independently-controllable rules

[John Ruble]

I'd like to disable A hook cannot be used inside of another function, but keep all the others (e.g. A hook cannot appear inside an if statement), but they seem to be all fall under the rule react-hooks-nesting.

Can rules be independently controlled?

[Grzegorz Rozdzialik]

@jrr This is a solid suggestion 👍 Initially, I went with the approach eslint-plugin-react-hooks introduced to have everything under one rule.

It can be changed, though. I will consider splitting the rule into multiple ones with lesser individual scopes

Out of curiosity, what is your use case for enabling hooks in regular functions? 😄

[John Ruble]

Initially I'd like to set all the rules I'm already in compliance with to "error", and then put the rest on "warning" until we get around to fixing them.

For this particular rule, though, there may be some places we'll never comply, and think it's Probably Okay. For example, when we need to call a hook from tests or storybook, which make heavy use of lambdas.

[Grzegorz Rozdzialik]

I gave some thought into this issue. Having multiple rules means that the parser and rule logic would have to be invoked multiple times due to the limitations of TSLint. One walker cannot report violations of multiple rules.

This can still be achieved, it's just that the performance may be worse than when having a single rule with controllable options.

How about adding options to a single react-hooks-nesting rule? Then, you would be able to allow using hooks in any function. The configuration could be as follows:

"react-hooks-nesting": {
  "severity": "error",
  "options": {
    "allow-using-hooks-in-all-functions": true
  }
}

That would make the rule walker ignore violations connected with checking the function's name.

What do you think? Would that be sufficient?

[John Ruble]

Thanks for looking into this!

Having multiple rules means that the parser and rule logic would have to be invoked multiple times due to the limitations of TSLint. One walker cannot report violations of multiple rules.

Yikes, that's disappointing. Do you happen to know if ESLint (with the ts parser) has this limitation?

Your proposal would unblock me on this issue, but doesn't help with the general goal of granularly tightening rules, gradually over time.

I wouldn't bother unless anyone else is clamoring for it; I'll probably just keep severity set to warning, suppress in source code, and/or try my luck with ESLint.

[Grzegorz Rozdzialik]

I think I might have worded that incorrectly. I meant that the walker and rule logic would have to be invoked multiple times. The parser runs once and parses the file into an AST that is then provided to every rules' walkers.

Still, the walker (the class that explores the AST) has to once for every rule and for every CallExpression (essentially for every function call in a file) has to check whether it is a hook call and check its ancestors to determine if it is inside a switch etc.

This is not as bad as running the parser multiple times but still adds some overhead compared to a single rule with one walker that reports violations conditionally, based on the options.

I wouldn't bother unless anyone else is clamoring for it; I'll probably just keep severity set to warning, suppress in source code, and/or try my luck with ESLint.

Sure, I will consider splitting it into multiple rules in the future, but currently, I do not have the time to implement it.

I heard create-react-app wants to use ESLint with the TS parser when using Typescript, so trying ESLint may be a solid idea 👍 For more information on this, take a look at facebook/create-react-app#5641

[John Ruble]

Closing because the world has moved on to eslint.