The Ultimate Engineer’s Guide to Code Refactoring

What is code refactoring?

Programming software is a tedious process, involving multiple developers. Thus, the written source code is often reworked, modified and supplemented. For lack of time or because of outdated practices, the source code accumulates dirty lines, which are called “code smells”. These weak points developed over time threaten the application possibilities and the compatibility of a program. To avoid the progressive erosion and degradation of software, it is necessary to go through the reworking of the code.

This process is significantly more cost effective than writing an entirely new code. For iterative and incremental software development, such as agile software development, refactoring is critical because in this cyclical model programmers continually make changes to their software. Refactoring is a constant work step.

What is the purpose of refactoring?

The purpose of reworking code is outright to produce better code. An efficient code allows better integration of new elements, without generating new errors. If it doesn’t take a lot of effort to read the code, programmers will find their way around faster and can fix or avoid bugs more easily. Refactoring also aims to simplify the analysis of errors and the maintainability of a software. Dedicated development team feels their job lightened when they control source code.

What sources of errors can refactoring correct?

The techniques used to rework code are as varied as the errors they need to correct. Basically, refactoring is defined according to errors and shows the steps necessary to shorten or remove a resolution method. The sources of errors that can be corrected during reworking of the code are, among others:

• Fuzzy or too long methods: Command lines and blocks are so long that outsiders cannot understand the internal logic of the software.
• Duplicates (redundancies): superfluous code often contains redundancies which, at the maintenance stage, must be modified separately for each entry. They therefore generate working time and additional costs.
• Too long lists of parameters: instead of responding directly to a method, objects have their attributes transmitted to a list of parameters.
• Classes with too many functions: Classes with too many functions defined as methods, also known as god objects, which make it almost impossible to modify the software.
• Classes with too few functions: classes with too few functions defined as methods, which are superfluous.
• Codes that are too general with specific cases: functions with particular cases that are too specific, which only rarely or never occur and make it difficult to add the necessary complements.
• The Middle Men: a separate class acts as an intermediary between methods and different classes, while methods could directly call a class.

When we rework a code, what approach should we adopt?

Refactoring should always take place before modifying a program function. It is best to proceed by very small steps and test changes to the code with software development process, such as the development test driven (TDD Test Driven Development) or continuous integration (CI for Continuous Integration). In summary, TDD and CI recommend continually testing the small, newly added sections of code, which programmers create, integrate, and functionally control through automated and frequent testing.

The golden rule: modify the program from the inside in small steps without touching the external functions. After each modification, start a test cycle that is as automated as possible.

What techniques exist?

There are many concrete refactoring techniques. Ask or hire offshore developers to understand them in detail:

–      Red-green development

Red-green development is a test-driven method of agile software development. It applies when you want to integrate a new function into an existing code. The red symbolizes the first cycle of tests, before the implementation of the new function in the code. Green symbolizes the simplest possible section of code necessary for this function to pass the test. This results in an extension with continuous test cycles to resolve faulty lines of code and increase functionality. Red-green development is a pillar of continuous refactoring within the framework of also continuous software development.

–      Branching-by-Abstraction

This method of reworking code describes modifying a system in stages and adapting old implemented lines of code to new sections of code. Branching-by-Abstraction is typically used when making large changes involving class hierarchy, inheritance, or extraction. Implementing an abstraction that remains linked to an old implementation allows you to link other methods and classes to the abstraction and replace the functionality of the old section of code with that same abstraction.

–      Compile methods

Refactoring should make the code methods as readable as possible. Ideally, right off the bat, even an outside programmer should be able to understand the internal logic of a method. To efficiently compile the methods, reworking the code offers different techniques. The goal of each change is to distinguish each method, remove duplicates, and break up longer methods into separate pieces to allow for later modification.

Offset properties between different classes
To improve a code, we sometimes have to shift the attributes or methods from one class to another. Here are the suitable techniques:

• Shift a method
• Offset an attribute
• Extract a class
• Add inline to the class
• Hide delegates
• Remove an intermediate class
• Insert an external method
• Insert a local extension

Data organization

The purpose of this method is to distribute the data within the classes and to keep it as short and clear as possible. Unnecessary links between classes, which hinder the proper functioning of the software from the slightest modification, must be removed and distributed among the appropriate classes.

Simplify conditional expressions

During refactoring,conditional expressions should be simplified as much as possible. Example of adapted techniques:

• Split relationships
• Merge conditional expressions
• Merge repeated statements into conditional expressions
• Remove control buttons
• Replace nested conditions with guardians
• Replace distinctions with polymorphisms
• Insert null objects

Simplify method invocation

The invocation of methods becomes faster and easier thanks to the following techniques, among others:

• Rename methods
• Add parameters
• Delete parameters
• Replace parameters with explicit methods
• Replace the wrong code with exceptions

Author Bio:

Nasrullah Patel Co-founder Peerbits, one of the leading offshore development team providers. He guided many companies to hire offshore remote developers team from Peerbits for their complex and customized projects. His years of hard work, dedication, and experience has helped him in developing profound expertise for a wide array of technologies, tools, and platforms. He believes in sharing his strong knowledge base with a learned concentration on entrepreneurship and business.