Code Refactoring Techniques

Code refactoring is one of the key terms in software development. In this article let’s consider code refactoring techniques that might increase your efficiency!

About code refactoring

First, of all, let’s start with what code refactoring is. It is a process or logical technique of changing the actual computer program’s source code not changing its external functional behavior so that some non-functional attributes would be upgraded. The most essential benefits of refactoring are enhanced code readability and decreased complexity. It can make the code design modern and easier to work with. Through this process, it becomes possible to boost the maintainability and extensibility of the source code, also a more eloquently internal architecture or object model.


Put in simple terms, refactoring is a series of actions to analyze, define and simplify the design of actual code, without changing its behavior. It also could be a good tip in understanding an unfamiliar code base.

Martin Fowler and Kent Beck, latterly the most significant experts in software development, issued the ABC of refactoring called “Refactoring: Improving the Design of Existing Code”. In this book, you will find clear cases that specify the entire process of refactoring.  It explains how to do the numerous steps of refactoring. You will also get a greater insight into larger questions of refactoring, and the testing function, also about the “code smells” concept. Seventy code refactoring techniques are fully covered in the book.

Benefits of Code Refactoring

  • The vision of Overall Picture

The approach would be too long and extremely complicated, in case there is one primary method that manages all functionality. However you divide it into parts, it’s easy to figure out what is really being done.

  • Productivity

Code refactoring could be thought-out as an investment. The effort required for future changes to the code is reduced so that the efficiency is improved.

  • Make It Readable

Don’t write it for yourself, make it easy to understand.

  • Reduction of Complexity

Make it easier to work on the project.

  • Maintainability

Pay attention to the integration of updates and upgrades. This is a continuous inevitable process that should be welcomed. It is difficult for developers to make any changes, in case the codebase is messed up. So with code refactoring will help to develop the product on a clean foundation and will be ready for future updates.

True Tips for Code Refactoring Techniques

  • The best technique is to refactor in many small changes, that eventually acquire considerable changes and effective impact. Each change improves the actual code at the same time the program remains maintained and kept up-to-date. Small changes will prevent introducing new bugs when refactoring/redesigning the code.
  • The code is going to be cleaner.
  • While refactoring, you should absolutely be using TDD and CI. Otherwise, there is a high probability of bugs introduction.
  • During the process of refactoring, new functionality must not be created. Avoid mixing refactoring and direct development of new features. It is better to disconnect these processes.

List of Main Code Refactoring Techniques

There are many code refactoring techniques. Let’s have a look at the most common and useful. Some of them may only be applied to certain languages or language types. A full list is available in Martin Fowler’s book.

Red-Green Refactoring

Red-green refactor is the Agile engineering pattern which is the basis of Test Driven Development. In the first phase, the programmer writes a test, in the second – the code necessary for the test worked, and in the third, if necessary, refactoring takes place. The phase sequence is very important. In accordance with the principle of “Test First” to design and implementation, you should only write such code that is absolutely essential that the tests are carried out successfully.

As a rule, the “red-green-refactor” cycle should take from 5 to 20 minutes, although exceptions occur. The important thing is to remember to not do both at the same time during the workflow: it is unreasonable to refactor a code, for example, in the “red” phase. The more tests are debugged in one cycle, the worse. Ideally, you only need to work with one test at a time.

Preparatory Refactoring

There are methods that can make the building of your next feature more obvious. At first, this technique had the support for only one payment per billing cycle. To set up multiple payments for customers who make partial payments during the billing cycle, developers first refactored the code and then added the support in the UI for the same. In case the refactoring was delayed, as a result, the system became more complicated.
Martin Fowler named it as a preparatory refactoring. This technique may include paying down technical debt that was accumulated during the earlier phases of feature development.

Branching by Abstraction Refactoring

Branch by Abstraction is a set-piece technique to effect a ‘longer to complete’ change in the trunk. Abstraction has its own group of refactoring techniques, mainly teamed up with moving functionality along the class inheritance hierarchy, creating new classes and interfaces, and replacing inheritance with a delegation and vice versa.

Branching by abstraction is a technique that some of the teams use to take on large-scale refactoring. The basic idea is to build an abstraction layer that wraps the part of the system that is to be refactored and the counterpart that is eventually going to replace it.

Composing Methods Refactoring

It is a very basic pattern of refactoring. Composing method calls out to other methods. It is best applied when all called methods have rawly the same level of detail. Often in longer methods, certain sections are already labelled with a comment; these sections can frequently be extracted into new methods. The vagaries of code inside these methods conceal the execution logic and make the method extremely hard to understand and even harder to change. The code refactoring techniques in this group streamline methods, remove code duplication.

Simplifying Method Calls Refactoring

Simplifying method calls aims to make refactoring technique simpler and easier to comprehend. This simplifies the interfaces for interaction between classes.

Breaking Code Apart Into More Logical Pieces Refactoring

Componentization breaks code down into reusable semantic units that present clear, well-defined, simple-to-use interfaces. By breaking down code in smaller pieces, it is more easily understandable. This is also applicable to functions.


There are many different refactoring techniques that are not included here. The full list you will meet in Martin Fowler’s refactoring book. Some of the techniques may only be applied to certain languages or language types.

In the modern world of software development, we need to understand the significance of software refactoring as an important area of research that gives benefits to code maintenance. Refactoring is a process that improves the quality and allows developers to repair code that is becoming hard to maintain, without throwing away the existing source code and starting again. Refactoring naturally fits in an agile software development process. It is extremely crucial to learn to find the right balance between building your system and refactoring the code that you write. Creating a software culture that boosts clean design and refactoring is not so easy than it may seem, but to work on it is a must.

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