Clarify that hooks are available in selector function about constate HOT 4 CLOSED

This is not a real problem, omitting setValue from native useCallback is a feature of react-hooks/exhaustive-deps built on the fact that setValue is a reference stable function, so when we pass it to deps of useCallback and useMemo, this always passes change detection, just causing very little performance slowdown.

IMHO the structure of code and separation of concern are generally more important than the little performance slowdown, I will encourage to use hooks inside selector function by myself, at lease I can delete an entire selector function when it is no longer used, not having to remember to delete a part of the root hook's body.

I think we can add a note in document to confirm that hooks are available in selector functions, but not to officially encourage users to use it as a best practice.

from constate.

Yes, you can use hooks inside selectors. That's not a good example though.

Inside the selector, you don't know whether setValue has a stable constant value. By omitting it from the useCallback dependencies, you are at risk of creating a stale callback. So, the right place to put that useCallback would be inside the useValue hook, where you know how setValue has been created.

Because of this, eslint will also complain about that if you use the react-hooks/exhaustive-deps rule.

I'm totally open to update the documentation if we can come up with a better example of hooks inside selectors.

from constate.

omitting setValue from native useCallback is a feature of react-hooks/exhaustive-deps

Not in this case. Since eslint doesn't know where setValue comes from, the function can't be added to the list of exceptions. Since it's not in the same scope, react-hooks/exhaustive-deps has no clue whether this setValue is actually a state setter returned by useState.

But the eslint warning is not the real problem. I'd say the developer maintaining that code may also get confused about that if the original hook is abstracted somewhere else.

I guess we can possibly add that to the docs if we include setValue in the deps array:

useCallback(() => setValue(v => v + 1), [setValue]);

Would you like to send a PR?

from constate.

Closing this issue because of lack of activity. Feel free to send a PR with the suggested documentation.

from constate.