Shotgun Surgery is a term used in software engineering to describe a situation where a single change or modification to a system's codebase requires multiple small changes to be made in several different parts of the code. This often occurs in systems with poor design or tightly coupled components, making it difficult to implement a change without affecting other parts of the system. Shotgun Surgery is considered an anti-pattern, as it can lead to decreased maintainability, increased likelihood of introducing bugs, and overall complexity in the codebase.
Causes of Shotgun Surgery
- Tightly Coupled Components: When components within a system are highly dependent on each other, a change in one part of the system may require changes in other related parts to maintain consistency and avoid breaking the functionality.
- Poor Design: A lack of proper software design principles, such as encapsulation, separation of concerns, and modularization, can lead to code that is difficult to understand, modify, and maintain, increasing the likelihood of Shotgun Surgery.
- Code Duplication: Repetitive code or copy-pasting existing code instead of reusing or abstracting common functionality may cause a situation where changes must be made in multiple places, increasing the risk of errors or inconsistencies.
- Lack of Documentation: Insufficient or outdated documentation can make it challenging to understand the relationships and dependencies within a system, leading to the need for multiple changes when modifying the code.
How to Prevent Shotgun Surgery
- Refactoring: Refactor the code to improve its design, eliminate code duplication, and reduce coupling between components. Techniques such as "Extract Method," "Move Method," and "Extract Class" can help to simplify the code and make it more maintainable.
- Adhere to Design Principles: Follow established software design principles, such as the SOLID principles, to ensure the system is modular, maintainable, and easy to understand.
- Code Review: Regularly review the codebase for potential issues, including signs of Shotgun Surgery, and address them proactively to improve the overall quality and maintainability of the system.
- Documentation: Keep documentation up to date and provide clear explanations of the relationships and dependencies within the system to help developers understand the impact of their changes and minimize the need for Shotgun Surgery.
In summary, Shotgun Surgery is an anti-pattern in software engineering that occurs when a single change in a codebase requires multiple small changes in various parts of the system. This is often due to poor design, tightly coupled components, or code duplication. To prevent Shotgun Surgery, developers should refactor the code, adhere to established design principles, perform regular code reviews, and maintain proper documentation.