A God class, also known as a God object, is a term used in object-oriented programming to describe a class that knows too much or does too much. This type of class violates the Single Responsibility Principle (SRP), one of the core principles of good software design encapsulated in the SOLID acronym. The SRP states that a class should have only one reason to change, meaning it should only have one job or responsibility[1][9].
The main reasons to avoid God classes include:
Complexity: God classes tend to accumulate a large number of methods, variables, and responsibilities, making them overly complex and difficult to understand. This complexity can lead to a codebase that is hard to navigate and maintain[1][2].
Tight Coupling: Because God classes often control or interact with many different aspects of a system, they tend to be tightly coupled with many other classes. This tight coupling makes it difficult to modify or extend the system without affecting the God class, leading to a fragile codebase where changes in one area can unintentionally impact others[1][2].
Difficulties in Testing: The complexity and tight coupling of God classes make them hard to test. Since they interact with many parts of the system, setting up tests can be cumbersome, and ensuring comprehensive test coverage becomes challenging. This can lead to a lack of confidence in the system's reliability and maintainability over time[1][3].
Inhibits Reusability: The lack of modularity and encapsulation in God classes means that their functionality is not easily reusable in other parts of the system or in different projects. This can lead to code duplication and a decrease in overall code quality[1][2].
Maintenance Challenges: As the system evolves, the God class tends to grow even larger as new features and responsibilities are added. This continuous growth exacerbates th...
