I think OOP is exposing serious flaws in how humans write software and solve problems. I'm not sure, but it seems there is an impedance mismatch in how we write code, and how we'd like to test code, but there is a reluctance or outright defiance toward the idea of writing testable code.
The FP community doesn't seem to have a problem so much with testing simply because they mostly write pure functions that are data in -> data out and that is the easiest thing in the world to test.
It occurs to me that most developers aren't writing testable OO code, and thus we have a never-ending argument about the most clever way to test (or not test) code that is not easily tested in isolation.
If we never get around to writing testable code, we aren't going to have systems that are easy to test. If we don't have easy to test systems, testing is going to suck and people won't do it.
I don't know that FP is the answer, but just asking people to write better OO systems isn't working. The problem certainly is more fundamental than simply TDD or mocking or whatever language or tool we are using.
The problem is in how we look at solving problems in code and how that relates to system maintenance over time. It's a people problem, not a tooling one.
I don't think there is enough of an FP community doing large, heavily tested systems to allow accurate generalisations like that. I can think of plenty "We used FP, and everything went better than expected!" articles, but you probably don't hear from the people who tried, but came across problems.
I agree, and I don't know that FP is the solution.
I just know that the OO design approach isn't working super well with the people who are using it, and we now have a couple decades where design hasn't progressed significantly on the average project.
So, how to we change the human behavior that is leading to less than ideal outcomes?
The FP community doesn't seem to have a problem so much with testing simply because they mostly write pure functions that are data in -> data out and that is the easiest thing in the world to test.
It occurs to me that most developers aren't writing testable OO code, and thus we have a never-ending argument about the most clever way to test (or not test) code that is not easily tested in isolation.
If we never get around to writing testable code, we aren't going to have systems that are easy to test. If we don't have easy to test systems, testing is going to suck and people won't do it.
I don't know that FP is the answer, but just asking people to write better OO systems isn't working. The problem certainly is more fundamental than simply TDD or mocking or whatever language or tool we are using.
The problem is in how we look at solving problems in code and how that relates to system maintenance over time. It's a people problem, not a tooling one.