirements without major rewrites.
Without regular refactoring, agile development could very well come to a standstill as developers find themselves mired in the task of fixing and patching existing code—to the extent that introducing new features becomes an insurmountable challenge.
Because software architecture in agile development evolves incrementally, refactoring should also be incremental and proactive, addressing minor issues and inefficiencies as they arise. By planning refactoring efforts, developers can avoid known blockers, like tightly coupled code and deprecated technologies, and prevent merge conflicts.
This continuous improvement approach addresses issues early and, therefore, avoids the accumulation of hacks and workarounds that would cause more extensive and time-consuming refactoring later on.
Help Decouple Code
Highly coupled code increases the dependencies between different parts of the codebase, making it difficult to modify one area of the application without affecting others. Such dependencies make unit testing more challenging, as overlapping responsibilities can lead to complex test setups.
One effective approach to this challenge is incorporating dependency injection (DI) as part of your refactoring efforts. DI frameworks, such as Spring Framework, Google Guice, and Java EE Contexts and Dependency Injection (CDI), let developers supply dependencies externally instead of embedding them in the application. This results in classes that are less dependent on each other and components that can be isolated and tested under controlled conditions without intertwined dependencies.
Decoupling separates code into distinct, independent modules, each responsible for a specific task, allowing for more autonomous development that makes code more testable, maintainable, and scalable.
Improve Software Performance and Scalability
In software development, performance and scalability are often afterthoughts, particularly when rushing to launch a new product or feature to market. While this approach meets immediate business needs, over time, this can create small performance bottlenecks, such as increased latency, memory overhead, or concurrency issues, that can compound, leading to overall inefficiency.
Developers can use code refactoring to address these issues by adopting more efficient algorithms, optimizing data structures to reduce memory overhead and speed up data access, or implementing caching for expensive operations.
However, developers should refactor for performance with caution. Test your changes to ensure performance improvements don’t compromise application functionality or stability. Additionally, consider whether you need to refactor for performance at all. Premature optimization can introduce new problems, such as reduced readability, reduced flexibility, and increased code complexity.
Enhance Developer Productivity and Morale
In the book, ‘Drive: The Surprising Truth About What Motivates Us‘, the author, Daniel Pink identifies three principles crucial for intrinsic motivation: autonomy, mastery, and purpose. He proposes these elements are essential for fostering motivation that leads to greater engagement, satisfaction, and productivity in any field.
Working on a messy codebase full of hacks and shortcuts can be a demotivating experience for developers as it makes code difficult to understand, extend, or maintain. Regular refactoring clarifies the codebase, removes excess complexity, and reduces developer frustration.
By eliminating hacks and shortcuts from the codebase, you minimize the need for future fixes and allow developers to focus on adding value rather than patching problems. This creates a greater sense of ownership and responsibility and makes them more invested in their work.
These are just some of the reasons why refactoring is important, but it’s more than just a technical exercise. It’s a strategic alignment between different stakeholders in a company and is something you need to advocate for.
Advocating for Refactoring to Business Teams
With so many potential benefits for your company, you need to emphasize the business benefits of refactoring (meaning there has to be nontechnical reasons as well) in order to garner support from stakeholders.
Kent Beck, creator of extreme programming and pioneer of software patterns, identifies two types of stakeholders: waiters and changers. Waiters, typically business team members, often see refactoring as a delay, while changers, developers, and engineers understand its importance for a sustainable and efficient codebase.
Misalignment between these groups can cause conflict, even among changers.
To business teams, the initial time investment in refactoring might seem like an unnecessary cost burden. It’s tempting to fulfill the short-term desire to push the next feature as quickly as possible, but an investment in refactoring pays off in the long run. A well-maintained codebase leads to lower maintenance, debugging, and extension costs, not only benefiting the development team but also keeping the business competitive and flexible in a fast-paced market.
However, the business benefits of refactoring go beyond code improvement and touch upon critical aspects, such as strategic alignment, cost optimization, human relationships, and long-term sustainability. By refactoring code, teams can create a flexible and modular codebase that can quickly adapt to shifting business priorities and new strategic initiatives, allowing the organization to respond more nimbly to market changes and customer demands.
