As a Java engineer in the web development industry for several years now, having heard multiple times that X is good because of SOLID principles or Y is bad because it breaks SOLID principles, and having to memorize the “good” ways to do everything before an interview etc, I find it harder and harder to do when I really start to dive into the real reason I’m doing something in a particular way.
One example is creating an interface for every goddamn class I make because of “loose coupling” when in reality none of these classes are ever going to have an alternative implementation.
Also the more I get into languages like Rust, the more these doubts are increasing and leading me to believe that most of it is just dogma that has gone far beyond its initial motivations and goals and is now just a mindless OOP circlejerk.
There are definitely occasions when these principles do make sense, especially in an OOP environment, and they can also make some design patterns really satisfying and easy.
What are your opinions on this?
Like anything else, it can be useful in the right context if not followed too dogmatically, and instead is used when there is a tangible benefit.
For example, I nearly always dependency inject dependencies with I/O because I can then inject test doubles with no I/O for fast and stable integration tests. Sometimes, this also improves re-usability, and for example, a client for one vendor’s API can be substituted with another, but this benefit doesn’t materialize that often. I rarely dependency inject dependencies with no side-effects because it’s rare that any tangible benefit materializes, and everyone deals with the additional complexity for years with no reason. With just I/O dependencies, I’ve generally found no need for a DI container in most codebases, but codebases that dependency inject everything make a DI container basically mandatory, and its usually extra overhead for nothing, IMO. There may be codebases where dependency injecting everything makes perfect sense, but I haven’t found one yet.