What is meant by code refactoring?

In computer programming, code refactoring is a process of reconstructing the already existing computer code. It improves the structure design and application of the software while preserving its functional properties. Because changes are so small, it is improbable that they will create and introduce any new errors. There are many ways to begin refactoring, but it most frequently consists of applying a sequence of standardized, basic actions, occasionally known as micro-refactoring.

Purpose of refactoring

Refactoring improves the code by making it:

• More well-organized by addressing dependencies and difficulties
• More sustainable or refillable by increasing efficacy and readability
• Cleaner, so it is easier to read and comprehend
• Easier for software inventors to find and fix bugs or susceptibilities in the code

Code modification is done without altering any functions of the program itself. Numerous elementary editing environments support simple Refactoring like renaming a purpose or adjusting across an entire code base.

The procedure of code refactoring

Red-Green-Refactor

Red-green refactoring is one of the most widely used methods for code refactoring in agile test-driven development. The developers break down refactoring into three steps by applying the Red-Green-Refactor method: 

• Stop and reflect on what needs to be developed [RED]
• Get the development to permit the basic testing [GREEN]
• Implements enhancements [REFACTOR]

Refactoring by abstraction

Refracting by abstraction is primarily used when much refracting is needed. It includes class inheritances, hierarchy, and extraction. The abstraction aims to overcome the needless duplications in software code.

• Example: an example of abstraction is the Pull-Up/Push-Down method. These are two opposite refactoring forms, including classes.
• Pull-Up process: it pulls the parts of code into a superclass and transfers them into subclasses.
• Push-Down process: it takes the code fragment from a superclass and moves it down into the particular subclasses. Take the constructor body, extract subclass, extract superclass, form template method, collapse hierarchy, replace Inheritance, extract interface with the delegation, replace delegation with Inheritance, push down-field all these are additional examples of abstraction.

Principally, this method shapes the abstraction layer for those fragments of the system that desire to be refactored and the complement that will ultimately substitute it. Other examples are:

• Encapsulated field: force the code to access the field with getter and setter procedures.
• Generalize type: generate more general categories to permit code distribution, change type-checking code with the state, replace provisional with polymorphism, etc.

Composing method

The composing method is mainly used to understand the long methods. Throughout the application development phase, there are many lengthy procedures in the program. These make code tremendously hard to comprehend and hard to change.

So, streamlined methods are used to overcome duplication in code. Some examples include:

• Extract method
• Extract a variable
• Inline temp
• Replace temp with Query
• Inline method
• Split temporary variable
• Remove assignments to parameters, etc.

Simplifying methods

These are two methods included:

Simplifying conditional expressions refactoring

In programming, the Conditional statement in programming develops more reasonably and is difficult with time. There are numerous methods to refactor the code and then simplify the logic. Some of them are consolidating conditional expression and duplicate conditional fragments, decomposing conditional, replacing conditional with polymorphism, removing control flag, replacing nested conditional with guard clauses, etc.

Simplifying method calls refactoring

This approach makes the method calls convenient and easier to understand. Examples are addition, deduction, introducing another parameter, overriding the pa parameter with the explicit method and method call, parameterizing the method, making a separate query from the modifier, preserving the whole object, removing the setting method, etc. 

Moving features between objects

In this technique, create the new classes and then move the functionality between old and new classes. Hide the operation details from public access.

Preparatory refactoring

This technique is best when refactoring is needed by adding certain new features to an application. Principally, it is a fragment of a software update with a distinct refactoring development. The end-user cannot see the engineering team's efforts, but the inventors working on the application will find the worth of refactoring the code when they structure the application. It can save time, money, and other possessions if little time is spent updating the code.

Maintenance issues recognized with software refactoring

The most common maintenance issues included poor names, duplicate code, dead code, and poor names.

Poor names

Poor or wrong names can greatly affect the code readability. Names should not be indefinite, confusing, or noisy. It should not contain unnecessary elements. A good and appropriate name should include descriptive and enough words for developers to get it rapidly.

Duplicate code

Duplicate code makes it difficult for developers to replicate the same logic. Writing it is a waste of time and money, and it enhances needless difficulty to your solution, affecting its presentation. Repetition of the same line of code increases the chance of bugs during updates.

Dead code

The dead code issue frequently happens during the progressing development process when the necessities are modified. To another condition, the team jumps, leaving old lines behind. It is valuable to remove it to decrease the complication of your solution and prevent your application from performing needless tasks that disturb its complete performance of the system.

When you refactor your code?

Before adding any update

The best time for refactoring the code is before adding any updates or new features to the existing code. Firstly, go back and clean up the current code that is applied before adding a new one. New programming will not only affect the quality of the product but will also make it easier and more helpful for future programming to develop on the original code.

After delivering the product

Again, you must refactor your code when delivering your product to the client. It means when we launch any product, we have been working for a time. It is the best time for refactoring. Developers now have more chances to work on refactoring before moving toward any next job.

What are the challenges of refactoring?

Some challenges of refactoring include:

• If the development team is in a rush and refactoring is not prearranged, the procedure will take extra time.
• When the objectives are unclear, refactoring can lead to delays, slowness, and extra work.
• Refactoring cannot address software bugs by itself, as it is made to clean code and make it less complex.

Code refactoring best practices

The top practices to follow for refactoring comprise:

• Plan for refactoring – it might be tough to make time for the time-consuming preparation otherwise.
• Refactor first – developers should do this before the addition of any updates or before any new features to existing code to overcome the technical debt in the system.
• Refactor in small steps – this provides the creator's response early in the development so they can find the possible bugs, as well as comprise business requests.
• Set clear objectives – creators should regulate the project's scope and the project's goals early in the process of code refactoring. This aids in avoiding delays and extra work, as refactoring is destined to be a form of housekeeping, not a chance to vary purposes or features.
• Fix software defects separately – refactoring is not destined to address software drawbacks. Troubleshooting and debugging would be done distinctly.
• Understand the code – analyze the code to recognize its procedures, methods, objects, variables, and other fundamentals.
• Refactor, patch, and update regularly – refactoring produces the most return on investment when addressing an important issue without taking too much time and energy.
• Focus on code de-duplication – duplication enhances difficulties in code, increasing the software footprint and wasting system possessions.

Conclusion - why is it essential to refactor code?

Code refactoring is crucial because it can improve the maintainability and readability of code by breaking down the composite code into smaller or more meaningful portions. It can also regulate the code's style and improve the code base's general design. This approach makes it easier for other developers to comprehend and work with the code later.