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?
That one is indeed objective horse shit. If your interface has only one implementation, it should not be an interface. That being said, a second implementation made for testing COUNTS as a second implementation, so context matters.
In general, I feel like OOP principals like are indeed used as dogma more often than not, in Java-land and .NET-land. There’s a lot of legacy applications out there run by folks who’ve either forgotten how to apply these principles soundly, or were never taught to in the first place. But I think it’s more of a general programming trend, than any problem with OOP or its ecosystems in particular. Betcha we see similar things with Rust, when it reaches the same age.
SOLID often comes up against YAGNI (you ain’t gonna need it).
What makes software so great to develop (as opposed to hardware) is that you can (on the small scale) do design after implementation (i.e. refactoring). That lets you decide after seeing how your new bit fits in whether you need an abstraction or not.
Yeah… Interfaces are great, but not everything needs an interface.
I ask myself: How likely is this going to have an alternative implementation in the future?
If the answer is “kinda likely”, it gets an interface. If the answer is “idk, probably not? Why would it?” then it does not get an interface.
Of course these days it’s more likely to be an unnecessary trait than an unnecessary interface. For me, I mean.