I've had several conversations where fans of Hooks will justify them by saying that "functional programming is about composition over inheritance".
And I think that's entirely missing the point of functional programming. The goal wasn't to remove inheritance in favor of composition, it was to remove STATE - which in turn results in the nice property that functions can be composed, because they take all relevant data as arguments (they are pure).
Hooks basically blow that away - you've added back in all the problems of local state, but now you've hidden it behind a brand new paradigm that developers just don't have a very good feel for (even years after the introduction of hooks).
I'm reasonably well-versed with hooks, and even I find myself having to do incredibly complicated and deep dives into upstream code to answer simple questions, like "How many times will this hook run?" or "How many render cycles will this hook introduce?".
Sometimes the answer is so far upstream it's basically impossible to answer without running code - Ex: if you depend on the "useLocation" hook from react-router-dom, and you pass the entire object as a dep to useEffect (which is a mistake in and of itself), you will be fine in the browser, but Jest tests will trigger an infinite render cycle, because JSDom generates a new object for each call of window.location.
I can reason about functions that are pure, and that's the freaking point of functional programming. I cannot reason about functions with hooks in them - it's FAR worse than class based components in basically every way except ease of re-use.
I think in many respects - we threw out the baby with the bathwater.
> And I think that's entirely missing the point of functional programming. The goal wasn't to remove inheritance in favor of composition, it was to remove STATE - which in turn results in the nice property that functions can be composed, because they take all relevant data as arguments (they are pure).
I came here to see this said...regardless of the method used, state is what is challenging to maintain, regardless of how your framework or tool modifies and tracks it. And the only way I know of to properly wrap some sense of sanity around complex state modification is with unit tests, again, regardless of framework/tool. If you can't test it with a unit test, then you're going to struggle manually testing it as well, even if it does usually work.
A side-note is that I always thought the obvious split for functional/class-based React components was stateless/stateful (as full-blown objects are basically purpose-built for tracking state), so I was surprised when I joined this new project at my employer and learned about the interesting world of hooks. I rarely dabble in React however.
My snarky side today wants to add "developers struggle with maintaining state, what else is new".
I've had several conversations where fans of Hooks will justify them by saying that "functional programming is about composition over inheritance".
And I think that's entirely missing the point of functional programming. The goal wasn't to remove inheritance in favor of composition, it was to remove STATE - which in turn results in the nice property that functions can be composed, because they take all relevant data as arguments (they are pure).
Hooks basically blow that away - you've added back in all the problems of local state, but now you've hidden it behind a brand new paradigm that developers just don't have a very good feel for (even years after the introduction of hooks).
I'm reasonably well-versed with hooks, and even I find myself having to do incredibly complicated and deep dives into upstream code to answer simple questions, like "How many times will this hook run?" or "How many render cycles will this hook introduce?".
Sometimes the answer is so far upstream it's basically impossible to answer without running code - Ex: if you depend on the "useLocation" hook from react-router-dom, and you pass the entire object as a dep to useEffect (which is a mistake in and of itself), you will be fine in the browser, but Jest tests will trigger an infinite render cycle, because JSDom generates a new object for each call of window.location.
I can reason about functions that are pure, and that's the freaking point of functional programming. I cannot reason about functions with hooks in them - it's FAR worse than class based components in basically every way except ease of re-use.
I think in many respects - we threw out the baby with the bathwater.