Tips for Effective Refactoring
To implement refactoring effectively, proper planning is necessary. Developers and engineers also need to understand the process, tools, and methodologies involved. Here are a few tips to help you refactor effectively:
Let IDEs Play a Key Role
Refactoring often involves decoupling different parts of the codebase. As you decouple and rearrange code, it’s easy to break existing contracts between different parts of the system, leading to unexpected behavior. Hardening API contracts, which involves defining clear, consistent interfaces and thoroughly documenting expected behaviors, helps to maintain the integrity of linkages as you decouple.
Integrated development environments (IDEs) not only offer a wide range of refactoring patterns but also provide features such as code suggestions, syntax highlighting, and code navigation that can help you refactor code more efficiently.
For instance, some Java IDEs, such as Eclipse and NetBeans provide refactoring patterns such as rename, change method signature, and extract method. IntelliJ IDEA also offers advanced features such as duplicate code detection.
IDEs also offer tools for deprecating APIs, API versioning, and API contract testing that make it easier to identify and fix potential issues during the refactoring process.
Implement Vital Unit Testing
Unit testing is an essential part of the entire refactoring process. Before refactoring, ensure you have a comprehensive set of unit tests covering the parts of the code you want to refactor. This is especially important when working with a large or complex codebase because writing unit tests requires extensive effort to understand how the existing code behaves, leading to increased time and costs associated with the refactoring process.
Additionally, without unit tests, it’s difficult, if not impossible, to determine if your changes have accidentally introduced bugs or changed important functionality. Make sure that while you’re refactoring, you regularly run unit tests to ensure that you haven’t unintentionally broken important functionality.
In larger codebases, maintaining unit tests can prove challenging due to increased codebase complexity and interconnectivity. As the codebase and number of unit tests grow, writing isolated tests becomes harder, making maintenance more difficult. Thankfully, that’s an area where Diffblue Cover’s autonomous unit test generation can help manage this complexity.
Finally, after refactoring, remember to update your unit tests to reflect the changes made and add new tests if necessary. Unit tests act as a verification tool that allows developers to make significant changes confidently while ensuring that code behavior doesn’t change.
Keep in Mind the Human Element
Not all refactoring adds value. You need to use insights and judgment to determine if refactoring will yield the improvements you’re looking for or if it’s merely a cosmetic alteration.
Additionally, refactoring should align with organizational goals and enhance the product or process. It’s a collective effort that requires the coordination and cooperation of everyone involved.
The team must agree on what needs to be done, how, and why. Make sure you engage experienced team members in decision-making. Seasoned developers can weigh the costs and benefits, foresee potential challenges, and create a refactoring strategy that maximizes value without undermining the existing work.
Refactoring activities also need to be timed appropriately so that they don’t conflict with other priorities, such as pending pull requests or imminent releases. Strategic timing helps avoid unnecessary delays and conflicts.
Accelerate Refactoring with AI
Current software development trends indicate that AI tools are increasingly aiding developers in the software development and testing process. AI tools like Diffblue Cover can significantly speed up the refactoring process of your Java applications, making them more efficient and reliable.
For instance, manual unit test writing, often the most time-consuming aspect of refactoring, can be automated with tools like Diffblue Cover, freeing developers to focus on building great applications and creating direct commercial value. Automation generates more tests in less time, providing broader coverage that helps detect issues early in the development cycle. AI-powered tools can also generate tests with higher precision than manual creation.
When refactoring legacy code, which often lacks proper documentation and tests, tools like Diffblue Cover are invaluable for quickly generating the necessary unit tests. Diffblue Cover also integrates seamlessly into existing development workflows, aligning with continuous integration systems to ensure testing stays in step with refactoring.
Final Thoughts
Regular code refactoring is essential for maintaining high-quality, efficient, and scalable software. Moreover, it promotes a proactive approach to software architecture evolution, supports modern software methodologies, and helps align software development with business goals.
Additionally, keep in mind that unit tests are a vital part of the refactoring process and provide a safety net for early issue detection. AI for Code solutions like Diffblue Cover can accelerate refactoring by automating comprehensive unit test generation, offering immediate feedback, and reducing regressions.
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Try Diffblue Cover today and get started with AI-generated unit tests.
