Ian Cambridge has put together a new post for his site focusing on the Single Responsibility Principle, one of the more well-known (and well understood) parts of the SOLID design principles.

Single Responsibility Principle (SRP) is probably one of the most well-known principles from SOLID. At its core is a desire to prevent classes from becoming overwhelming and bloated. While enabling the ability to change how a single thing works by only changing a single class. So the benefits of SRP are that you have an easier codebase to maintain since classes are less complex and when you wish to change something you only have to change a single class. In this blog, I will go through some ways to try and help avoid breaching SRP while doing code review.

He gives two examples and the code they might contain, breaking the SRP mentality. The first is a "manager" (or service) class that, while good in principle, usually ends up performing way too many operations than it should. The second is a "from usage" instance where the return of one method is being used as a parameter for another method in the same class. For each he talks about the problem with the current implementation and offers a suggestion or two of things to fix to make it adhere more to SRP ideals.