Episode 55: Refactoring Pt. 2

Compatibility

Maintaining backward compatibility while evolving APIs is a complex challenge. Martin Fowler highlights the difficulties faced by projects like the JDK and Eclipse, where ensuring binary compatibility across versions is crucial. He explains that techniques such as using interfaces and abstract implementations can help manage these changes without breaking clients 1. However, this approach can lead to an ever-growing system, making it necessary to occasionally break compatibility to simplify and improve the API 1.

You always think of okay, I need to be backward compatible all the time and I want to change and I want to improve my API, but I need to add API instead of changing it or instead of just making it better.

--- Martin Fowler

Balancing these strategies with manageable release cycles is essential to avoid overwhelming developers and users 2.

   

Change Management

Managing API evolution involves careful planning, especially when unforeseen client interactions are involved. Martin Fowler discusses the use of scripts for data migration and refactoring, which can simplify transitions between schema versions 3. He also mentions scripting refactorings within the Eclipse IDE, allowing clients to automatically adapt to changes in the API 4.

You can script that refactoring and you can publish the script, the refactoring script together with your new version of the API.

--- Martin Fowler

These strategies are particularly useful for large databases where manual migration is impractical, but they require careful implementation to avoid complicating the software further 3.